LangChain4j 集成 SpringBoot的项目实践

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <spring-boot.version>3.2.6</spring-boot.version>
        <knife4j.version>4.3.0</knife4j.version>
        <!-- 截至 2025-08-22 是 1.3.0 -->
        <langchain4j.version>1.3.0</langchain4j.version>
        <mybatis-plus.version>3.5.11</mybatis-plus.version>
    </properties>

    <dependencies>
        <!-- web应用程序核心依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- 编写和运行测试用例 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 前后端分离中的后端接口测试工具 -->
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-openapi3-jakarta-spring-boot-starter</artifactId>
            <version>${knife4j.version}</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <!--引入SpringBoot依赖管理清单-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

server:
  port: 8080

package com.study;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

    <properties>
        <langchain4j.version>1.3.0</langchain4j.version>
    </properties>

    <dependencies>
        <!-- 基于open-ai的langchain4j接口：ChatGPT、deepseek都是open-ai标准下的大模型 -->
        <dependency>
            <groupId>dev.langchain4j</groupId>
            <artifactId>langchain4j-open-ai</artifactId>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <!--引入langchain4j依赖管理清单-->
            <dependency>
                <groupId>dev.langchain4j</groupId>
                <artifactId>langchain4j-bom</artifactId>
                <version>${langchain4j.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

package com.study;

import dev.langchain4j.model.openai.OpenAiChatModel;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class LLMTest {
    /**
     * gpt-4o-mini语言模型接入测试
     */
    @Test
    public void testGPTDemo() {
        //初始化模型
        OpenAiChatModel model = OpenAiChatModel.builder()
        // LangChain4j提供的代理服务器，该代理服务器会将演示密钥替换成真实密钥，再将请求转发给 OpenAI API
        .baseUrl("http://langchain4j.dev/demo/openai/v1") //设置模型api地址
        .apiKey("demo") //设置模型apiKey
        .modelName("gpt-4o-mini") //设置模型名称
        .build();
        // 向模型提问
        String answer = model.chat("你好");
        // 输出结果
        System.out.println(answer);
    }
}