(3)java网络---半双工、全双工
1.半双工
1.1半双工原理：半双工即Half
duplex Communication，是指在通信过程的任意时刻，信息既可由A传到B，又能由B传A，但只能有一个方向上的传输存在。采用半双工方式时，通信系统每一端的发送器和接收器，通过收/发开关转接到通信线上，进行方向的切换，因此，会产生时间延迟。收/发开关实际上是由软件控制的电子开关。
1.2工程结构
1.3服务器端
/**
*服务器端，在9999端口监听,可以通过控制台，回送给客户端信息
*/
packagetest;
importjava.io.BufferedReader;
importjava.io.InputStreamReader;
importjava.io.PrintWriter;
.ServerSocket;
.Socket;
publicclassmyserver2{
publicmyserver2(){
try{
//监听端口，9999
ServerSocketss=newServerSocket(9999);
//阻塞，等待连接
Sockets=ss.accept();
//先接受到客户端发来的信息
InputStreamReaderisr=newInputStreamReader(s.getInputStream());
BufferedReaderbr=newBufferedReader(isr);
PrintWriterpw=newPrintWriter(s.getOutputStream(),true);
InputStreamReaderisr2=newInputStreamReader(System.in);
BufferedReaderbr2=newBufferedReader(isr2);
while(true){
StringinfoFromClient=br.readLine();
System.out.println("客户端："+infoFromClient);
if(infoFromClient.equals("bye")){
s.close();
break;
}
//接受从控制台输入的信息
System.out.println("请输入您希望对客户端说的话:");
Stringre=br2.readLine();
//把从控制台接受的信息，回送给客户端
pw.println(re);
}
}catch(Exceptione){
//TODO:handleexception
}
}
publicstaticvoidmain(String[]args){
//TODOAuto-generatedmethodstub
newmyserver2();
}
}
1.4客户端
packagetest;
importjava.io.BufferedReader;
importjava.io.InputStreamReader;
importjava.io.PrintWriter;
.Socket;
publicclassmyclient2{
publicmyclient2(){
try{
//连接服务器端
Sockets=newSocket("127.0.0.1",9999);
PrintWriterpw=newPrintWriter(s.getOutputStream(),true);
InputStreamReaderisr=newInputStreamReader(System.in);
BufferedReaderbr=newBufferedReader(isr);
InputStreamReaderisr2=newInputStreamReader(s.getInputStream());
BufferedReaderbr2=newBufferedReader(isr2);
while(true){
System.out.println("请输入您要对服务器要说的话:");
//客户端先从控制台接受
Stringinfo=br.readLine();
pw.println(info);
if(info.equals("bye")){
System.out.println("通话结束！");
s.close();
break;
}
//接受从服务器发来的信息
Stringres=br2.readLine();
System.out.println("服务器端："+res);
}
}catch(Exceptione){
//TODO:handleexception
}
}
publicstaticvoidmain(String[]args){
//TODOAuto-generatedmethodstub
newmyclient2();
}
}
2.全双工
全双工：全双工(Full Duplex)是通讯传输的一个术语。通信允许数据在两个方向上同时传输，它在能力上相当于两个单工通信方式的结合。全双工指可以同时(瞬时)进行信号的双向传输(A→B且B→A)。指A→B的同时B→A，是瞬时同步的。
2.1工程目录结构：
/**
* 服务器端
*/
package com.test;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import .ServerSocket;
import .Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
public class myserver3 extends JFrame implements ActionListener, KeyListener {
PrintWriter pw=null;
JTextArea jt_aArea=new JTextArea();
JTextField jTextField=new JTextField(10);
JButton btn_send=new JButton("发送");
JPanel jp1=new JPanel();
JScrollPane jsp=new JScrollPane(jt_aArea);
public myserver3 () {
jp1.add(jTextField);
jp1.add(btn_send);
btn_send.addActionListener(this);
jTextField.addKeyListener(this);
this.add(jsp,"Center");
this.add(jp1,"South");
this.setTitle("简易服务器端");
this.setSize(300, 300);
this.setVisible(true);
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
try {
//服务器监听
ServerSocket ss=new ServerSocket(9999);
//等待客户端连接
Socket s=ss.accept();
InputStreamReader isr=new InputStreamReader(s.getInputStream());
BufferedReader br=new BufferedReader(isr);
pw=new PrintWriter(s.getOutputStream(),true);
//读取从客户端发送来的信息
while(true){
String info =br.readLine();
jt_aArea.append("客户端："+info+"\r\n");
}
} catch (Exception e) {
// TODO: handle exception
}
}
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==jTextField){
//System.out.println(e.getKeyCode());
if(e.getKeyCode()==KeyEvent.VK_ENTER){
String info=jTextField.getText();
jt_aArea.append("服务端："+info+"\r\n");
pw.println(info);
//清空内存
jTextField.setText("");
}
}
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
}
public void actionPerformed(ActionEvent arg) {
//如果用户按下发送信息按钮
if(arg.getSource()==btn_send){
String info=jTextField.getText();
jt_aArea.append("服务器："+info+"\r\n");
pw.println(info);
//清空内存
jTextField.setText("");
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new myserver3();
}
}
///
客户端：
package com.test;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import .Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
public class myclient3 extends JFrame implements ActionListener, KeyListener{
JTextArea jt_aArea=new JTextArea();
JTextField jTextField=new JTextField(10);
JButton btn_send=new JButton("发送");
PrintWriter pw=null;
JPanel jp1=new JPanel();
JScrollPane jsp=new JScrollPane(jt_aArea);
public myclient3 () {
jp1.add(jTextField);
jp1.add(btn_send);
btn_send.addActionListener(this);
jTextField.addKeyListener(this);
this.add(jsp,"Center");
this.add(jp1,"South");
this.setTitle("简易客户端");
this.setSize(300, 300);
this.setVisible(true);
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
try {
Socket s=new Socket("127.0.0.1",9999);
InputStreamReader isr=new InputStreamReader(s.getInputStream());
BufferedReader br=new BufferedReader(isr);
pw=new PrintWriter(s.getOutputStream(),true);
while(true){
//不停的读取
String info=br.readLine();
jt_aArea.append("服务器端："+info+"\r\n");//换行
//jt_aArea.setText(info);
}
} catch (Exception e) {
// TODO: handle exception
}
}
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==jTextField){
//System.out.println(e.getKeyCode());
if(e.getKeyCode()==KeyEvent.VK_ENTER){
String info=jTextField.getText();
jt_aArea.append("客户端："+info+"\r\n");
pw.println(info);
//清空内存
jTextField.setText("");
}
}
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
}
public void actionPerformed(ActionEvent arg) {
//如果用户按下发送信息按钮
if(arg.getSource()==btn_send){
String info=jTextField.getText();
jt_aArea.append("客户端："+info+"\r\n");
pw.println(info);
//清空内存
jTextField.setText("");
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new myclient3();
}
}
先启动服务端，在启动客户端
运行效果：
