目录

1、介绍

2、入门案例

（1）LangcChain4J支持的语言模型

（2）获取百炼平台信息

1）获取Key

2）获取模型名称

3）获取baseUrl

（3）创建父工程

1）创建工程

2）修改pom文件

（4）建立第一个案例模块

1）新建模块

2）修改pom文件

3）添加配置文件

4）添加配置类

5）编写业务类

6）测试

（5）多模型共存(deepseek)

1）获取Key

2）获取模型名称

3）获取baseUrl

（6）修改工程

1）修改配置类

2）修改业务类

3）测试

3、与springBoot整合

（1）了解

（2）案例实现

1）新建模块

2）修改pom文件

3）添加配置文件

4）低阶Api业务类

5）自定义接口类

6）高阶Api业务类

7）测试

4、低阶Api和高阶Api

（1）介绍

（2）案例实现

1）新建模块

2）修改pom文件

3）添加配置文件

4）添加配置类

5）低阶api调用业务类

6）测试低阶api调用

7）修改业务类获取Token调用

8）高阶api调用

1、定义AiServices接口

2、修改配置类

3、业务类

9）测试高阶api

5、模型的参数配置

（1）日志配置

1）修改配置类

2）修改配置文件

3）测试

（2）监控配置

1）编写监听类

2）修改配置类

3）测试

（3）重试机制

1）修改配置类

2）测试

（4）超时机制

1）修改配置类

2）测试

6、多模态视觉

（1）出处

（2）图形理解案例实现

1）创建模块

2）修改pom

3）添加配置文件

4）添加配置类

5）编写业务类

6）测试

（3）引入第三方案例实现

0）修改父工程pom文件

1）创建模块

2）修改pom

3）添加配置文件

4）添加配置类

5）编写业务类

6）测试

7、流式输出

（1）介绍

（2）案例实现

1）创建模块

2）修改pom

3）添加配置文件

4）自定义接口

5）编写配置类

6）编写业务类

7）测试

8、记忆存储

（1）介绍

（2）案例实现

1）新建模块

2）修改pom文件

3）添加配置文件

4）自定义接口

5）编写配置类

6）编写业务类

7）测试

9、提示词工程

（1）出处

（2）案例实现

1）基础工程搭建

2）方式一

3）方式二

4）方式三

10、持久化

11、Tools工具

12、向量数据库

13、RAG检索增强

14、MCP模型上下文切换

1、介绍

LangChain4j 的目标是简化将大型语言模型集成到 Java 应用中

官网地址https://docs.langchain4j.dev/文档地址https://docs.langchain4j.dev/get-started

2、入门案例

（1）LangcChain4J支持的语言模型

支持的模型地址https://docs.langchain4j.dev/category/language-models案例中使用阿里的通义千问和deepseek模型

（2）获取百炼平台信息

1）获取Key

地址https://bailian.console.aliyun.com/

2）获取模型名称

qwen-plus

3）获取baseUrl

https://dashscope.aliyuncs.com/compatible-mode/v1

（3）创建父工程

1）创建工程

2）修改pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.hk</groupId>
    <artifactId>langcChain4J-study</artifactId>
    <version>1.0-SNAPSHOT</version>

