goodsfield.java

一个简单的商品采集系统

import javax.swing.*;

//the definition of the field
public class GoodsField extends ItemAttribute {
	//value of the attribute 
	private String value;
	//data type
    public final int INTEGER = 1, FLOATING = 2, STRING = 3;
    //constrain tag
    public final boolean CONSTRAIN_TRUE = true, CONSTRAIN_FALSE = false;
    //constrain type that is every integer maping a type of constrain content
    public final int KEY = 1, ELSE = 2;
    
	public GoodsField ()
	{
		//default
		super ( "", 0, 0, true, 0 );
		setValue ( null );
	}
	
	public GoodsField ( String gn, int gt, int gl, boolean gct, int gc, String gv )
	{
		super ( gn, gt, gl, gct, gc );
		setValue ( gv );
	}
	
	//use this Constructor most
	public GoodsField ( ItemAttribute ga, String gv )
	{
		super ( ga.getName(), ga.getType(), ga.getLength(), ga.getConstrainTag(), ga.getConstrain() );
		setValue( gv );
	}
	
	public void setValue ( String gv )
	{
		//the constrains.Here need to improve
		if( getConstrainTag() == CONSTRAIN_TRUE )
		{
			switch( getType() )
			{
				case INTEGER: 
				             int v1 = Integer.parseInt( gv );
				             if( !( v1 < 0 ) )
				               value = gv;
				               else{
				               	value = null;
				               	JOptionPane.showMessageDialog( null,
				               	"Valid data type of "+getName(),
				               	null, JOptionPane.ERROR_MESSAGE );
				               }
				             break;
				             
				case FLOATING:
				             double v2 = Double.parseDouble( gv );
				             if( !( v2 < 0 ))
				               value = gv;
				               else{
				               	value = null;
				               	JOptionPane.showMessageDialog( null,
				               	"Valid data type of "+getName(),
				               	null, JOptionPane.ERROR_MESSAGE );
				               }
				             break;
				              
				case STRING:
				             if( getLength() >= gv.length() & gv.length() != 0 )
				               value = gv;
				               else{
				               	value = null;
				               	JOptionPane.showMessageDialog( null,
				               	"Valid data length of "+getName(),
				               	null, JOptionPane.ERROR_MESSAGE );
				               }
				             break;
				default:
				             JOptionPane.showMessageDialog( null,
				               	"No such data type",null, JOptionPane.ERROR_MESSAGE );
				             break;	
			}
		}
		else
		  value = gv;
	}
	
	public String getValue ()
	{
		return value;
	}
	
   public String toString()
	{
		String buf = new String("");
        buf += getName()+"\t"+getType()+"\t"+getLength()+"\t"+getConstrainTag()+"\t"+getConstrain();
        buf += "\t" + getValue();
        return buf; 
	}
}