getfieldtag.java

JSP学习的好东东

import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
import java.sql.*;
import java.util.*;

public class GetFieldTag extends TagSupport
{
	private String name;
	public void setName(String name)
	{
		this.name = name;
		System.out.println("GetFieldTag.setName()......");
	}
	public int doStartTag() throws JspException
	{
		System.out.println("GetFieldTag.doStartTag()......");
		return EVAL_PAGE;
	}
	public int doEndTag() throws JspException
	{
		ConnectTag ct = (ConnectTag)findAncestorWithClass(this,ConnectTag.class);
		if( ct == null){
			throw new JspException("In [GetFieldTag]:No ConnectTag Object error.");
		}
		ResultSet rs = ct.getResultSet();
		if(rs == null ){
			throw new JspException("No resultset.");
		}
		try{
			JspWriter out = pageContext.getOut();
			String tmpField = rs.getString(name);
			out.write(tmpField);
		}catch(SQLException e){
			throw new JspException(e.getMessage());
		}catch(IOException e){
			throw new JspException(e.getMessage());
		}
		
		System.out.println("GetFieldTag.doEndTag()......");
		return EVAL_PAGE;
	
				
	}
	
	
}