users.java

很齐全通讯录

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.*;
import java.util.*;
public class UseRS extends MIDlet implements CommandListener{
    private Command exitCommand, createCmd, delCmd, useCmd;
    private Display display;
	private RecordStore rs; // 记录存储rs在打开、关闭操作中使用
	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 UseRS() {
    	display = Display.getDisplay(this);
		showMsg = new TextBox("操作信息:", null, 200, TextField.ANY);
        exitCommand =new Command("退出",Command.EXIT,1);
        createCmd =new Command("建立",Command.SCREEN,1);
        useCmd =new Command("使用",Command.SCREEN,1);
        delCmd =new Command("删除",Command.SCREEN,1);
        showMsg.addCommand(exitCommand);
        showMsg.addCommand(createCmd);
        showMsg.addCommand(useCmd);
        showMsg.addCommand(delCmd);
        showMsg.setCommandListener(this);
    }
    public void startApp(){
		// 显示当前MIDlet套件中已经建立的记录存储名称
		msg = "套件中已经建立的记录存储有: ";
		String [] RSExist = RecordStore.listRecordStores();
		if (RSExist != null) {
			for (int i=0; i<RSExist.length; i++) {
				msg += "\n" + RSExist[i];
			}
		}
		showMsg.setString(msg);	// 更新文本框中显示的内容
 		display.setCurrent(showMsg);
   }
    public void pauseApp() { }
    public void destroyApp(boolean unconditional) { }
    public void commandAction(Command c,Displayable d) {
        if (c == exitCommand) {
            destroyApp(false);
            notifyDestroyed();
        }
        else if (c == createCmd) {
            if (ExistRS("myRS"))
                msg = "记录存储myRS己经存在";
            else if (CreateRS("myRS"))
                msg = "记录存储myRS创建成功";
			else 
                msg = "记录存储myRS创建失败";
        }
        else if(c == delCmd) {
            if (!ExistRS("myRS"))
                msg = "记录存储myRS不存在";
            else if (DeleteRS("myRS"))
                msg = "记录存储myRS删除成功";
			else 
                msg = "记录存储myRS删除失败";
        }
        else if (c == useCmd) {
            if (!ExistRS("myRS"))
                msg = "记录存储myRS不存在";
            else {
				if (OpenRS("myRS")) {
					msg = "记录存储myRS打开成功";
					// 获取打开的记录存储的信息
					try	{
						Date lmt = new Date(rs.getLastModified());
						msg += "\nLastModified = " + lmt.toString();
						msg += "\nName = " + rs.getName();
						msg += "\nVersion = " + rs.getVersion();
						msg += "\nSize = "+ rs.getSize();
						msg += "\nSizeAvailable = " + rs.getSizeAvailable();
					}
					catch (RecordStoreException e)	{ }
				}
				else
					msg = "记录存储myRS打开失败";
				if (CloseRS())
					msg += "\n记录存储myRS关闭成功";
				else
					msg += "\n记录存储myRS关闭失败";
			}
		}
		showMsg.setString(msg);
    }
    // 检测当前套件中记录存储是否存在
    public boolean ExistRS(String rsName) {
		try {
            RecordStore r = RecordStore.openRecordStore(rsName, false);
            r.closeRecordStore();
            r = null;
        }
        // 捕捉到记录存储找不到的异常，表示记录存储不存在
		catch(RecordStoreNotFoundException e1) {
            return false;
        }
        catch(RecordStoreException e2) { }
        return true;
    }
    // 创建记录存储，之前需先检查记录存储是否已经存在
    public boolean CreateRS(String rsName) {
        // 创建一个记录存储
		try {
            RecordStore r = RecordStore.openRecordStore(rsName, true);
            r.closeRecordStore();
            r=null;
            return true;
        }
        catch(RecordStoreException e) { }
        return false;
    }
    // 删除记录存储，之前需先检查记录存储是否已经存在
    public boolean DeleteRS(String rsName) {
        try {
            RecordStore.deleteRecordStore(rsName);
            return true;
        }
        catch(RecordStoreException e) { }
        return false;
    }
	// 打开记录存储
    public boolean OpenRS(String rsName) {
        try {
            rs = RecordStore.openRecordStore(rsName, false);
            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;
    }
}