20250302 langchain+dashscope+deepseek实现简单的ai聊天案例

pom.xml

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+<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.example</groupId>
+    <artifactId>langchain-deepseek-r1</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <!-- Spring Boot Web -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <!-- LangChain Java -->
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-core</artifactId>
+            <version>1.0.0-beta1</version>
+        </dependency>
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-community-bom</artifactId>
+            <version>1.0.0-beta1</version>
+            <type>pom</type>
+            <scope>import</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-community-dashscope-spring-boot-starter</artifactId>
+            <version>1.0.0-beta1</version>
+        </dependency>
+
+    </dependencies>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>3.2.2</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.11.0</version> <!-- 可以根据实际情况调整版本 -->
+                <configuration>
+                    <source>17</source> <!-- 可以根据你的 Java 版本调整 -->
+                    <target>17</target> <!-- 可以根据你的 Java 版本调整 -->
+                    <compilerArgs>
+                        <arg>-parameters</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

src/main/java/com/ai/LiangAiApplication.java

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+package com.ai;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class LiangAiApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(LiangAiApplication.class, args);
+    }
+}

src/main/java/com/ai/config/LanguageModelConfig.java

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+package com.ai.config;
+
+import dev.langchain4j.community.model.dashscope.QwenLanguageModel;
+import dev.langchain4j.model.language.LanguageModel;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class LanguageModelConfig {
+
+    @Value("${langchain4j.community.dashscope.api-key}")
+    private String apiKey;
+
+    @Value("${langchain4j.community.dashscope.model-name}")
+    private String modelName;
+
+    @Bean
+    public LanguageModel languageModel() {
+        return QwenLanguageModel.builder()
+                .apiKey(apiKey)
+                .modelName(modelName)
+                .build();
+    }
+}

src/main/java/com/ai/controller/LangChainController.java

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+package com.ai.controller;
+
+import com.ai.service.LangChainService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/langchain")
+public class LangChainController {
+
+    @Autowired
+    private LangChainService langChainService;
+
+    /**
+     * 处理用户输入并调用 LangChainService 获取响应
+     * @param input 用户输入的内容
+     * @return 大语言模型生成的响应
+     */
+    @GetMapping("/chat")
+    public String chat(@RequestParam("input") String input) {
+        System.out.println("start chat...");
+        return langChainService.getResponse(input);
+    }
+}

src/main/java/com/ai/http/chat.http

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+### 测试 LangChainController 的 chat 接口
+GET http://localhost:8080/langchain/chat?input=今天天气如何

src/main/java/com/ai/service/LangChainService.java

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+package com.ai.service;
+
+import dev.langchain4j.community.model.dashscope.QwenLanguageModel;
+import dev.langchain4j.data.message.UserMessage;
+import dev.langchain4j.model.chat.ChatLanguageModel;
+import dev.langchain4j.model.language.LanguageModel;
+import dev.langchain4j.model.output.Response;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class LangChainService {
+
+    @Autowired
+    private LanguageModel model;
+
+    public String getResponse(String input) {
+        Response<String> response = model.generate(input);
+        return response.content();
+    }
+}

src/main/resources/application.properties

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+server.port=8080
+
+langchain4j.community.dashscope.api-key=sk-2f703a41fff0488e9b6888013d2ee58a
+langchain4j.community.dashscope.model-name=deepseek-r1