    <packaging>pom</packaging>
    <name>langchain4j-study父工程</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>17</java.version>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <!-- Spring Boot -->
        <spring-boot.version>3.5.0</spring-boot.version>
        <!-- Spring AI -->
        <spring-ai.version>1.0.0</spring-ai.version>
        <!-- Spring AI Alibaba -->
        <spring-ai-alibaba.version>1.0.0-M6.1</spring-ai-alibaba.version>
        <!-- langchain4j -->
        <langchain4j.version>1.0.1</langchain4j.version>
        <!--langchain4j-community 引入阿里云百炼平台依赖管理清单-->
        <langchain4j-community.version>1.0.1-beta6</langchain4j-community.version>
        <!-- maven plugin -->
        <maven-deploy-plugin.version>3.1.1</maven-deploy-plugin.version>
        <flatten-maven-plugin.version>1.3.0</flatten-maven-plugin.version>
        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring Boot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- Spring AI -->
            <dependency>
                <groupId>org.springframework.ai</groupId>
                <artifactId>spring-ai-bom</artifactId>
                <version>${spring-ai.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- Spring AI Alibaba -->
            <dependency>
                <groupId>com.alibaba.cloud.ai</groupId>
                <artifactId>spring-ai-alibaba-starter</artifactId>
                <version>${spring-ai-alibaba.version}</version>
            </dependency>
            <!--langchain4j的依赖清单，加载BOM后所有langchain4j版本号可以被统一管理起来
            https://docs.langchain4j.dev/get-started
            -->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-bom</artifactId>
                <version>${langchain4j.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--引入阿里云百炼平台依赖管理清单
           https://docs.langchain4j.dev/integrations/language-models/dashscope
           -->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-community-bom</artifactId>
                <version>${langchain4j-community.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>${maven-deploy-plugin.version}</version>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>
                <configuration>
                    <release>${java.version}</release>
                    <compilerArgs>
                        <compilerArg>-parameters</compilerArg>
                    </compilerArgs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>flatten-maven-plugin</artifactId>
                <version>${flatten-maven-plugin.version}</version>
                <inherited>true</inherited>
                <executions>
                    <execution>
                        <id>flatten</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>flatten</goal>
                        </goals>
                        <configuration>
                            <updatePomFile>true</updatePomFile>
                            <flattenMode>ossrh</flattenMode>
                            <pomElements>
                                <distributionManagement>remove</distributionManagement>
                                <dependencyManagement>remove</dependencyManagement>
                                <repositories>remove</repositories>
                                <scm>keep</scm>
                                <url>keep</url>
                                <organization>resolve</organization>
                            </pomElements>
                        </configuration>
                    </execution>
                    <execution>
                        <id>flatten.clean</id>
                        <phase>clean</phase>
                        <goals>
                            <goal>clean</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <releases>
                <enabled>false</enabled>
            </releases>
        </repository>
        <repository>
            <id>aliyunmaven</id>
            <name>aliyun</name>
            <url>https://maven.aliyun.com/repository/public</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>public</id>
            <name>aliyun nexus</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>
</project>

（4）建立第一个案例模块

1）新建模块

2）修改pom文件

文档出处https://docs.langchain4j.dev/get-started

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langcChain4J-01study</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--所有调用均基于 OpenAI 协议标准，实现一致的接口设计与规范LangChain4j 提供与许多 LLM 提供商的集成
        从最简单的开始方式是从 OpenAI 集成开始https://docs.langchain4j.dev/get-started    -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <!--langchain4j 高阶-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8001
spring.application.name=langchain4j-01study
4）添加配置类
@Configuration
public class LLMConfig {

    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .modelName("qwen-plus")
                .build();
    }
}
5）编写业务类
@RestController
public class Study01Controller {

    @Resource
    private ChatModel chatModel;

    @GetMapping("/chat")
    public String chat(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        return chatModel.chat(msg);
    }
}
6）测试

（5）多模型共存(deepseek)

官网地址https://platform.deepseek.com/usage

1）获取Key

2）获取模型名称

3）获取baseUrl

https://api.deepseek.com/v1

（6）修改工程

1）修改配置类
@Configuration
public class LLMConfig {

    @Bean("qwen")
    public ChatModel qwenChatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .modelName("qwen-plus")
                .build();
    }

    @Bean("deepseek")
    public ChatModel deepseekChatModel() {
        return OpenAiChatModel.builder()
                .apiKey("sk-4af********")
                .baseUrl("https://api.deepseek.com/v1")
                .modelName("deepseek-chat")
                .build();
    }
}
2）修改业务类
@RestController
public class Study01Controller {

    @Resource(name = "qwen")
    private ChatModel qwenChatModel;

    @Resource(name = "deepseek")
    private ChatModel deepseekChatModel;

    @GetMapping("/chat/v1")
    public String chatV1(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        return qwenChatModel.chat(msg);
    }

    @GetMapping("/chat/v2")
    public String chatV2(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        return deepseekChatModel.chat(msg);
    }
}
3）测试

3、与springBoot整合

（1）了解

官网地址https://docs.langchain4j.dev/tutorials/spring-boot-integration

（2）案例实现

1）新建模块

2）修改pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-02boot</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j原生 基础-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <!--langchain4j原生 高阶-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <!--1 LangChain4j 整合boot底层支持-->
        <!--   https://docs.langchain4j.dev/tutorials/spring-boot-integration  -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai-spring-boot-starter</artifactId>
        </dependency>
        <!--2 LangChain4j 整合boot高阶支持-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-spring-boot-starter</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8002

spring.application.name=langchain4j-02boot

# https://docs.langchain4j.dev/tutorials/spring-boot-integration
langchain4j.open-ai.chat-model.api-key=${aliQwen-api}
langchain4j.open-ai.chat-model.model-name=qwen-plus
langchain4j.open-ai.chat-model.base-url=https://dashscope.aliyuncs.com/compatible-mode/v1
4）低阶Api业务类
@RestController
public class PopularIntegrationsController {

