TCP入门简单例子

TCP的简单例子

TCP最简单聊天室

客户端

1. 连接服务器 Socket

2. 发送消息

   package TCP;
   
   import java.io.IOException;
   import java.io.OutputStream;
   import java.net.InetAddress;
   import java.net.Socket;
   import java.net.UnknownHostException;
   import java.util.Scanner;
   
   //客户端
   public class TcpClientZx01 {
       public static void main(String[] args) {
           Socket socket=null;
           OutputStream os=null;
           Scanner sc=null;
   
           //1.要知道服务端的地址
           try {
               InetAddress serverIp= InetAddress.getByName("127.0.0.1");
               int port=9090;
   
               //2.建立一个socket连接
               socket=new Socket(serverIp,port);
               os= socket.getOutputStream();
               sc=new Scanner(System.in);
               System.out.println("进入聊天室和邓聊天");
               System.out.println("1为发送");
               String e="";
               while(!e.equals("1")){
                    e=sc.next();
                   os.write(e.getBytes());
   
               }
   
   
   
           } catch (Exception e) {
               e.printStackTrace();
           }finally{
               try {
                   if(os!=null){
                       os.close();
                   }
                   if(socket!=null){
                       socket.close();
                   }
               } catch (IOException e) {
                   e.printStackTrace();
               }
           }
       }
   }
   
   

服务端

1. 建立服务的端口 ServerSocket

2. 等待用户的连接 accept(等待监听)

3. 接受用户的消息

   public class TcpServerZx01 {
   //服务端
       public static void main(String[] args) {
           ServerSocket serverSocket=null;
           Socket accept=null;
           InputStream is=null;
           ByteArrayOutputStream baos=null;
   
           try {
           //1.我得有一个地址
           serverSocket=new ServerSocket(9090);
           	while(true) {
           	    //监听客户端发过来的数据
                   accept=serverSocket.accept();
                   //2.读取客户端的数据
                   is=accept.getInputStream();
                   //管道流
                   baos = new ByteArrayOutputStream();
                   byte[] buf = new byte[1024];
                   int len = 0;
                   while ((len = is.read(buf)) != -1) {
                       baos.write(buf, 0, len);
                   }
               
                   System.out.printf(baos.toString());
           	}
               
   
           } catch (IOException e) {
               e.printStackTrace();
           }finally{
            if(baos!=null) {
           	 try {
           		 baos.close();
   			} catch (IOException e) {
   				// TODO Auto-generated catch block
   				e.printStackTrace();
   			}
            }
            if(is!=null) {
           	 try {
           		 is.close();
   			} catch (IOException e) {
   				// TODO Auto-generated catch block
   				e.printStackTrace();
   			}
            }
            if(accept!=null) {
           	 try {
           		 accept.close();
   			} catch (IOException e) {
   				// TODO Auto-generated catch block
   				e.printStackTrace();
   			}
            }
            if(serverSocket!=null) {
           	 try {
   				serverSocket.close();
   			} catch (IOException e) {
   				// TODO Auto-generated catch block
   				e.printStackTrace();
   			}
            }
           }
   
       }
   }
   
   

TCP最简单文件上传

文件上传:其实就是IO流,把资源转换成流,读取给出

客户端

public class FileTop {
	public static void main(String[] args) throws UnknownHostException, IOException {
		//1.创建一个Socket连接
		Socket socket=new Socket(InetAddress.getByName("127.0.0.1"),9999);
		//2.创建一个输出流
		OutputStream os=socket.getOutputStream();
		
		//3.读取文件
		FileInputStream fis = new FileInputStream(new File("img_7.jpg"));
		
		//4.写出文件
		byte[] buffer=new byte[1024];//这些都是固定代码,如果明确文件大小,可以不声明1024,避免资源浪费
		int len;
		while((len=fis.read(buffer))!=-1) {
			os.write(buffer,0,len);
		}
		
		//通知服务器，我已经传输完了
		socket.shutdownOutput();
		
		//确定服务器接受完毕才能断开连接
		InputStream is = socket.getInputStream();
		ByteArrayOutputStream baos=new ByteArrayOutputStream();
		byte[] buffer2=new byte[1024];
		int len2;
		while((len2=is.read(buffer2))!=-1){
			baos.write(buffer2,0,len2);
		}
        System.out.println(baos.toString());
		//关闭资源,规则都遵循先写后关
		baos.close();
		is.close();
		fis.close();
		os.close();
		socket.close();
		
	}

}

服务端

public class FileDown {

	public static void main(String[] args) throws IOException {
        //1.创建服务
		ServerSocket serverSocket = new ServerSocket(9999); 
		//2.监听客户端的连接
		Socket socket=serverSocket.accept();//监听，会一直等待客户连接
		//3.获取输入流
		InputStream is=socket.getInputStream();
		
		//4.文件输出
		FileOutputStream fos=new FileOutputStream(new File("reactiv.jpg"));
		byte[] buffer=new byte[1024];
		int len;
		while((len=is.read(buffer))!=-1) {
			fos.write(buffer,0,len);
		}

		//通知客户端接收完毕了
		OutputStream os=socket.getOutputStream();
		os.write("我接受完毕了".getBytes());
		
		//5.关闭资源
		fos.close();
		is.close();
		socket.close();
		serverSocket.close();
		
	}

}