rms_midlet.java

小型的数据管理系统RecordStore 可添加、修改

import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.rms.*;
import java.io.*;


public class RMS_MIDlet extends MIDlet {

	Display display = null;
	RecordStore rs = null;
	Form form = null;
	
	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
		// TODO Auto-generated method stub

	}

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

	}

	protected void startApp() throws MIDletStateChangeException {
		// TODO Auto-generated method stub
		display = Display.getDisplay(this);
		form = new Form("记录仓库");
		
		ByteArrayOutputStream baos = new ByteArrayOutputStream( );//数组输出流
		DataOutputStream os = new DataOutputStream(baos);//输出流

		try
		{
			os.writeUTF("Player1");
			os.writeInt(100);
			rs = RecordStore.openRecordStore("TOP", true);//创建一个记录仓库
			RecordStore.openRecordStore("TOP1", true);
			RecordStore.openRecordStore("TOP2", true);
			form.append(rs.getName()+"\n");
			form.append(rs.getLastModified()+"\n");
			form.append(rs.getNumRecords()+"\n");
			form.append(rs.getSize()+"\n");
			form.append(rs.getSizeAvailable()+"\n");
			form.append(rs.getVersion()+"\n");
			//向记录仓库里面添加一条记录
			System.out.println(rs.addRecord(baos.toByteArray(), 0, baos.toByteArray().length));
			
			ByteArrayInputStream bis = new ByteArrayInputStream(rs.getRecord(1));//数组输入流
			DataInputStream is = new DataInputStream(bis);//输入流
			form.append("name:"+is.readUTF()+"\n");
			form.append("score:"+is.readInt()+"\n");
			
			baos.reset();
			os.writeUTF("Player1");
			os.writeInt(1000);
			rs.setRecord(1, baos.toByteArray(), 0, baos.toByteArray().length);
			DataInputStream is1 = new DataInputStream(new ByteArrayInputStream(rs.getRecord(1)));
			form.append(is1.readUTF()+"\n");
			form.append(""+is1.readInt());
			
		}catch(Exception e)
		{
			e.printStackTrace();
		}
		String s[] = RecordStore.listRecordStores();
		for(int i = 0;i<s.length;i++)
		{
			if(s[i].equals("TOP"))
			{
				System.out.println("找到了 TOP");
			}else{
				System.out.println(s[i]);
			}
		}
		display.setCurrent(form);
	}

}