listing 15-1.java

关于j2me的midlet事例源码, 能帮助你晋级!

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.*;
import javax.microedition.io.*;
import java.util.*;
public class HttpExample extends MIDlet implements CommandListener 
{
  private Command exit, start;
  private Display display;
  private Form form;
  private StringItem stars;
  public HttpExample () 
  {
    display = Display.getDisplay(this);
    exit = new Command("Exit", Command.EXIT, 1);
    start = new Command("Start", Command.EXIT, 1);
    form = new Form("Customer Ranking");
    form.addCommand(exit);
    form.addCommand(start);
    form.setCommandListener(this);
  }
  public void startApp() throws MIDletStateChangeException 
  {
    display.setCurrent(form);
  }
  public void pauseApp() 
  {
  }
  public void destroyApp(boolean unconditional) 
  {
  }
  public void commandAction(Command command, Displayable displayable) 
  {
    if (command == exit) 
    {
      destroyApp(false);
      notifyDestroyed();
    }
    else if (command == start) 
    {
      StreamConnection connection = null;
      InputStream in = null;
      StringBuffer buffer = new StringBuffer();
       try 
         {
        connection = (StreamConnection)
Connector.open(
           "http://www.amazon.com/exec/obidos/tg/detail/-/007222472X");
       in = connection.openInputStream();
       int ch;
       while ((ch = in.read()) != -1) 
       {
         if (ch != '\n') 
         {
           buffer.append((char)ch);
         }
         else 
         {
           String line = new String (buffer.toString());
           if(line.equals("out of 5 stars"))
           {
              int position = line.indexOf("alt=");
              Alert alert = new Alert(
               "Rating", line.substring(position + 5, position + 8), null, null);
              alert.setTimeout(Alert.FOREVER);
              alert.setType(AlertType.ERROR);
              display.setCurrent(alert);      
            }
            buffer = new StringBuffer();
          }
        }  
       }
       catch (IOException error) 
       {
        Alert alert = new Alert("Error", "Cannot connect", null, null);
        alert.setTimeout(Alert.FOREVER);
        alert.setType(AlertType.ERROR);
        display.setCurrent(alert);      
      }
    }
  }
 }