retest.java

J2ME开发实例,内含有可直接运行的源程序代码,供大家学习参考

//RETest.java
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.*;
import javax.microedition.rms.* ;
public class RETest extends MIDlet
{
	private Display display;
	public RETest()
	{
		display = Display.getDisplay(this);
	}
	public void startApp()
	{
		String dbname = "testdb" ;
		Form f = new Form("RE Test") ;
		RecordStore rs = openRSAnyway(dbname) ;
		if( rs == null )
		{
			f.append("Table open fail") ;
		}
		else
		{
			try
			{
				byte []data = new byte[2] ;
				data[0] = 15 ;
				data[1] = 16 ;
				rs.addRecord(data,0,data.length) ;
				data[0] = 25 ;
				data[1] = 26 ;
				rs.addRecord(data,0,data.length) ;
				data[0] = 35 ;
				data[1] = 36 ;
				rs.addRecord(data,0,data.length) ;
				travelRS(rs) ;
				rs.closeRecordStore() ;
				deleteRS(dbname) ;
			}
			catch(Exception e){}
			display.setCurrent(f) ;
		}
	}
	public void pauseApp(){}
	public void destroyApp(boolean unconditional){}
	public void travelRS(RecordStore rs)
	{
		try
		{
			RecordEnumeration re =
				rs.enumerateRecords(null,null,false) ;
			System.out.println("There are " + re.numRecords() +
					   " in RecordStore") ;
			while(re.hasNextElement())
			{
				byte tmp[] = re.nextRecord() ;
					System.out.println(tmp[0] + " " + tmp[1]) ;
			}
		}
		catch(Exception e)
		{ }
	}
	public RecordStore openRSAnyway(String rsname)
	{
		RecordStore rs = null ;
		if(rsname.length() > 32)
			return null ;
		try
		{
			rs = RecordStore.openRecordStore(rsname,true) ;
			return rs ;
		}
		catch(Exception e)
		{
			return null ;
		}
	}
	public boolean deleteRS(String rsname)
	{
		if(rsname.length() > 32)
			return false ;
		try
		{
			RecordStore.deleteRecordStore(rsname) ;
		}
		catch(Exception e)
		{
			return false ;
		}
		return true ;
	}
}