    @Resource
    private ChatModel chatModel;
    
    @GetMapping("/chatv1")
    public String chat(String msg) {
        return chatModel.chat(msg);
    }
}
5）自定义接口类
@AiService
public interface ChatAssistant {

    String chat(String prompt);
}
6）高阶Api业务类
@RestController
public class DeclarativeAIServiceController {

    @Resource
    private ChatAssistant chatAssistant;

    @GetMapping("/chatv2")
    public String chat(String msg) {
        return chatAssistant.chat(msg);
    }
}
7）测试

4、低阶Api和高阶Api

（1）介绍

官网地址https://docs.langchain4j.dev/intro/#2-levels-of-abstraction        

        低阶api 有最多的选择，可以使用所有底层组件，比如ChatModel等。 这些是基于LLM的应用中的“primitives”。 可以完全控制组合它们，但需要写更多的代码。UserMessage AiMessage 

EmbeddingStore Embedding

        高阶api 在程序员自己定义接口，通过AiServices类里面的方法实现，优点是Api封装度较高，减少代码的复杂度，但是仍可以进行微调

（2）案例实现

1）新建模块

2）修改pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-03lowhigh</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai 基础-->
        <!--所有调用均基于 OpenAI 协议标准，实现一致的接口设计与规范LangChain4j 提供与许多 LLM 提供商的集成
        从最简单的开始方式是从 OpenAI 集成开始https://docs.langchain4j.dev/get-started    -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <!--langchain4j 高阶-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8003
spring.application.name=langChain4j-03lowhigh
4）添加配置类
@Configuration
public class LLMConfig {
    
    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }
}
5）低阶api调用业务类
@RestController
public class LowApiController {

    @Resource
    private ChatModel chatModel;

    @GetMapping("/chat1")
    public String chat1(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        return chatModel.chat(msg);
    }
}
6）测试低阶api调用

7）修改业务类获取Token调用
@RestController
public class LowApiController {

    @Resource
    private ChatModel chatModel;

    @GetMapping("/chat1")
    public String chat1(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        return chatModel.chat(msg);
    }

    @GetMapping("/chat2")
    public String chat2(@RequestParam(name = "msg", defaultValue = "你是谁") String msg) {
        ChatResponse chatResponse = chatModel.chat(UserMessage.from(msg));
        String text = chatResponse.aiMessage().text();
        TokenUsage tokenUsage = chatResponse.tokenUsage();
        System.out.println("本次token消耗：" + tokenUsage);
        return text;
    }
}

8）高阶api调用

官网地址https://docs.langchain4j.dev/tutorials/ai-services#simplest-ai-service

1、定义AiServices接口
public interface ChatAssistant {
    String chat(String prompt);
}
2、修改配置类

AiService接口实现

package com.hk.study.config;

import com.hk.study.service.ChatAssistant;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;
import dev.langchain4j.service.AiServices;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class LLMConfig {

    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }

    @Bean
    public ChatAssistant chatAssistant(ChatModel chatModel) {
        return AiServices.create(ChatAssistant.class, chatModel);
    }
}
3、业务类
@RestController
public class HighApiController {

    @Resource
    private ChatAssistant chatAssistant;

    @GetMapping("chatv2")
    public String chatv2 (String msg) {
        return chatAssistant.chat(msg);
    }
}
9）测试高阶api

5、模型的参数配置

在03模块的基础上配置

官网地址https://docs.langchain4j.dev/tutorials/model-parameters

（1）日志配置

官网地址https://docs.langchain4j.dev/tutorials/logging

1）修改配置类
    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                // 开启日志, 日志级别设置为DEBUG才会打印日志
                .logRequests(true)
                .logResponses(true)
                .build();
    }
2）修改配置文件
server.port=8003
spring.application.name=langChain4j-03lowhigh

