Java URLRewrite重定向

urlrewrite的主要作用：

    1）隐藏真实URL，提高安全性

    2）更加友好的URL，好记（看博客园就行知道啦）

    3）便于搜素引擎收录

首先，准备工作，下载urlrewrite：http://code.google.com/p/urlrewritefilter/downloads/list

可以随意选择自己喜好的版本下载。copy jar包到lib目录中，然后copy urlrewriter.xml到WEB-INF目录下，提供urlrewriter.xml文件内容：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE urlrewrite PUBLIC "-//tuckey.org//DTD UrlRewrite 2.6//EN"
"http://tuckey.org/res/dtds/urlrewrite2.6.dtd">

<!--

Configuration file for UrlRewriteFilter http://tuckey.org/urlrewrite/ 
-->
<urlrewrite>

<rule>
<note>
The rule means that requests to /test/status/ will be redirected to /rewrite-status
the url will be rewritten.
</note>
<from>/test/status/</from>
<to type="redirect">%{context-path}/rewrite-status</to>
</rule>

<outbound-rule>
<note>
The outbound-rule specifies that when response.encodeURL is called (if you are using JSTL c:url)
the url /rewrite-status will be rewritten to /test/status/.

The above rule and this outbound-rule means that end users should never see the
url /rewrite-status only /test/status/ both in thier location bar and in hyperlinks
in your pages.
</note>
<from>/rewrite-status</from>
<to>/test/status/</to>
</outbound-rule>

<!--

INSTALLATION

in your web.xml add...

<filter>
<filter-name>UrlRewriteFilter</filter-name>
<filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
<init-param>
<param-name>logLevel</param-name>
<param-value>WARN</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>UrlRewriteFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

EXAMPLES

Redirect one url
<rule>
<from>/some/old/page.html</from>
<to type="redirect">/very/new/page.html</to>
</rule>

Redirect a directory
<rule>
<from>/some/olddir/(.*)</from>
<to type="redirect">/very/newdir/$1</to>
</rule>

Clean a url
<rule>
<from>/products/([0-9]+)</from>
<to>/products/index.jsp?product_id=$1</to>
</rule>
eg, /products/1234 will be passed on to /products/index.jsp?product_id=1234 without the user noticing.

Browser detection
<rule>
<condition name="user-agent">Mozilla/[1-4]</condition>
<from>/some/page.html</from>
<to>/some/page-for-old-browsers.html</to>
</rule>
eg, will pass the request for /some/page.html on to /some/page-for-old-browsers.html only for older
browsers whose user agent srtings match Mozilla/1, Mozilla/2, Mozilla/3 or Mozilla/4.

-->

</urlrewrite>

添加 filter到web.xml：

<filter>
<filter-name>UrlRewriteFilter</filter-name>
<filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
<init-param>
<param-name>logLevel</param-name><!--这里设置log日志级别 -->
<param-value>WARN</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>UrlRewriteFilter</filter-name>
<url-pattern>/*</url-pattern> <!--拦截所有URL请求 --></span>
</filter-mapping>

PS：如果使用的是struts2框架， urlrewrite的filter需要在struts2的filter之前

urlrewrite中含有两个标签<rule>和<outbound-rule>，

<rule>
<note>
The rule means that requests to /test/status/ will be redirected to /rewrite-status
the url will be rewritten.
</note>
<from>/test/status/</from>
<to type="redirect">%{context-path}/rewrite-status</to>
</rule>

<rule>会把你的请求链接根据你写好的规则转换成对应的请求，也就是<rule>的子标签和<from>和<to>，<from>代表来源链接(伪链接)，<to>代表转换后的连接(真实链接)。比如上面的请求，会把/test/status/转换成/rewrite-status请求服务器中内容。

<outbound-rule>
<note>
The outbound-rule specifies that when response.encodeURL is called (if you are using JSTL c:url)
the url /rewrite-status will be rewritten to /test/status/.

The above rule and this outbound-rule means that end users should never see the
url /rewrite-status only /test/status/ both in thier location bar and in hyperlinks
in your pages.
</note>
<from>/rewrite-status</from>
<to>/test/status/</to>
</outbound-rule>

<outbound-rule>就是把你页面上的URL根据规则转换对应的的美化后的URL，<outbound-rule> 需要重写URL，可以使用response.encodeURL  或者 JSTL<c:url>标签，<from>标签中的是真实链接，<to>中的是伪链接。这个标签会把你包含/rewrite-status的链接转换成/test/status/。

<from>和<to>中标签都是根据正则来进行匹配

<rule>
<from>^/company/([0-9]+).html$</from>
<to>/goods/company.jsp?companyId=$1</to>
</rule>

参数需要用()包围起来。[0-9]+代表一个或多个0-9的数字。

<from>标签中有两个小字符"^"和"$"。

“^”这个小字符，根据我的测试，代表你的项目URL，比如我的是http://localhost:8080/urlrewriteDemo/，如果你的请求是http://localhost:8080/urlrewriteDemo/company/1.html，则会被转换成http://localhost:8080/urlrewriteDemo/goods/company.jsp?companyId=1。

如果你的请求http://localhost:8080/urlrewriteDemo/test/company/1.html则不会被转换，因为匹配不上，如果去掉"^"，则可以匹配上，请求会被转换成http://localhost:8080/urlrewriteDemo/test/goods/company.jsp?companyId=1。

"$"代表任意字符串，也就是说，你的请求字符串http://localhost:8080/urlrewriteDemo/company/1.html，无论在后面加什么字符串，比如说http://localhost:8080/urlrewriteDemo/company/1.html?id=1111，也只会转换成http://localhost:8080/urlrewriteDemo/goods/company.jsp?companyId=1，如果没有"$"，则会被转换成http://localhost:8080/urlrewriteDemo/goods/company.jsp?companyId=1?id=1111