listenrs.java

很齐全通讯录

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.*;
public class ListenRS extends MIDlet implements CommandListener{
	private Command exitCmd, addCmd, delCmd, setCmd, getCmd;
	private Display display;
	private RecordStore rs;		// 定义记录存储rs
	private TextBox showMsg;	// 用于显示操作结果信息
	private String msg = "";	// 存放用于文本框显示的信息
	public ListenRS() {
		display = Display.getDisplay(this);
		showMsg = new TextBox("操作信息:", null, 512, TextField.ANY);
		exitCmd =new Command("退出",Command.EXIT,1);
		addCmd =new Command("添加记录",Command.SCREEN,1);
		delCmd =new Command("删除记录",Command.SCREEN,1);
		setCmd =new Command("修改记录",Command.SCREEN,1);
		getCmd =new Command("浏览记录",Command.SCREEN,1);
		showMsg.addCommand(exitCmd);
		showMsg.addCommand(addCmd);
		showMsg.addCommand(delCmd);
		showMsg.addCommand(setCmd);
		showMsg.addCommand(getCmd);
		showMsg.setCommandListener(this);
	}
	public void startApp(){
		if (!OpenRS("tempRS"))
			msg = "记录存储tempRS打开失败";
		else
			msg = "记录存储tempRS打开成功";
		showMsg.setString(msg);
 		display.setCurrent(showMsg);
	 }
	public void pauseApp() { }
	public void destroyApp(boolean unconditional) {
		if (CloseRS())
			System.out.println("记录存储tempRS关闭成功");
		else
			System.out.println("记录存储tempRS关闭失败");
		if (DeleteRS("tempRS"))
			System.out.println("记录存储tempRS删除成功");
		else
			System.out.println("记录存储tempRS删除失败");
	}
	public void commandAction(Command c,Displayable d) {
		int recId;
		if (c == exitCmd) {
			destroyApp(false);
			notifyDestroyed();
		}
		else if (c == addCmd) {
			if ((recId = AddRec()) != -1)
				msg = "记录添加成功,记录号为 " + recId;
			else
				msg = "记录添加失败";
			showMsg.setString(msg);
		}
		else if (c == delCmd) {
			if ((recId = DelRec()) != -1)
				msg = "记录删除成功,记录号为 " + recId;
			else
				msg = "记录删除失败";
			showMsg.setString(msg);
		}
		else if (c == setCmd) {
			if ((recId = SetRec()) != -1)
				msg = "记录修改成功,记录号为 " + recId;
			else
				msg = "记录修改失败";
			showMsg.setString(msg);
		}
		else if (c == getCmd) {
			msg = GetRec();
			showMsg.setString(msg);
		}
	}
	// 增加记录,返回所增加记录的记录号，返回-1表示出错
	public int AddRec() {
		int recID = -1;
		try {
			int id = rs.getNextRecordID();
			String rec = "Data with RecordID " + id;
			byte [] data = rec.getBytes();
			recID = rs.addRecord(data, 0, data.length);
		}
		catch (RecordStoreException e) { }
		return recID ;
	}
	// 删除记录，返回所删除记录的记录号，返回-1表示出错
	public int DelRec() {
		try {
			RecordEnumeration re = rs.enumerateRecords(null, null, false);
			if (re.hasNextElement()) {
				int id = re.nextRecordId();
				rs.deleteRecord(id);
				return id;
			}
		}
		catch (RecordStoreException e) { }
		return -1;
	}
	// 修改记录，返回所修改记录的记录号，返回-1表示出错
	public int SetRec() {
		try {
			RecordEnumeration re = rs.enumerateRecords(null, null, false);
			if (re.hasNextElement()) {
				int id = re.nextRecordId();
				String rec = "Modified Data with RecordID " + id;
				byte [] data = rec.getBytes();
				rs.setRecord(id, data, 0, data.length);
				return id;
			}
		}
		catch (RecordStoreException e) { }
		return -1;
	}
	// 浏览记录存储中所有记录
	public String GetRec() {
		String message = null;
		try {
			RecordEnumeration re = rs.enumerateRecords(null, null, false);
			int num = re.numRecords();
			message = "记录存储中共有" + num + "条记录:";
			byte [] data = null;
			int count = 0;
			while(re.hasNextElement()){
				count ++;
				data = re.nextRecord();
				message += "\n第 " + count + " 条记录：";
				message +=	"\n" + new String(data);
			}
		}
		catch (RecordStoreException e) {
			message = "记录读取失败!";
		}
		return message;
	}
	// 打开（创建）记录存储
	public boolean OpenRS(String rsName) {
		try {
			rs = RecordStore.openRecordStore(rsName, true);
			// 注册记录监听器
			rs.addRecordListener(new MyRecordListener());
			return true;
		}
		catch(RecordStoreException e) { }
		return false;
	}
	// 关闭记录存储
	public boolean CloseRS() {
		if(rs != null) {
			try {
				rs.closeRecordStore();
				rs = null;
				return true;
			}
			catch(RecordStoreException e) { }
		}
		return false;
	}
	// 删除记录存储
	public boolean DeleteRS(String rsName) {
		try {
			RecordStore.deleteRecordStore(rsName);
			return true;
		}
		catch(RecordStoreException e) { }
		return false;
	}
}
// 定义监听器，监听记录的添加、删除和修改事件
class MyRecordListener implements RecordListener {
	// 响应记录添加事件
	public void recordAdded(RecordStore recordStore,int recordID){
		try{
			String rsName = recordStore.getName();
			System.out.println("在记录存储" + rsName + 
				"中添加记录，记录号为"+recordID);
		}			
		catch(RecordStoreException e){ }
	}
	// 响应记录修改事件
	public void recordChanged(RecordStore recordStore,int recordID){
		try{
			String rsName = recordStore.getName();
			System.out.println("在记录存储" + rsName + 
				"中修改记录，记录号为"+recordID);
		}			
		catch(RecordStoreException e){ }
	}
	// 响应记录删除事件
	public void recordDeleted(RecordStore recordStore,int recordID){
		try{
			String rsName = recordStore.getName();
			System.out.println("在记录存储" + rsName + 
				"中删除记录，记录号为"+recordID);
		}			
		catch(RecordStoreException e){ }
	}
};