public class RecordStoreUtil {
public RecordStore openARecondStore(String rsname){
    RecordStore rs=null;
    if(rsname.length()>32) return null;
    try{
         rs=RecordStore.openRecordStore(rsname,true);
    }catch(RecordStoreFullException notFoundException){

    }catch(RecordStoreNotFoundException notFoundException){

    }catch(RecordStoreException notFoundException){

    }finally{
        return rs;
    }
}
public RecordStore openARecordStoreExisted(String rsname){
    RecordStore rs=null;
    if(rsname.length()>32)return null;
   try{
         rs=RecordStore.openRecordStore(rsname,false);
    }catch(RecordStoreFullException notFoundException){

    }catch(RecordStoreNotFoundException notFoundException){

    }catch(RecordStoreException notFoundException){

    }finally{
        return rs;
    }
}
 //删除
public static boolean delRecordStore(String rsname){
    //
    if(rsname.length()>32)return false;
    //

   try{
       RecordStore.deleteRecordStore(rsname);

   }catch(Exception e){
       return false;
   }
    return true;
}
//添加
public static int writeString(RecordStore rs,String myString){
    byte[] b=myString.getBytes();
    int id=-1;
    try{
        id=rs.addRecord(b, 0, b.length);

    }catch(Exception e){
        //
   
}
    return id;
}

//获取
public static String getString(RecordStore rs,int id){
        try {
            byte[] b = rs.getRecord(id);
            return (new String(b));
        } catch (RecordStoreNotOpenException ex) {
            ex.printStackTrace();
        } catch (InvalidRecordIDException ex) {
            ex.printStackTrace();
        } catch (RecordStoreException ex) {
            ex.printStackTrace();
        }
        return null;

}
//修改
public static void setString(RecordStore rs,int id,String newString){
    byte[] b=newString.getBytes();
        try {
            rs.setRecord(id, b, 0, b.length);
        } catch (Exception ex) {

        }
}
//添加证书数据记录
public static int writeInt(RecordStore rs,int myInt){
    int id=-1;
    String myString=(new Integer(myInt)).toString();
    id=writeString(rs,myString);
    return id;
}
//获取
public static int getInt(RecordStore rs,int id){
    int result=Integer.MAX_VALUE;
    String s=getString(rs,id);
    try{
    result=Integer.parseInt(s);
    }catch(Exception e){

    }
    return result;
}
//修改
public static void setInt(RecordStore rs,int newInt){
    String myString=(new Integer(newInt)).toString();
}

}

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class GraphicsTest extends MIDlet{
  private Display display;

    public GraphicsTest() {
        display=Display.getDisplay(this);

    }

    protected void destroyApp(boolean unconditional)  {

    }

    protected void pauseApp() {

    }

    protected void startApp(){
     MyCanvas mc=new MyCanvas();
     display.setCurrent(mc);
    }

}
class MyCanvas extends Canvas {

    public void paint(Graphics g){
     int width=getWidth();
     int height=getHeight();
String a[]={"静夜思","李白","床前明月光","疑是地上霜","举头望明月","低头思故乡"};
     g.setColor(0);
     g.fillRect(0, 0, width, height);

   
     g.setColor(0Xffff00);
     Font font=g.getFont();
     font=Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_UNDERLINED,Font.SIZE_LARGE);
     g.setFont(font);
     for(int i=0;i<a.length;i++){
         g.drawString(a[i], 0, i*20,Graphics.LEFT|Graphics.BASELINE );
     }
   
    }

}

 //--------------------------------------------------------------------------------------------
利用移动原点坐标动起来之后的静夜思

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class GraphicsTest extends MIDlet{
  private Display display;

    public GraphicsTest() {
        display=Display.getDisplay(this);

    }

    protected void destroyApp(boolean unconditional)  {

    }

    protected void pauseApp() {

    }

    protected void startApp(){
     MyCanvas mc=new MyCanvas();
     display.setCurrent(mc);
    }

}
class MyCanvas extends Canvas {
int aa=300;

MyCanvas(){
Walk w = new Walk();
  w.start();
}
    public void paint(Graphics g){
     int width=getWidth();
     int height=getHeight();
String a[]={"静夜思","李白","床前明月光","疑是地上霜","举头望明月","低头思故乡"};
     g.setColor(0);
     g.fillRect(0, 0, width, height);

     g.setColor(0Xffff00);
     g.translate(80,aa);
     Font font=g.getFont();

     font=Font.getFont(Font.FACE_PROPORTIONAL,Font.FACE_SYSTEM,Font.SIZE_LARGE);
     g.setFont(font);
     for(int i=0;i<a.length;i++){
         g.drawString(a[i], 0, i*20,20);
     }

    }

class Walk extends Thread{

  public void run(){
   while(aa>80){
    aa--;
    repaint();
    try{
     sleep(50);
    }catch(Exception ee){}
   }
  }
 }

}

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class GraphicsTest extends MIDlet{
  private Display display;

    public GraphicsTest() {
        display=Display.getDisplay(this);

    }
 
    protected void destroyApp(boolean unconditional)  {
     
       
    }

    protected void pauseApp() {
       
    }

    protected void startApp(){
     MyCanvas mc=new MyCanvas();
     display.setCurrent(mc);
    }

}
class MyCanvas extends Canvas {

    public void paint(Graphics g){
     int width=getWidth();
     int height=getHeight();
    
     g.setColor(0);
     g.fillRect(0, 0, width, height);
    
     int a=width/5;
     int b=height/5;
     g.setColor(0Xffff00);
     for(int i=1;i<=4;i++){
     g.drawLine(a,0 ,a,height);
     g.drawLine( 0,b,  width,b);
     a=a+width/5;
     b=b+height/5;
    
     } g.drawArc(0, 0, width, height, 0, 360);
    }

}

public class SimpleCanvas extends MIDlet{
  private Display display;

    public SimpleCanvas() {
        display=Display.getDisplay(this);

    }
 
    protected void destroyApp(boolean unconditional)  {
     
       
    }

    protected void pauseApp() {
       
    }

    protected void startApp(){
     MyCanvas mc=new MyCanvas();
     display.setCurrent(mc);
    }

}
class MyCanvas extends Canvas {

    public void paint(Graphics g){
      g.setColor(0,0,0);
      g.fillRect(0,0,getWidth(),getHeight());
      g.setColor(255, 255,255);
      g.drawString("你好,测试", 100, 100, 0);
    }

}