# 开启langchain4j的日志, 日志级别设置为DEBUG才会打印日志
logging.level.dev.langchain4j=DEBUG
3）测试

（2）监控配置

官网地址https://docs.langchain4j.dev/tutorials/observability

1）编写监听类
public class TestChatModelListener implements ChatModelListener {

    @Override
    public void onRequest(ChatModelRequestContext requestContext) {
        // onRequest配置的k:v键值对，在onResponse阶段可以获得，上下文传递参数好用
        String uuidValue = IdUtil.simpleUUID();
        requestContext.attributes().put("TraceID",uuidValue);
        System.out.println("配置请求参数：TraceID == "+ uuidValue);
    }

    @Override
    public void onResponse(ChatModelResponseContext responseContext) {
        Object object = responseContext.attributes().get("TraceID");

        System.out.println("获取请求参数：TraceID == "+ object);
    }

    @Override
    public void onError(ChatModelErrorContext errorContext) {
        System.out.println("出错了...");
    }
}
2）修改配置类
    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .listeners(List.of(new TestChatModelListener()))
                .build();
    }
3）测试

（3）重试机制

1）修改配置类
    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .logRequests(true)
                .logResponses(true)
                .maxRetries(2)
                .build();
    }
2）测试

断开网络，再次访问

（4）超时机制

1）修改配置类
    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .logRequests(true)
                .maxRetries(2)
                .timeout(Duration.ofSeconds(1))
                .build();
    }
2）测试

6、多模态视觉

（1）出处

官网地址https://docs.langchain4j.dev/tutorials/chat-and-language-models#multimodalityUserMessage不仅可以包含文本，还可以包含其他类型的内容。 包含一个 。 是一个接口，具有以下实现方式：UserMessageList<Content> contentsContent

  • TextContent
  • ImageContent
  • AudioContent
  • VideoContent
  • PdfFileContent

本次选择的模型：qwen-vl-max

阿里地址https://help.aliyun.com/zh/model-studio/models#850732b1aabs0

（2）图形理解案例实现

1）创建模块

2）修改pom
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-04chatimage</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai 基础-->
        <!--所有调用均基于 OpenAI 协议标准，实现一致的接口设计与规范LangChain4j 提供与许多 LLM 提供商的集成
        从最简单的开始方式是从 OpenAI 集成开始https://docs.langchain4j.dev/get-started    -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <!--langchain4j 高阶-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.22</version>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8004
spring.application.name=langchain4j-04chatimage
4）添加配置类
@Configuration
public class LLMConfig {

    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-vl-max")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }
}
5）编写业务类
@RestController
public class ImageModelController {

    @Resource
    private ChatModel chatModel;

    @Value("classpath:mi.jpg")
    private org.springframework.core.io.Resource imageResource;

    @GetMapping("/image")
    public String image() throws IOException {
        // 1、将图片通过Base64编码转为字符串
        byte[] imageBytes = imageResource.getContentAsByteArray();
        String encodeToString = Base64.getEncoder().encodeToString(imageBytes);
        // 2、构建提示词userMessage
        UserMessage userMessage = UserMessage.from(
                TextContent.from("从以下图片中获取来源网站名称，股价走势和5月30号股价"),
                ImageContent.from(encodeToString, "image/jpg")
        );
        // 3、调用模型获取回答
        ChatResponse chatResponse = chatModel.chat(userMessage);
        String response = chatResponse.aiMessage().text();
        return response;
    }

}
6）测试

（3）引入第三方案例实现

结合阿里巴巴的通义万象进行图像理解，所有出处均来自官网，模型使用阿里的wanx2.1-t2i-turbo

官网文档地址https://docs.langchain4j.dev/integrations/language-models/dashscope

0）修改父工程pom文件

<properties>

        ......

        <!--langchain4j-community 引入阿里云百炼平台依赖管理清单-->
        <langchain4j-community.version>1.0.1-beta6</langchain4j-community.version>

        ........

</properties>

<dependencyManagement>

        ......

        <!--引入阿里云百炼平台依赖管理清单
           https://docs.langchain4j.dev/integrations/language-models/dashscope
           -->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-community-bom</artifactId>
                <version>${langchain4j-community.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

        ......

