classsave.java

自己随便写的一个J2ME的小程序。ECLIPSE打开就好了。

import javax.microedition.rms.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

//在使用这个数据库的之前的话,前调用他的OPEN()函数来打开他
public class ClassSave  {
	

	public 	RecordStore rs;
	private String rsName;
	
public ClassSave(String recordName)
{
	
rsName=recordName;

this.open();

}

public boolean open()
{
	try
	{
		
	rs=RecordStore.openRecordStore(rsName, true);

	if(rs!=null)return true;
	}
	catch(Exception e)
	{
		
	System.out.println("数据的打开有错      "+e);
	}
 return false;

}

public void close()
{
	

try
{
rs.closeRecordStore();	
}

catch(Exception e)
{
System.out.println("数据的关闭有错    "+e);	

}




}


public boolean empty()//
{
	
try
{
if(rs.getNumRecords()>0)
{
return false;	

}
else
{
return true;	

}


}
catch(Exception e)
{
System.out.println("查询数据是否为空的时候出错   "+e);	

}


return true;
}

public void setRecord(String pass,int i)//修改你的数据存储,pass是你的字符串,i是你的要修改的ID
{
	

	   ByteArrayOutputStream baos=new ByteArrayOutputStream();
	   
	   DataOutputStream outputStream=new DataOutputStream(baos);
	  
	  int id=-1;
	  try
	  {
		  
		  outputStream.writeUTF(pass);
		 // byte[] Temp=new byte[];
		  //outputStream.writeInt(coord);
		  
		  
	  }
	  catch(IOException ioe)
	  {
		  System.out.println(ioe);
		  
		  
	  }
	byte[] b=baos.toByteArray();

	
	
try
{
if(empty())
{
rs.addRecord(b, 0, b.length);


}
else 
{
rs.setRecord(i, b, 0, b.length);

}


}
catch(Exception e)
{
System.out.println("添加数据的时候出错   "+e);	

}


}


public String getRecord(int i)//得到需要的数据记录,i是储存的记录
{
	
i=1;	
byte buffer[];
String Temp;
ByteArrayInputStream bais;
DataInputStream inputStream;
try
{
buffer=rs.getRecord(i);
bais=new ByteArrayInputStream(buffer);

inputStream=new DataInputStream(bais);

Temp=inputStream.readUTF();



inputStream.close();
bais.close();


return Temp;


}
catch(Exception e)
{
	
System.out.println("获取数据的时候出错   "+e);

}

return null;


}


public void deleteRecord()
{
	

try
{
rs.deleteRecordStore(rsName);	

}
catch(Exception e)
{
	
System.out.println("删除数据的时候出错   "+e);

}
}

public int addRecord(String buffer)
{
   ByteArrayOutputStream baos=new ByteArrayOutputStream();
   
   DataOutputStream outputStream=new DataOutputStream(baos);
  
  int id=-1;
  try
  {
	  
	  outputStream.writeUTF(buffer);
	 // byte[] Temp=new byte[];
	  //outputStream.writeInt(coord);
	  
	  
  }
  catch(IOException ioe)
  {
	  System.out.println(ioe);
	  
	  
  }
byte[] b=baos.toByteArray();

try
{
id=rs.addRecord(b, 0, b.length);	

}
catch(RecordStoreException rse)
{
System.out.println(rse);	

}
try
{
	outputStream.close();
	baos.close();
	
}

catch(IOException ios)
{
System.out.println(ios);	

}

return id;
}

	
	

}