socket调用服务端

public String socketClient(String request) throws Exception{
        StringBuilder sb = new StringBuilder();
        //客户端
        //1、创建客户端Socket，指定服务器地址和端口
        Socket socket = new Socket(SOCKET_URL, Integer.parseInt(SOCKET_PORT));
        //2、获取输出流，向服务器端发送信息
        //字节输出流
        OutputStream os = socket.getOutputStream();
        //将输出流包装成打印流
        PrintWriter pw = new PrintWriter(os);
        pw.write(request);
        pw.flush();
        socket.shutdownOutput();
        //3、获取输入流，并读取服务器端的响应信息
        InputStream is = socket.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(is,"GBK"));
        String str;
        while((str = br.readLine()) != null){
            sb.append(str);
        }
        //4、关闭资源
        br.close();
        is.close();
        pw.close();
        os.close();
        socket.close();

        return sb.toString();
    }