通过Filter实现二级域名和URLRewrite

通过Filter实现二级域名和URLRewrite 文章分类:Java编程 需求1.1： 一级域名： http://www.iteye.com/ 二级域名： http://firefly.iteye.com/ 这里firefly其实会Mapping到用户ID，根据用户ID来展示不用用户的Blog，javaeye是通过Ruby实现的， 那Java如何实现这个Mapping呢？ 需求1.2： 我们查看具体的哪一篇文章是通过 http://firefly.iteye.com/blog/785171 来访问的，这个URL是如何传参数的呢？ 思路2： A. 通过过滤器获得二级域名.（eg. firefly） B. 对URL进行重写Rewrite. 实现3： 3.1 创建一个URLFilter过滤器,对所有的请求进行过滤 package com.firefly.web; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import com.firefly.web.URLRewriter.URLMapping; import com.thoughtworks.xstream.XStream; import com.thoughtworks.xstream.io.xml.DomDriver; /** * Servlet Filter implementation class URLFilter */ public class URLFilter implements Filter { List <urlmapping>urlPatternList; public URLFilter() { // TODO Auto-generated constructor stub } /** * @see Filter#init(FilterConfig) */ public void init(FilterConfig fConfig) throws ServletException { /** * 初始化 */ String configPath=fConfig.getInitParameter("configPath"); String realConfigPath=fConfig.getServletContext().getRealPath(configPath); FileInputStream input; byte buff[]=null; try { input = new FileInputStream(realConfigPath); buff=new byte[input.available()]; input.read(buff); input.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } /** * 通过开源XStream来解析XML，并转化成Java对象 */ XStream xstream = new XStream(new DomDriver()); xstream.alias("url", URLMapping.class); xstream.alias("URLList", ArrayList.class); urlPatternList=(List)xstream.fromXML(new String(buff)); } /** * @see Filter#destroy() */ public void destroy() { // TODO Auto-generated method stub } /** * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain) */ public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest httpServletRequest = (HttpServletRequest) request; /** * 获得服务器名称，如：firefly.iteye.com/ */ String serverName=request.getServerName(); int endIndex=serverName.indexOf("."); /** * 获得二级域名 * 二级域名一般是一个ID, 如：firefly */ String secondDomainName=serverName.substring(0, endIndex); request.setAttribute("userID", secondDomainName); if(secondDomainName.equalsIgnoreCase("www")){ httpServletRequest.getRequestDispatcher( "/index.html") .forward(request, response); return; }else{ String realPath=this.getRealPath(httpServletRequest.getRequestURI()); httpServletRequest.getRequestDispatcher("/"+realPath) .forward(request, response); return; } } /** * 将URI转换成真正的请求URL * e.g firefly.iteye.com/blog/785171 -&gt; * firefly.iteye.com/dispatcher.do?action=displayBlog&amp;blogId=785171 * @param URI * @return */ private String getRealPath(String URI){ for(URLMapping url:urlPatternList){ Pattern pattern=Pattern.compile(url.getPattern()); Matcher matcher=pattern.matcher(URI); if(matcher.find()){ String reqPara=url.getReqParameter(); for(int i=1;i <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"><display-name>parseDomain</display-name><filter><description></description><display-name>URLFilter</display-name><filter-name>URLFilter</filter-name><filter-class>com.firefly.web.URLFilter</filter-class><init-param><param-name>configPath</param-name><param-value>/WEB-INF/URLRewriter.xml</param-value></init-param></filter><filter-mapping><filter-name>URLFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping><welcome-file-list><welcome-file>index.html</welcome-file></welcome-file-list></web-app> 3.4 在/WEB-INF下创建URLRewriter.xml <?xml version="1.0" encoding="utf-8" ?><urllist><url><pattern>/order/(\d*)/(\d*)</pattern><reqparameter>dispatcher.do?action=order&amp;productId=${1}&amp;number=${2}</reqparameter></url><url><pattern>/blog/(\d*)</pattern><reqparameter>dispatcher.do?action=displayBlog&amp;blogId=${1}</reqparameter></url></urllist> 附言： 如果要在本地测试二级域名，需要在hosts文件中配置如下参数(C:\WINDOWS\system32\drivers\etc\hosts) 127.0.0.1 firefly.iteye.com http://firefly.iteye.com/blog/821715</urlmapping>