</dependencyManagement>

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.hk</groupId>
    <artifactId>langcChain4J-study</artifactId>
    <version>1.0-SNAPSHOT</version>

    <packaging>pom</packaging>
    <name>langchain4j-study父工程</name>
    <modules>
        <module>langChain4J-01study</module>
        <module>langChain4J-02boot</module>
        <module>langChain4j-03lowhigh</module>
        <module>langChain4j-04chatimage</module>
    </modules>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>17</java.version>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <!-- Spring Boot -->
        <spring-boot.version>3.5.0</spring-boot.version>
        <!-- Spring AI -->
        <spring-ai.version>1.0.0</spring-ai.version>
        <!-- Spring AI Alibaba -->
        <spring-ai-alibaba.version>1.0.0-M6.1</spring-ai-alibaba.version>
        <!-- langchain4j -->
        <langchain4j.version>1.0.1</langchain4j.version>
        <!--langchain4j-community 引入阿里云百炼平台依赖管理清单-->
        <langchain4j-community.version>1.0.1-beta6</langchain4j-community.version>
        <!-- maven plugin -->
        <maven-deploy-plugin.version>3.1.1</maven-deploy-plugin.version>
        <flatten-maven-plugin.version>1.3.0</flatten-maven-plugin.version>
        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring Boot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- Spring AI -->
            <dependency>
                <groupId>org.springframework.ai</groupId>
                <artifactId>spring-ai-bom</artifactId>
                <version>${spring-ai.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- Spring AI Alibaba -->
            <dependency>
                <groupId>com.alibaba.cloud.ai</groupId>
                <artifactId>spring-ai-alibaba-starter</artifactId>
                <version>${spring-ai-alibaba.version}</version>
            </dependency>
            <!--langchain4j的依赖清单，加载BOM后所有langchain4j版本号可以被统一管理起来
            https://docs.langchain4j.dev/get-started
            -->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-bom</artifactId>
                <version>${langchain4j.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--引入阿里云百炼平台依赖管理清单
           https://docs.langchain4j.dev/integrations/language-models/dashscope
           -->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-community-bom</artifactId>
                <version>${langchain4j-community.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring-boot.version}</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>${maven-deploy-plugin.version}</version>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>
                <configuration>
                    <release>${java.version}</release>
                    <compilerArgs>
                        <compilerArg>-parameters</compilerArg>
                    </compilerArgs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>flatten-maven-plugin</artifactId>
                <version>${flatten-maven-plugin.version}</version>
                <inherited>true</inherited>
                <executions>
                    <execution>
                        <id>flatten</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>flatten</goal>
                        </goals>
                        <configuration>
                            <updatePomFile>true</updatePomFile>
                            <flattenMode>ossrh</flattenMode>
                            <pomElements>
                                <distributionManagement>remove</distributionManagement>
                                <dependencyManagement>remove</dependencyManagement>
                                <repositories>remove</repositories>
                                <scm>keep</scm>
                                <url>keep</url>
                                <organization>resolve</organization>
                            </pomElements>
                        </configuration>
                    </execution>
                    <execution>
                        <id>flatten.clean</id>
                        <phase>clean</phase>
                        <goals>
                            <goal>clean</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <releases>
                <enabled>false</enabled>
            </releases>
        </repository>
        <repository>
            <id>aliyunmaven</id>
            <name>aliyun</name>
            <url>https://maven.aliyun.com/repository/public</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>public</id>
            <name>aliyun nexus</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>
</project>
1）创建模块

2）修改pom
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-05chatimage</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai 基础-->
        <!--所有调用均基于 OpenAI 协议标准，实现一致的接口设计与规范LangChain4j 提供与许多 LLM 提供商的集成
        从最简单的开始方式是从 OpenAI 集成开始https://docs.langchain4j.dev/get-started    -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <!--langchain4j 高阶-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <!--DashScope (Qwen)接入阿里云百炼平台
            https://docs.langchain4j.dev/integrations/language-models/dashscope
        -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-community-dashscope-spring-boot-starter</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.22</version>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8005
spring.application.name=langchain4j-05chatimage
4）添加配置类
@Configuration
public class LLMConfig {

    @Bean
    public WanxImageModel wanxImageModel() {
        return WanxImageModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("wanx2.1-t2i-turbo")
                .build();
    }
}
5）编写业务类
@RestController
public class ImageModelController {

    @Resource
    private WanxImageModel wanxImageModel;

    @GetMapping("/chat/image-1")
    public String image1() {
        Response<Image> generate = wanxImageModel.generate("一张图，描述：一个人在沙滩上");
        return generate.content().url().toString();
    }

