elementinfoscreen.java

手机游戏设计一书的源代码

package webservice.midlet;

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


public class ElementInfoScreen extends Canvas implements CommandListener {

  String elementName = null;

  public ElementInfoScreen(String elementNumber) {
    this.elementNumber = elementNumber;
    addCommand(new Command("Back", Command.BACK, 1));
    setCommandListener(this);
    new Thread(new HttpConnector()).start();
  }



  private void showElementInfo () {
      repaint();
  }

  /**处理命令事件*/
 public void commandAction(Command command, Displayable displayable) {
   if(command.getCommandType()==command.BACK) {

       ElementNumberScreen clientScreen = new ElementNumberScreen();
       Display.getDisplay(ChemistryMIDlet.chemistryMIDlet).setCurrent(clientScreen);
   }
 }



  class HttpConnector
          implements java.lang.Runnable {

      /**
*  在线程主函数中调用获取化学元素名称方法获取化学元素名称，
*  并调用显示方法进行显示。
*/
      public void run () {
          getElementName();
          showElementInfo ();
      }
  }


 /**
 *  获取元素名称方法
 */
public void getElementName () {
    try {
        HttpConnection connection = (HttpConnection)Connector.open("http://localhost:7001/midp/chemistryservlet?inputpara="+elementNumber);
        InputStream is = null;
        is = connection.openInputStream();
        DataInputStream dis = new DataInputStream(is);
        elementName = dis.readUTF();
        dis.close();
        is.close();
        connection.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}


  public void paint(Graphics g) {

     g.setColor(0xffffff);
     g.fillRect(0,0,getWidth(),getHeight());
     g.setColor(0x000000);
     if (elementNumber != null) {
       g.drawString("元素号 :  " + elementNumber, 0, 20, Font.SIZE_MEDIUM);
     }
     if (elementName != null) {
       g.drawString("元素名称 :  " + elementName, 0, 40, Font.SIZE_MEDIUM);
     }
  }

  private String elementNumber = null;
}