myiteratetag.java

一个javaweb开的小例子

package cn.com.pkusoft.tag;

import java.util.Collection;
import java.util.Iterator;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.BodyTagSupport;
import javax.servlet.jsp.tagext.Tag;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: pku-soft</p>
 * @author weiming
 * @version 1.0
 */

public class MyIterateTag
    extends BodyTagSupport
{

    private String type = null;
    private String name = null;
    private Collection collection = null;
    private Iterator m_iterator = null;

    public MyIterateTag()
    {
    }

    public void setCollection(Collection collection)
    {
        this.collection = collection;
    }

    public void setType(String type)
    {
        this.type = type;
    }

    public void setPageContext(PageContext pc)
    {
        /**@todo Implement this javax.servlet.jsp.tagext.Tag abstract method*/
        this.pageContext = pc;
    }

    public void doInitBody() throws JspException
    {

    }

    public void setParent(Tag parm1)
    {
        /**@todo Implement this javax.servlet.jsp.tagext.Tag abstract method*/
    }

    public Tag getParent()
    {
        /**@todo Implement this javax.servlet.jsp.tagext.Tag abstract method*/
        throw new java.lang.UnsupportedOperationException(
            "Method getParent() not yet implemented.");
    }

    public int doStartTag() throws JspException
    {
        this.collection = (Collection) pageContext.getSession().getAttribute(this.
            name);

        if (collection == null)
        {
            return SKIP_BODY;
        }

        m_iterator = this.collection.iterator();
        if (this.m_iterator.hasNext()) {
            this.pageContext.getSession().setAttribute(this.getId(), this.m_iterator.next());
            return EVAL_BODY_INCLUDE;
        }
        else {
            return SKIP_BODY;
        }

    }

    public int doAfterBody() throws JspException
    {

        if (this.m_iterator.hasNext()) {
            this.pageContext.getSession().setAttribute(this.getId(), this.m_iterator.next());
            return EVAL_BODY_AGAIN;
        }
        else {
            return SKIP_BODY;
        }

    }

    public int doEndTag() throws JspException
    {
        return super.doEndTag();
    }

    public void setName(String name)
    {
        this.name = name;
    }

}