Java Socket网络编程Client端详解

此类实现客户端套接字（也可以就叫“套接字”）。套接字是两台机器之间的通信端点。

Socket client = new Socket(ip,port);//创建一个流套接字并将其连接到指定 IP 地址的指定端口号。

以下为完整的客户端示例：

SocketClientDemo.java

public class SocketClientDemo
{
    /**
     * 向指定的地址发送请求数据
     * @param ipAddr
     * @param reqData
     */
    public void sendReq(String ipAddr,String reqData)
    {
        Socket client = null;
        BufferedReader br = null;
        BufferedOutputStream bos = null;
        String respStr = "";

        //设置字符集编码格式
        String characterCoding = "GBK";

        //将ip:port 类型的字符串拆分
        int dotPos = ipAddr.indexOf(":");
        String ip = ipAddr.substring(0, dotPos).trim();
        int port = Integer.parseInt(ipAddr.substring(dotPos+1).trim());

        try
        {
            client = new Socket(ip,port);
            //设置发送等待时间（单位：s）
            client.setSoLinger(true, 5);

            //设置超时时间（单位：ms）
            client.setSoTimeout(5000);

            //从client端获取输出流
            bos = new BufferedOutputStream(client.getOutputStream());
            bos.write(reqData.getBytes(characterCoding));
            bos.flush();

            br = new BufferedReader(new InputStreamReader(client.getInputStream()));
            respStr = br.readLine();
            System.out.println("respStr is:>>>>>>"+respStr);
        }
        catch (UnknownHostException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        finally
        {
            if(br != null)
            {
                try
                {
                    br.close();
                }
                catch (IOException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(bos!=null)
            {
                try
                {
                    bos.close();
                }
                catch (IOException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(client!=null)
            {
                try
                {
                    client.close();
                }
                catch (IOException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

测试类代码：

SocketClientTest.java

public class SocketClientTest
{

    /**
     * @param args
     */
    public static void main(String[] args)
    {
        // TODO Auto-generated method stub
        SocketClientDemo client = new SocketClientDemo();
        client.sendReq("192.168.1.136:9997", "this is socket client!");
    }
}