midlet4.java

这是郭克华老师的J2ME视频的源代码

package prj16_1;

import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.rms.RecordComparator;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordFilter;
import javax.microedition.rms.RecordStore;

public class MIDlet4 extends MIDlet implements RecordFilter,RecordComparator{

	protected void startApp() throws MIDletStateChangeException {
		RecordStore rs = null;
		try{
			rs = RecordStore.openRecordStore("RS1", true);
			System.out.println(rs.getSizeAvailable());//记录集可用空间
			rs.addRecord("567".getBytes(), 0, "567".getBytes().length);
			rs.addRecord("125".getBytes(), 0, "125".getBytes().length);
			rs.addRecord("342".getBytes(), 0, "342".getBytes().length);
			rs.addRecord("78".getBytes(), 0, "78".getBytes().length);
			rs.addRecord("92".getBytes(), 0, "92".getBytes().length);
			
			RecordEnumeration re = rs.enumerateRecords(this, this, false);
			while(re.hasNextElement()){
				System.out.println(new String(re.nextRecord()));
			}			
			
		}catch(Exception ex){
			ex.printStackTrace();
		}
		finally{
			try{
				rs.closeRecordStore();
			}catch(Exception ex){}
		}

	}
	
	public int compare(byte[] rec1,byte[] rec2){
		String  str1 = new String(rec1);
		String  str2 = new String(rec2);
		int num1 = Integer.parseInt(str1);
		int num2 = Integer.parseInt(str2);
		if(num1>num2){
			return RecordComparator.FOLLOWS;
		}
		else if(num1<num2){
			return RecordComparator.PRECEDES;
		}
		return RecordComparator.EQUIVALENT;
	}	
	
	public boolean matches(byte[] candidate){
		String  str = new String(candidate);
		int num = Integer.parseInt(str);
		if(num > 100){
			return true;
		}
		return false;
	}
	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
		// TODO Auto-generated method stub

	}

	protected void pauseApp() {
		// TODO Auto-generated method stub

	}



}