    @GetMapping("/chat/image-2")
    public String image2() throws NoApiKeyException {
        String prompt = "近景镜头，18岁的中国女孩，古代服饰，圆脸，正面看着镜头，" +
                "民族优雅的服装，商业摄影，室外，电影级光照，半身特写，精致的淡妆，锐利的边缘。";
        ImageSynthesisParam build = ImageSynthesisParam.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .model("wanx2.1-t2i-turbo")
                .prompt(prompt)
                .n(2)
                .size("1024*1024")
                .build();
        ImageSynthesis imageSynthesis = new ImageSynthesis();
        ImageSynthesisResult result = imageSynthesis.call(build);
        return JsonUtils.toJson(result);
    }
}
6）测试

7、流式输出

（1）介绍

        流式输出(StreamingOutput)是一种逐步返回大模型生成结果的技术，允许服务器将响应内容分批次实时传输给客户端，而不是等待全部内容生成完毕后再一次性返回。这种机制能显著提升用户体验，尤其适用于大模型响应较慢的场景（如生成长文本或复杂推理结果）。

低阶出处https://docs.langchain4j.dev/tutorials/response-streaming高阶出处https://docs.langchain4j.dev/tutorials/ai-services#flux

（2）案例实现

1）创建模块

2）修改pom
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-06chatstream</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai + langchain4j + langchain4j-reactor-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-reactor</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.22</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>
3）添加配置文件
server.port=8006

spring.application.name=langchain4j-06chat-stream

# 设置响应的字符编码，避免流式返回输出乱码
server.servlet.encoding.charset=utf-8
server.servlet.encoding.enabled=true
server.servlet.encoding.force=true
4）自定义接口
public interface ChatAssistant {

    Flux<String> chat(String prompt);
}
5）编写配置类
@Configuration
public class LLMConfig {

    @Bean
    public StreamingChatModel streamingChatModel() {
        return OpenAiStreamingChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-plus")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }

    @Bean
    public ChatAssistant chatAssistant(StreamingChatModel streamingChatModel){
        return AiServices.create(ChatAssistant.class, streamingChatModel);
    }
}
6）编写业务类
@RestController
public class StreamingChatModelController {

    @Resource
    private StreamingChatModel streamingChatModel;

    @Resource
    private ChatAssistant chatAssistant;

    // 方式一：使用 Flux.create 手动创建 Flux
    @GetMapping("/chat1")
    public Flux<String> chat1(String msg) {
        return Flux.create(fluxSink -> {
            streamingChatModel.chat(msg, new StreamingChatResponseHandler() {

                @Override
                public void onPartialResponse(String s) {
                    System.out.println(s);
                    fluxSink.next(s);
                }

                @Override
                public void onCompleteResponse(ChatResponse chatResponse) {
                    System.out.println("---response over: "+chatResponse);
                    fluxSink.complete();
                }

                @Override
                public void onError(Throwable throwable) {
                    fluxSink.error(throwable);
                }
            });
        });
    }

    // 方式二
    @GetMapping("/chat2")
    public Flux<String> chat2(String msg) {
        return chatAssistant.chat(msg);
    }
}
7）测试

8、记忆存储

（1）介绍

        记忆缓存是聊天系统中的一个重要组件，用于存储和管理对话的上下文信息。它的主要作用是让AI助手能够"记住"之前的对话内容，从而提供连贯和个性化的回复

官网地址https://docs.langchain4j.dev/tutorials/chat-memoryLangChain4j 提供两种开箱即用实现：

  • 滑动窗口：只保留最新的N条消息 MessageWindowChatMemory
  • 限制Token数量：它同样作为滑动窗口，保留最新的令牌TokenWindowChatMemory，需要结合TokenCountEstimator来计算Token的数量

（2）案例实现

1）新建模块

2）修改pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-07chatmemory</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai + langchain4j + langchain4j-reactor-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-reactor</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.22</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
3）添加配置文件
server.port=8007

spring.application.name=langchain4j-07chat-memory

# 设置响应的字符编码
server.servlet.encoding.charset=utf-8
server.servlet.encoding.enabled=true
server.servlet.encoding.force=true
4）自定义接口
public interface ChatMemoryAssistant {
    /**
     * 聊天带记忆缓存功能
     *
     * @param userId  用户 ID
     * @param prompt 消息
     * @return String
     */
    String chatWithChatMemory(@MemoryId Long userId, @UserMessage String prompt);
}
5）编写配置类
@Configuration
public class LLMConfig {

