package chat;

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

public class Chat1
{
	private JFrame frame;
	private Container contentPane;
	private JTextField tf1;
	private JTextArea ta,tb;
	private JButton btnCon,btnSend,btnExit;
	private JRadioButton rb1;
	private JRadioButton rb2;
	private String strbuf="";
	private DatagramSocket serverSocket,clientSocket;

	public Chat1()
	{
		frame=new JFrame("聊天室");
		frame.setSize(460,460);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setResizable(false);
		contentPane=frame.getContentPane();
		initGUI();
	}	

	public void initGUI()
	{
		contentPane.setLayout(new BorderLayout());
		JPanel panel1=new JPanel(new GridLayout(3,1));

		JPanel p11=new JPanel(new FlowLayout(FlowLayout.LEFT));
		p11.add(new JLabel("UDP連接程序"));

		JPanel p12=new JPanel(new FlowLayout(FlowLayout.LEFT));
		rb1=new JRadioButton("服務器端");
		rb2=new JRadioButton("客戶端");
		ButtonGroup bg=new ButtonGroup();
		bg.add(rb1);
		bg.add(rb2);
		p12.add(rb1);
		p12.add(rb2);
		p12.add(new JLabel("連接狀態"));
		tf1=new JTextField(20);
		tf1.setEditable(false);
		p12.add(tf1);

		panel1.add(p11);
		panel1.add(p12);

		contentPane.add(panel1,BorderLayout.NORTH);

		JPanel panel2=new JPanel(new FlowLayout(FlowLayout.LEFT));
		panel2.add(new JLabel("收到的信息"));
		ta=new JTextArea(10,30);
		ta.setEditable(false);
		panel2.add(ta);
		int v = ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;
		int h = ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED;
		JScrollPane pane=new JScrollPane(ta,v,h);
		panel2.add(pane);
		contentPane.add(panel2,BorderLayout.CENTER);

		JPanel panel3=new JPanel(new GridLayout(2,1));

		JPanel p31=new JPanel(new FlowLayout(FlowLayout.LEFT));
		p31.add(new JLabel("發送信息"));
		tb=new JTextArea(3,30);
		
		p31.add(tb);

		JPanel p32=new JPanel(new FlowLayout());
		btnCon=new JButton("連接");
		btnSend=new JButton("發送");
		btnExit=new JButton("關閉連接");
		btnSend.setEnabled(false);
		btnExit.setEnabled(false);
		p32.add(btnCon);
		p32.add(btnSend);
		p32.add(btnExit);

		panel3.add(p31);
		panel3.add(p32);
		contentPane.add(panel3,BorderLayout.SOUTH);	

		ActionListener listener =new ActionListener(){
			public void actionPerformed(ActionEvent e)
			{
				//服務器端或客戶端的連接
				if(e.getSource()==btnCon)
				{	
						if(rb1.isSelected()==false&&rb2.isSelected()==false)
{
	tf1.setText("請選擇客戶端或服務器端!");
	return;
	}
					try
					{
						if(rb1.isSelected()==true)
						{
							tb.setText("");
							rb1.setEnabled(false);
							rb2.setEnabled(false);
							Server server=new Server();
						}
						if(rb2.isSelected()==true)
						{
							rb1.setEnabled(false);
							rb2.setEnabled(false);
							tb.setText("");
							Client client=new Client();
						}
					}catch(Exception e1)
					{
						tf1.setText("連接錯誤!");
					}
				}

				//服務器端或客戶端信息的發送
	if(e.getSource()==btnSend)
	{
			try
			{
			strbuf=tb.getText();
			if(strbuf.length()>0)
			{
			ta.append(strbuf+"\n");
			}
			tb.setText("");
		byte [] buffer=new byte[strbuf.length()];
		buffer=strbuf.getBytes();					DatagramPacket packet;
		if(rb1.isSelected()==true)
		{
							packet=new DatagramPacket(buffer,buffer.length,new InetSocketAddress("localhost",902));
							serverSocket.send(packet);
						}
						if(rb2.isSelected()==true)
						{
							packet=new DatagramPacket(buffer,buffer.length,new InetSocketAddress("localhost",901));
							clientSocket.send(packet);
						}
				
					}catch(Exception e1)
					{
						e1.printStackTrace();
					}
				}
				//服務器端或客戶端的斷開
				if(e.getSource()==btnExit)
				{
					try
					{
						if(rb1.isSelected()==true)
						{
							serverSocket.close();
							Thread.currentThread().interrupt();
						}
						if(rb2.isSelected()==true)
						{
							clientSocket.close();
							Thread.currentThread().interrupt();
						}
						tf1.setText("離線");
						btnCon.setEnabled(true);
						btnSend.setEnabled(false);			
						btnExit.setEnabled(false);
					}catch(Exception e1)
					{
						tf1.setText("關閉時發生錯誤!");
					}
					

				}
			}
		};

		btnCon.addActionListener(listener);
		btnSend.addActionListener(listener);
		btnExit.addActionListener(listener);
		
	}
//實現服務器端信息接收的成員內部類
	public class Server implements Runnable
	{
		public Server()
		{
			(new Thread(this)).start();
		}


		public void run()
		{
			String s;
			try
			{
				btnCon.setEnabled(false);
				serverSocket=new DatagramSocket(901);
				ta.setText(InetAddress.getLocalHost().getHostName()+"port:901"+"\n");
				tf1.setText("連接中");
				btnSend.setEnabled(true);
				btnExit.setEnabled(true);

				while(true)
				{
					//接收
					byte [] buffer=new byte[256];
					DatagramPacket packet=new DatagramPacket(buffer,buffer.length);
					serverSocket.receive(packet);
					s=new String(packet.getData());
					s=s.trim();
					if(s.length()>0)
					{
						ta.append("Client:       "+s+"\n");
					}

					
				}

			}catch(Exception e1)
			{
				e1.printStackTrace();
			}
			
		}

	}
//實現客戶端信息接收的多線程內部類
	public class Client implements Runnable
	{
		public Client()
		{
			(new Thread(this)).start();
		}

		public void run()
		{
			DatagramPacket packet;
			String s;
			try
			{
				btnCon.setEnabled(false);
				clientSocket=new DatagramSocket(902);
				ta.setText(InetAddress.getLocalHost().getHostName()+"port:902"+"\n");
				tf1.setText("連接中");
				btnSend.setEnabled(true);
				btnExit.setEnabled(true);
				while(true)
				{
					//接收
					byte [] buffer=new byte[256];
					packet=new DatagramPacket(buffer,buffer.length);
					clientSocket.receive(packet);
					s=new String(packet.getData());
					s=s.trim();
					if(s.length()>0)
					{
						ta.append("server:     "+s+"\n");
					}
					
					
				}
						
			}catch(Exception e)
			{
				e.printStackTrace();
			}
		}
	} 

	public void go()
	{
		frame.setVisible(true);
	}

	public static void main(String args[])
	{
		(new Chat1()).go();
	}
}