一个applet---servlet通讯的例子---applet文件.txt

收集来的一些java方面的技术

作者：climbeNET
日期：2000-11-6 11:30:03
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;

public class sendapplet extends Applet implements ActionListener 
{
	Label sendlable;
	Label messageInfo;
	Button sendButton;
	TextField sendText;
	TextField messageText;
	URLConnection connect;
	String message;
	URL chatURL;
	public String getAppletInfo()
	{
		return "this is a applet--servlet";
	}
	
	public synchronized void init()
	{
		super.init();
		resize(500,300);
		sendlable=new Label("Please enter Massage");
		messageInfo=new Label("What you hava send:");
		sendText=new TextField(40);
		sendButton=new Button("Send");
		messageText=new TextField(40);
		messageText.setEditable(false);
		//
		
		
		
		
		//
		Panel mainp=new Panel();
		GridBagLayout gbl=new GridBagLayout();
		GridBagConstraints gbc=new GridBagConstraints();
		gbc.weightx=0;
		gbc.weighty=0;
		gbc.gridy=0;
		gbc.gridx=0;
		gbc.gridwidth=10;
		gbc.gridheight=1;
		gbc.anchor=GridBagConstraints.CENTER;
		gbc.fill=GridBagConstraints.NONE;
		mainp.setLayout(gbl);
		gbl.setConstraints(sendlable,gbc);
		mainp.add(sendlable);
		gbc.gridy=1;
		gbc.gridwidth=9;
		gbc.fill=GridBagConstraints.HORIZONTAL;
		gbl.setConstraints(sendText,gbc);
		mainp.add(sendText);
		gbc.gridx=9;
		gbc.gridwidth=1;
		gbc.fill=GridBagConstraints.NONE;
		gbl.setConstraints(sendButton,gbc);
		mainp.add(sendButton);
		gbc.gridx=0;
		gbc.gridy=2;
		gbc.gridwidth=10;
		gbl.setConstraints(messageInfo,gbc);
		mainp.add(messageInfo);
		gbc.gridy=3;
		gbc.weighty=100;
		gbc.gridheight=10;
		gbc.fill=GridBagConstraints.BOTH;
		gbl.setConstraints(messageText,gbc);
		mainp.add(messageText);
		sendButton.addActionListener(this);
		//构造的panel加入到applet中
		setLayout(new BorderLayout());
		add("Center",mainp);
		chatURL=getCodeBase();
	}
	public synchronized void start()
	{
	}
	public synchronized void stop()
	{
	}
	public synchronized void destroy()
	{
	}
	
	//
	private void Send()
	{
		message=sendText.getText();
		sendText.setText("");
		//showStatus("Message send!");
		p("Message send!");
		messageText.setText("message");
		String queryString="/servlet/Receive?message"+URLEncoder.encode(message);
		p("Attemping to send :"+message);
		try{
		    connect=(new URL(chatURL,queryString)).openConnection();
		    showStatus("Open Connection!");
		    connect.setDefaultUseCaches(false);
		    connect.setUseCaches(false);
		    connect.setDoInput(true);
		    connect.setDoOutput(false);
		    connect.connect();
		    p("Make connection to "+connect);
		    showStatus("Open Sream!");
		    DataInputStream in=new DataInputStream(connect.getInputStream());
		    showStatus("reading");
		    message=in.readLine();
		    while(message!=null)
		    {
		    	messageText.setText(message);
		    	message=in.readLine();
		    	
		    }//end while
		   
		   
		
		   
		}//end try
		catch(MalformedURLException e2)
		{
		      System.err.println("Malformedurlexception:"+e2.toString());
		      
		}//end catch
		catch(IOException e1)
		{
		      System.err.println(e1.toString());
		      
		}
		
	}//end Send
	
	public void actionPerformed(ActionEvent e)
	{
	    if(e.getSource()==sendButton)
	    {
	    	Send();
	    
	    }
	
	}
	
	private void p(String debug)
	{   
	     messageText.setText(debug);
	    //System.out.println("app-servlet:"+debug);
	    
	}
		
}