    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-long")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }

    @Bean("chatMessageWindowChatMemory")
    public ChatMemoryAssistant chatMessageWindowChatMemory(ChatModel chatModel) {
        return AiServices.builder(ChatMemoryAssistant.class)
                .chatModel(chatModel)
                // 每个memoryId对应创建一个ChatMemory
                .chatMemoryProvider(memoryId -> MessageWindowChatMemory.withMaxMessages(20))
                .build();
    }

    @Bean
    public ChatMemoryAssistant chatTokenWindowChatMemory(ChatModel chatModel) {
        // TokenCountEstimator默认的token分词器，需要结合Tokenizer计算ChatMessage的token数量
        OpenAiTokenCountEstimator openAiTokenCountEstimator = new OpenAiTokenCountEstimator("gpt-4");
        return AiServices.builder(ChatMemoryAssistant.class)
                .chatModel(chatModel)
                // 每个memoryId对应创建一个ChatMemory
                .chatMemoryProvider(memoryId -> TokenWindowChatMemory.withMaxTokens(100, openAiTokenCountEstimator))
                .build();
    }
}
6）编写业务类
@RestController
public class ChatMemoryController {

    @Resource(name = "chatMessageWindowChatMemory")
    private ChatMemoryAssistant chatMessageWindowChatMemory;

    @Resource(name = "chatTokenWindowChatMemory")
    private ChatMemoryAssistant chatTokenWindowChatMemory;

    // MessageWindowChatMemory实现聊天功能
    @GetMapping("/chatv1")
    public void chatv1() {
        chatMessageWindowChatMemory.chatWithChatMemory(1L, "你好！我的名字是Java.");
        String answer01 = chatMessageWindowChatMemory.chatWithChatMemory(1L, "我的名字是什么");
        System.out.println("answer01返回结果："+answer01);

        chatMessageWindowChatMemory.chatWithChatMemory(3L, "你好！我的名字是C++");
        String answer02 = chatMessageWindowChatMemory.chatWithChatMemory(3L, "我的名字是什么");
        System.out.println("answer02返回结果："+answer02);
    }

    // TokenWindowChatMemory实现聊天功能
    @GetMapping("/chatv2")
    public void chatv2() {
        chatTokenWindowChatMemory.chatWithChatMemory(1L, "你好！我的名字是Java.");
        String answer01 = chatTokenWindowChatMemory.chatWithChatMemory(1L, "我的名字是什么");
        System.out.println("answer01返回结果："+answer01);

        chatTokenWindowChatMemory.chatWithChatMemory(3L, "你好！我的名字是C++");
        String answer02 = chatTokenWindowChatMemory.chatWithChatMemory(3L, "我的名字是什么");
        System.out.println("answer02返回结果："+answer02);
    }
}
7）测试

GET http://localhost:8007/chatv1

9、提示词工程

（1）出处

官网地址https://docs.langchain4j.dev/tutorials/chat-and-language-models

五种类型的聊天的消息：

  • SystemMessage：系统消息，通常，作为开发人员，你应该定义这条消息的内容。通常，你会在这里写关于LLM在这次对话中的角色、应该如何表现、以什么风格回答等指令。
  • UserMessage：用户消息；这是用户发来的信息。 用户可以是你应用的最终用户（人类）或你的应用本身
  • AiMessage：由AI生成的消息；
  • ToolExecutionResultMessage：模型结合工具
  • CustomMessage： 这是一个可以包含任意属性的自定义消息。这种消息类型只能被支持它的实现使用（目前仅支持 Ollama）。

（2）案例实现

1）基础工程搭建
  • 创建模块

  • 修改pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.hk</groupId>
        <artifactId>langcChain4J-study</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>langChain4j-08chatprompt</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--langchain4j-open-ai + langchain4j + langchain4j-reactor-->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j</artifactId>
        </dependency>
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-reactor</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.22</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>
  • 添加配置文件
server.port=8008

spring.application.name=langchain4j-08chat-prompt

# 设置响应的字符编码
server.servlet.encoding.charset=utf-8
server.servlet.encoding.enabled=true
server.servlet.encoding.force=true
2）方式一

