outtag.java

张新曼 精通JSP Web 开发技术与典型应用 随书光盘源码

package ch10;

import java.io.IOException;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.TagSupport;

public class OutTag extends TagSupport
{
	/**
	 * 添加缺省串行版本标识
	 */
	private static final long serialVersionUID = 1L;
	private Object value;	
	
    /**
     *覆盖doStartTag方法
     */
   public void setValue(Object value)
   {
   	 this.value=value;
   }
   
    public int doStartTag() throws JspTagException {
	return EVAL_BODY_INCLUDE;
    }
    
    /**
     *覆盖doEndTag方法
     */
	public int doEndTag()throws JspTagException
	{

		try
		{
			System.out.println(value);
			pageContext.getOut().write(value.toString());
			
		}
		catch(IOException ex)
		{
			throw new JspTagException("Fatal error:hello tag conld not write to JSP out");
		}
		return EVAL_PAGE;
	}
      
}