JAVA 学习（3，黑马 Java 全套百度云

    Socket socket =null;
    OutputStream os = null;


    try {
       
        InetAddress ServerIP =InetAddress.getByName("127.0.0.1");
        int port = 9999;
        socket = new Socket(ServerIP,port);
        os = socket.getOutputStream();


        os.write("hello , welcome to learn the Java".getBytes());


    } catch (Exception e) {
        e.printStackTrace();
    }finally {


        if(os!=null){
            try {
                os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(socket!=null){
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

服务器


1.  建立服务的端口 ServerSocket
2.  等待用户的连接 accept
3.  接收用户消息

public static void main(String[] args) {
    ServerSocket serverSocket =null;
    Socket socket = null;
    InputStream is = null;
    ByteArrayOutputStream baos = null;


    try {
        serverSocket = new ServerSocket(9999);


        socket = serverSocket.accept();


        is = socket.getInputStream();


        //管道流
        baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len;
        while ((len= is.read(buffer))!=-1){
            baos.write(buffer,0,len);
        }
        System.out.println(baos.toString());


    } catch (IOException e) {
        e.printStackTrace();
    }finally {
        //关闭资源
        if(baos!=null){
            try {
                baos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }


        }
        if(is!= null){
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(socket!=null){
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


        if(serverSocket!=null){
            try {
                serverSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


    }
}

[](https://gitee.com/vip204888/java-p7)Tomcat
=====================================================================


服务器：Tomcat 服务器 S  
客户端： 浏览器 B


[](https://gitee.com/vip204888/java-p7)UDP


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