@SystemMessage + @UserMessage + @V

  • 编写自定义接口
public interface LawAssistant {

    @SystemMessage("你是一位专业的中国法律顾问，只回答与中国法律相关的问题。" +
            "输出限制：对于其他领域的问题禁止回答，直接返回'抱歉，我只能回答中国法律相关的问题。'")
    @UserMessage("请回答以下法律问题：{{question}},字数控制在{{length}}以内")
    String chat(@V("question") String question, @V("length") int length);
}
  • 添加配置类
@Configuration
public class LLMConfig {

    @Bean
    public ChatModel chatModel() {
        return OpenAiChatModel.builder()
                .apiKey(System.getenv("aliQwen-api"))
                .modelName("qwen-long")
                .baseUrl("https://dashscope.aliyuncs.com/compatible-mode/v1")
                .build();
    }

    @Bean
    public LawAssistant lawAssistant(ChatModel chatModel) {
        return AiServices.create(LawAssistant.class, chatModel);
    }
}
  • 编写业务类
@RestController
public class ChatPromptController {

    @Resource
    private LawAssistant lawAssistant;

    @GetMapping(value = "/chatprompt/test1")
    public void test1() {
        String chat = lawAssistant.chat("什么是知识产权？",2000);
        System.out.println(chat);

        System.out.println("========================================================");
        String chat2 = lawAssistant.chat("什么是java？",2000);
        System.out.println(chat2);

        System.out.println("========================================================");
        String chat3 = lawAssistant.chat("介绍下西瓜和芒果",2000);
        System.out.println(chat3);

        System.out.println("========================================================");
        String chat4 = lawAssistant.chat("飞机发动机原理",2000);
        System.out.println(chat4);

    }
}

3）方式二

使用@structuredPrompt业务实体类

  • 新建业务实体类
@Data
@StructuredPrompt("根据中国{{legal}}法律，解答以下问题：{{question}}")
public class LawPrompt {
    private String legal;
    private String question;
}
  • 修改自定义接口
public interface LawAssistant {

    @SystemMessage("你是一位专业的中国法律顾问，只回答与中国法律相关的问题。" +
            "输出限制：对于其他领域的问题禁止回答，直接返回'抱歉，我只能回答中国法律相关的问题。'")
    @UserMessage("请回答以下法律问题：{{question}},字数控制在{{length}}以内")
    String chat(@V("question") String question, @V("length") int length);

    @SystemMessage("你是一位专业的中国法律顾问，只回答与中国法律相关的问题。" +
            "输出限制：对于其他领域的问题禁止回答，直接返回'抱歉，我只能回答中国法律相关的问题。'")
    String chat(LawPrompt lawPrompt);
}
  • 修改业务类测试
@RestController
public class ChatPromptController {

    @Resource
    private LawAssistant lawAssistant;

    ......

    @GetMapping(value = "/chatprompt/test2")
    public String test2() {
        LawPrompt prompt = new LawPrompt();

        prompt.setLegal("知识产权");
        prompt.setQuestion("TRIPS协议?");

        String chat = lawAssistant.chat(prompt);
        System.out.println(chat);
        return chat;
    }
}

4）方式三

        在LangChain4j中有两个对象PromptTemplate以及Prompt用来实现提示词相关功能

单个参数可以使用{it}"占位符或者"{{参数名}"，如果为其他字符，系统不能自动识别会报错。

  • 修改业务类测试
    @Resource
    private ChatModel chatModel;
    
    @GetMapping(value = "/chatprompt/test3")
    public String test3(){
        // 默认 PromptTemplate 构造使用 it 属性作为默认占位符
        String role = "财务会计";
        String question = "人民币大写";

        //1 构造PromptTemplate模板
        PromptTemplate template = PromptTemplate.from("你是一个{{it}}助手,{{question}}怎么办");
        //2 由PromptTemplate生成Prompt
        Prompt prompt = template.apply(Map.of("it",role,"question",question));
        //3 Prompt提示词变成UserMessage
        UserMessage userMessage = prompt.toUserMessage();
        //4 调用大模型
        ChatResponse chatResponse = chatModel.chat(userMessage);
        //4.1 后台打印
        System.out.println(chatResponse.aiMessage().text());
        //4.2 前台返回
        return chatResponse.aiMessage().text();
    }

10、持久化

持续更新中......

11、Tools工具

持续更新中......

12、向量数据库

持续更新中......

13、RAG检索增强

持续更新中......

14、MCP模型上下文切换

持续更新中......

# java # 开发语言
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