java面包屑导航制作

做了个简单的面包屑导航功能,比如页面上大家经常看到的这种导航:

 

您所在的位置:音乐社区-->用户模块-->用户注册

 

我做成了标签的形式,利用jom4j来解析xml文件:

核心类SiteMapTag:

package org.forever.tag;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

/**
 * 站点导航标签的实现
 * @author Administrator
 *
 */
public class SiteMapTag extends TagSupport {

	private static final long serialVersionUID = -3531938467909884528L;
	private String currentFilePath;
	private Element target;
	
	@Override
	public int doStartTag() throws JspException {
		HttpServletRequest request = (HttpServletRequest) this.pageContext.getRequest();
		currentFilePath = request.getRequestURI().replaceFirst(request.getContextPath(), "");
		try {
			Element root = (Element)pageContext.getServletContext().getAttribute("webSiteMapSet");
			if(root==null){
				SAXReader reader = new SAXReader();
				InputStream inputStream = SiteMapTag.class.getClassLoader().getResourceAsStream("sitemap.xml");
				Document document = reader.read(inputStream);
				root = document.getRootElement();
				pageContext.getServletContext().setAttribute("webSiteMapSet", root);
			}
			parseParent(root);
			StringBuffer content = new StringBuffer("");
			List titles = new ArrayList();
			List hrefs = new ArrayList();
			
			while(target!=null){
				Attribute attTitle = target.attribute("title");
				if(attTitle!=null){
					titles.add(attTitle.getText());
				}
				
				Attribute attHref = target.attribute("href");
				if(attHref!=null){
					hrefs.add(attHref.getText());
				}else{
					hrefs.add("");
				}
				
				target = target.getParent();
			}
			
			for (int i = titles.size()-1; i >=0; i--) {
				String href = hrefs.get(i);
				if(href.equals("")){
					content.append(titles.get(i)+"-->");
				}else{
					content.append(""+titles.get(i)+"-->");
				}
				
			}
			if(content.length()>0){
				this.pageContext.getOut().println(content.delete(content.length()-6, content.length()));
			}
			

		} catch (Exception e) {
			e.printStackTrace();
			throw new JspException(e);
		}
		
		
		return super.doStartTag();
	}

	private void parseParent(Element parent){
		Iterator it = parent.elementIterator();
		while(it.hasNext()){
			Element temp = it.next();
			Attribute attr = temp.attribute("path");
			if(attr!=null){
				if(attr.getText().equals(currentFilePath)){
					target = temp;
					return;
				}
			}
			parseParent(temp);
		}
	}
	
}

 sitemap.tld文件:




    
    站点导航标签
	myTaglib siteMap
	1.1    
    tagUtil
    http://tag.forever.org/jsp/tagutil/sitemap

    
		面包屑标签
		siteMap
		org.forever.tag.SiteMapTag
		empty
    
    

 在项目的src下面添加sitemap.xml文件:





	
		
	

 

要使用的jsp加入标签指令:

<%@taglib uri="http://tag.forever.org/jsp/tagutil/sitemap" prefix="tagUtil" %>

 在想放的位置处加上标签:

您所在的位置:就可以了。

sitemap.jar带源码。用的时候别忘了添加jom4j的支持。

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