为什么System.out.println(Aa.readLine() 输出的是false ？

Question

package l;//客户端import java.awt.BorderLayout;import java.awt.Frame;import java.awt.TextArea;import java.awt.TextField;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.KeyAdapter;import java.awt.event.KeyEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.io.PrintStream;import java.io.PrintWriter;import java.net.Socket;import java.net.UnknownHostException;import java.security.Key;public class Q extends Frame{PrintStream L;Q F;// BufferedWriter L;Frame s=new Frame("客户端");TextArea s1=new TextArea ();TextField s2=new TextField();public Q(){s.setSize(500,500);s.setVisible(true);s.add(s1,BorderLayout.CENTER);s.add(s2,BorderLayout.SOUTH);s.pack();s.addWindowListener(new WindowAdapter(){@Overridepublic void windowClosing(WindowEvent e) {// TODO Auto-generated method stubsuper.windowClosing(e);System.exit(0);}});s2.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) {L.print(s2.getText());s1.append(s2.getText()+"\n");s2.setText("");}});}public void aa(){try {s1.append("等待与服务器连接"+"\n");Socket s=new Socket("192.168.1.105",9080);OutputStream S=s.getOutputStream();// OutputStreamWriter SS=new OutputStreamWriter(S);L=new PrintStream(S);// L=new BufferedWriter(SS);s1.append("服务器连接成功"+"\n");} catch (UnknownHostException e) {// TODO Auto-generated catch blocks1.append("服务器连接失败"+"\n");} catch (IOException e) {// TODO Auto-generated catch blocks1.append("服务器连接失败"+"\n");}}public static void main(String args[]){Q F=new Q();F.aa();// F.pack();}}

Answer 1

import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;

public class Server extends JFrame
{
private JTextArea jta=new JTextArea();
public static void main(String[] args)
{ new Server(); }
public Server()
{
setLayout(new BorderLayout());
add(new JScrollPane(jta),BorderLayout.CENTER);

setTitle("Server");
setSize(500,300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);

try
{
ServerSocket serverSocket=new ServerSocket(8000);
jta.append("Server started at "+new Date()+'\n');

Socket socket=serverSocket.accept();

DataInputStream inputFromClient=new DataInputStream(socket.getInputStream());
DataOutputStream outputToClient=new DataOutputStream(socket.getOutputStream());

while(true)
{
double radius=inputFromClient.readDouble();
double area=radius*radius*Math.PI;
outputToClient.writeDouble(area);

jta.append("Radius received from client: "+radius+'\n');
jta.append("Area found: "+area+'\n');
}
}
catch(IOException ex)
{ System.err.println(ex); }
}
}
客户端代码如下：
import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Client extends JFrame
{
private JTextField jtf=new JTextField();
private JTextArea jta=new JTextArea();
private DataOutputStream toServer;
private DataInputStream fromServer;

public static void main(String args[])
{
new Client();
}
public Client()
{
JPanel p=new JPanel();
p.setLayout(new BorderLayout());
p.add(new JLabel("Enter radius:"),BorderLayout.WEST);
p.add(jtf,BorderLayout.CENTER);
jtf.setHorizontalAlignment(JTextField.RIGHT);

setLayout(new BorderLayout());
add(p,BorderLayout.NORTH);
add(new JScrollPane(jta),BorderLayout.CENTER);

jtf.addActionListener(new ButtonListener());

setTitle("Client");
setSize(500,300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);

try
{
Socket socket=new Socket("dzy_3347ff08bc0.whpu.edu.cn",8000);
fromServer=new DataInputStream(socket.getInputStream());
toServer=new DataOutputStream(socket.getOutputStream());
}
catch(IOException ex)
{ System.out.println(ex); }
}

private class ButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
try
{
double radius=Double.parseDouble(jtf.getText().trim());
toServer.writeDouble(radius);
toServer.flush();

double area=fromServer.readDouble();

jta.append("Radius is "+radius+"\n");
jta.append("Area received from the server is "+area+'\n');
}
catch(IOException ex)
{ System.out.println(ex); }
}
}
}