getrecordmidlet.java

java移动通信程序设计

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.*;
// A first MIDlet with simple text and a few commands.
public class getRecordMIDlet extends MIDlet
implements CommandListener {
  private Command exitCommand;
    //The display for this MIDlet
  private Display display;

  public getRecordMIDlet() {
    display = Display.getDisplay(this);
    exitCommand = new Command("离开", Command.STOP, 1);
   }

  // Start the MIDlet by creating the TextBox and
  // associating the exit command and listener.
  public void startApp() {
	TextBox aTextBox = new TextBox("主画面",null,256,TextField.ANY);

	RecordStore rs = null;
	byte[] nameEmail=null;
	boolean existingOrNot = false;
	boolean OK = true;

	existingOrNot = existing("aRS");
	if(existingOrNot){
	   try{
		rs = RecordStore.openRecordStore("aRS",false);
            }
            catch(Exception e){
		OK = false;
	   }
	   finally{
		 if(OK){
			 aTextBox.setString("aRS已存在并且已打开");
	          }
	          else{
			aTextBox.setString("aRS已存在但无法打开");
	          }
         }
      }
    else{
	   try{
		   rs = RecordStore.openRecordStore("aRS",true);
	    }
        catch(Exception e){
		   OK = false;
	    }
	    finally{
		   if(OK){
	    	aTextBox.setString("aRS虽未存在，但已创建并完成打开的操作!");
		   }
		   else{
	      	aTextBox.setString("aRS虽未存在，但无法创建，打开文件失败!");
		   }
	    }
	}

    if(OK)
       try{
	    	int number = rs.getNumRecords();
	    	String record="";
	    	String result="共有" + number + "笔记录\n";

	    	int position=0;

            for(int i =1;i< rs.getNextRecordID();i++){
               record = new String(rs.getRecord(i));
               position = record.indexOf('=');

               if(position !=-1){
					result+="name->" + record.substring(0,position) + "\n" +
	                          "E-mail:" + record.substring(position+1,record.length()) +"\n";
	                System.out.println(result);
		        }
		    }
			aTextBox.setString(result);
		  }
	   catch(Exception e){
		   aTextBox.setString("获取记录的操作失败"  );
		   try{
				rs.closeRecordStore();
				System.out.println("1.Closed.");
		        RecordStore.deleteRecordStore("aRS");
				System.out.println("delete OK");
			}
			catch(Exception x){
            }
	   }

    if(OK)
    	try{
		   rs.closeRecordStore();
		   System.out.println("2.Closed.");
	//	   RecordStore.deleteRecordStore("aRS");
	//	   System.out.println("delete OK");
	    }
	   catch(Exception e){
       }

    aTextBox.addCommand(exitCommand);
    aTextBox.setCommandListener(this);
    display.setCurrent(aTextBox);
  }

  // Pause is a no-op because there are no background
  // activities or record stores to be closed.
  public void pauseApp() { }

  // Destroy must cleanup everything not handled
  // by the garbage collector.
  // In this case there is nothing to cleanup.
  public void destroyApp(boolean unconditional) { }

  public boolean existing(String recordStoreName) {
    boolean existingOrNot = false;
    RecordStore rs = null;
    if(recordStoreName.length() > 32) return false;
      try{
	      rs = RecordStore.openRecordStore(recordStoreName,false);
      }
      catch(RecordStoreNotFoundException e){
	      existingOrNot = false;
      }
      catch(Exception e){
      }
      finally{
	    try{
	       rs.closeRecordStore();
	    }
	    catch(Exception e){
	    }
      }
     return existingOrNot;
  }

  public void commandAction(Command c, Displayable s) {
     destroyApp(false);
      notifyDestroyed();
  }
}