java开发连接websocket接口

建立WebSocket连接

使用Java的javax.websocket库建立WebSocket客户端连接。添加Maven依赖：

<dependency>
    <groupId>javax.websocket</groupId>
    <artifactId>javax.websocket-api</artifactId>
    <version>1.1</version>
</dependency>

创建客户端类并实现Endpoint和MessageHandler：

@ClientEndpoint
public class WebSocketClient {
    private Session session;

    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        System.out.println("Connected to server");
    }

    @OnMessage
    public void onMessage(String message) {
        System.out.println("Received: " + message);
        processMessage(message);
    }

    @OnClose
    public void onClose(Session session, CloseReason reason) {
        System.out.println("Disconnected: " + reason.toString());
    }
}

连接WebSocket服务器

使用WebSocketContainer建立连接：

WebSocketContainer container = ContainerProvider.getWebSocketContainer();
container.connectToServer(
    WebSocketClient.class,
    URI.create("ws://your-websocket-server.com:port/path")
);

消息处理与数据解析

实现消息处理方法，使用JSON解析库（如Jackson）处理数据：

private void processMessage(String jsonMessage) {
    ObjectMapper mapper = new ObjectMapper();
    try {
        JsonNode rootNode = mapper.readTree(jsonMessage);
        String action = rootNode.get("action").asText();
        JsonNode data = rootNode.get("data");

        switch (action) {
            case "query":
                handleQueryRequest(data);
                break;
            // 其他action处理
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

数据库查询处理

配置数据库连接（以JDBC为例）：

private void handleQueryRequest(JsonNode queryParams) {
    String queryType = queryParams.get("type").asText();
    String responseKey = queryParams.get("responseKey").asText();

    try (Connection conn = DriverManager.getConnection(DB_URL, USER, PASS)) {
        String sql = buildQuery(queryType, queryParams);
        ResultSet rs = conn.createStatement().executeQuery(sql);
        
        JsonNode result = convertResultSetToJson(rs);
        sendResponse(responseKey, result);
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

构建响应并返回

将查询结果封装为JSON并返回：

private void sendResponse(String responseKey, JsonNode data) {
    ObjectNode response = JsonNodeFactory.instance.objectNode();
    response.put("responseKey", responseKey);
    response.set("data", data);

    try {
        session.getBasicRemote().sendText(response.toString());
    } catch (IOException e) {
        e.printStackTrace();
    }
}

异常处理与重连机制

实现自动重连逻辑：

@OnError
public void onError(Session session, Throwable t) {
    t.printStackTrace();
    if (!session.isOpen()) {
        reconnect();
    }
}

private void reconnect() {
    try {
        Thread.sleep(5000); // 等待5秒后重连
        WebSocketContainer container = ContainerProvider.getWebSocketContainer();
        container.connectToServer(this, URI.create(serverUri));
    } catch (Exception e) {
        e.printStackTrace();
    }
}

完整示例整合

将所有组件整合为完整解决方案：

public class WebSocketApp {
    public static void main(String[] args) {
        try {
            new WebSocketClient().connect();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

@ClientEndpoint
public class WebSocketClient {
    // 之前的所有方法实现...
    
    public void connect() throws Exception {
        WebSocketContainer container = ContainerProvider.getWebSocketContainer();
        container.connectToServer(this, URI.create("ws://your-server.com/ws"));
    }
}

性能优化建议

使用连接池管理数据库连接：

// 使用HikariCP连接池
HikariConfig config = new HikariConfig();
config.setJdbcUrl(DB_URL);
config.setUsername(USER);
config.setPassword(PASS);
HikariDataSource ds = new HikariDataSource(config);

异步处理大量消息：

@OnMessage
public void onMessageAsync(String message) {
    CompletableFuture.runAsync(() -> processMessage(message));
}

安全注意事项

实现WebSocket安全验证：

@OnOpen
public void onOpen(Session session, @HeaderParam("Authorization") String auth) {
    if (!isValidToken(auth)) {
        throw new RuntimeException("Unauthorized");
    }
    this.session = session;
}

SSL/TLS加密连接：

container.connectToServer(
    WebSocketClient.class,
    URI.create("wss://secure-server.com/ws") // 注意wss协议
);