imageloadermidlet.java

一组http交互程序 ConnectHttpMIDlet HttpCookieMIDlet.java HttpGETMIDlet.java HttpHEADMIDlet.java Ht

import java.io.*;

import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class ImageLoaderMIDlet extends MIDlet {
  private Item mItem;//联机成功时作为ImageItem，失败时作为StringItem

  public void startApp() {
    final Display display = Display.getDisplay(this);

    if (mItem == null) {
      Form mainForm = new Form("载入中...");
      display.setCurrent(mainForm);

      // Create the Form that will show the Image.
      final Form imageForm = new Form("图片");
      imageForm.addCommand(new Command("离开", Command.EXIT, 0));
      imageForm.setCommandListener(new CommandListener() {
        public void commandAction(Command c, Displayable s) {
          notifyDestroyed();
        }
      });

      // Do network loading in a separate thread.
      Thread t = new Thread() {
        public void run() {
          try {
            String URL = "http://localhost/JIDCA/Duke.png";
            Image image = loadImage(URL);
            mItem = new ImageItem(null, image, 0, null);
          }
          catch (IOException ioe) {
            mItem = new StringItem(null, ioe.toString());
          }
          imageForm.append(mItem);
          display.setCurrent(imageForm);
        }
      };
      t.start();
    }

  }

  public Image loadImage(String url) throws IOException {
    HttpConnection hpc = null;
    DataInputStream dis = null;
    try {
	  hpc = (HttpConnection)Connector.open(url);
      int length = (int)hpc.getLength();
      byte[] data = new byte[length];
      dis = new DataInputStream(hpc.openInputStream());
      dis.readFully(data);
      return Image.createImage(data, 0, data.length);
    }
    finally {
      if(hpc != null) hpc.close();
      if(dis != null) dis.close();
    }
  }

  public void pauseApp() {}

  public void destroyApp(boolean unconditional) {}
}