rsinfor.java

jBuilderX无线应用开发源代码

import javax.microedition.midlet.*;
import javax.microedition.rms.*;
import javax.microedition.lcdui.*;
import java.util.*;

public class RSInfor extends MIDlet	implements CommandListener{
	
	private	RecordStore	rs;       	//声明一个RecordStore对象
	private	Display	display;     
	private	TextBox	t;
	private	Command	backCommand;
	private List startMenu;            	//选择菜单
	
	private static final String[] startMenuStr = {
	    "Version",                		//存储集版本
	    "Size",                   	//存储集大小
	    "Avalaible Size",        		//剩余空间
	    "Record Number",          	//记录数
	    "Last Modified",          		//最后修改日期
	    "Next Record",            		//下一个记录ID
	    "RS Name",                	//存储集名称
	};
		
	public RSInfor () {
		//将rs初始化为null
		rs = null;
		backCommand	= new Command("Back", Command.BACK,	1);
		startMenu = new List("select one", List.IMPLICIT, startMenuStr, null);
		startMenu.setCommandListener(this);
		display	= Display.getDisplay(this);
	}
	
	public void	startApp() {
		display.setCurrent(startMenu);
	}
		
	public void	pauseApp(){
	}
	
	public void	destroyApp(boolean unconditional){
	    startMenu = null;
	    t = null;
	    backCommand = null;
	}
	
	public void  commandAction(Command c, Displayable s)	{
		if(s == startMenu  &&  c == List.SELECT_COMMAND) {
			int selectedNum = startMenu.getSelectedIndex();
			t = new TextBox(null, "", 256, 0);
			t.addCommand(backCommand);
			t.setCommandListener(this);
			
			try {
    		    //打开记录存储myRecordStore
    		    rs = RecordStore.openRecordStore("myRecordStore", false);
    		}catch(Exception e){
              //捕获异常RecordStoreException  		 
    		    System.out.println("Error: " + e.getMessage());
    		}
    		
    		try {
        		if(selectedNum == 0) {//存储集版本
        		    t.setString("Version:" + Integer.toString(rs.getVersion()));
        		}
        		else if(selectedNum == 1) {//存储集大小
        		    t.setString("Size:" + Integer.toString(rs.getSize()));
        		}
        		else if(selectedNum == 2) {//剩余空间
        		    t.setString("Available Size:" + Integer.toString(rs.getSizeAvailable()));
        		}
        		else if(selectedNum == 3) {//记录数
        		    t.setString("Records Number:" + Integer.toString(rs.getNumRecords()));
        		}
        		else if(selectedNum == 4) {//最后修改日期
        		    long lastModifiedTime = rs.getLastModified();
        		    Calendar cal = Calendar.getInstance();
        		    cal.setTime(new Date(lastModifiedTime));
        		    t.setString("Last Modified:" + cal.toString());
        		}
        		else if(selectedNum == 5) {//下一个记录ID
        		    t.setString("Next Record ID:" + Integer.toString(rs.getNextRecordID()));
        		}
        		else if(selectedNum == 6) {//存储集名称
        		    t.setString("Suite Name:" + rs.getName());
        		}
        		else {
        		    System.out.println("Error selected number. ");
        		}
        	}catch(Exception e){
        	    System.out.println("Error: " + e.getMessage());
        	}
        	display.setCurrent(t); 
        	
        	//关闭记录存储集
        	try{
    			rs.closeRecordStore();
    		}catch(Exception e){
    		    System.out.println("Error: " + e.getMessage());
    		}   		
    	}
    	else if(c == backCommand){
    	    //返回选择菜单
    	    display.setCurrent(startMenu);
    	}
    }
}