要在Java项目中调用Dify接口，并将流式对话消息传递给前端（Vue项目），你可以使用Spring Boot作为后端框架，并通过WebSocket或Server-Sent Events (SSE) 实现流式传输。以下是一个简单的示例，展示如何在Java后端调用Dify接口，并将流式响应传递给Vue前端。

1. Java后端（Spring Boot）

1.1 添加依赖

首先，在pom.xml中添加必要的依赖：

    
    
        org.springframework.boot
        spring-boot-starter-web
    

    
    
        org.springframework.boot
        spring-boot-starter-websocket
    

    
    
        com.squareup.okhttp3
        okhttp
        4.9.3
    

1.2 创建WebSocket配置

import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(new ChatWebSocketHandler(), "/chat").setAllowedOrigins("*");
    }
}

1.3 创建WebSocket处理器

import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import java.io.IOException;

public class ChatWebSocketHandler extends TextWebSocketHandler {

    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        String userMessage = message.getPayload();
        // Call Dify API and stream the response
        streamDifyResponse(userMessage, session);
    }

    private void streamDifyResponse(String userMessage, WebSocketSession session) throws IOException {
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url("https://api.dify.ai/v1/chat") // Dify API endpoint
                .post(RequestBody.create(userMessage, MediaType.parse("application/json")))
                .build();

        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response.isSuccessful()) {
                    try (ResponseBody responseBody = response.body()) {
                        if (responseBody != null) {
                            BufferedReader reader = new BufferedReader(responseBody.charStream());
                            String line;
                            while ((line = reader.readLine()) != null) {
                                session.sendMessage(new TextMessage(line));
                            }
                        }
                    }
                }
            }
        });
    }
}

1.4 启动Spring Boot应用

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

@SpringBootApplication
public class DifyChatApplication {

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

2. Vue前端

2.1 安装WebSocket库

npm install vue-native-websocket

2.2 在Vue组件中使用WebSocket

<script>
import VueNativeSock from 'vue-native-websocket'

export default {
  data() {
    return {
      message: '',
      messages: []
    }
  },
  created() {
    VueNativeSock('ws://localhost:8080/chat', {
      format: 'json',
      reconnection: true,
      reconnectionAttempts: 5,
      reconnectionDelay: 3000,
    })
  },
  sockets: {
    connect() {
      console.log('WebSocket connected')
    },
    message(data) {
      this.messages.push(data)
    }
  },
  methods: {
    sendMessage() {
      this.$socket.send(this.message)
      this.message = ''
    }
  }
}
</script>

3. 运行项目

1. 启动Spring Boot应用。
2. 启动Vue前端项目。
3. 在Vue前端输入消息，消息将通过WebSocket发送到Java后端，Java后端调用Dify API并将流式响应返回给前端。

总结

这个示例展示了如何使用Spring Boot和Vue实现一个简单的流式聊天应用。Java后端通过WebSocket与前端通信，并调用Dify API获取流式响应。前端通过WebSocket接收并显示流式消息。你可以根据实际需求进一步扩展和优化这个示例。