Version: 9.4.5.v20170502
Version: 9.4.5.v20170502 |
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The RewriteHandler matches a request against a set of rules, and modifies the request accordingly for any rules that match.
The most common use is to rewrite request URIs, but it is capable of much more: rules can also be configured to redirect the response, set a cookie or response code on the response, modify the header, etc.
The standard Jetty distribution bundle contains the jetty-rewrite module, so all you need to do is to enable it using one of the module commands, eg:
$ java -jar start.jar --add-to-start=rewrite
Note
If you are running the standard Jetty distribution with the sample test webapp, there will be a demo of the rewrite module at http://localhost:8080/test/rewrite/
The rewrite module enables the following Jetty xml config file on the execution path:
<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">
<Configure id="Server" class="org.eclipse.jetty.server.Server">
<!-- =========================================================== -->
<!-- configure rewrite handler -->
<!-- =========================================================== -->
<Call name="insertHandler">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RewriteHandler">
<Set name="rewriteRequestURI"><Property name="jetty.rewrite.rewriteRequestURI" deprecated="rewrite.rewriteRequestURI" default="true"/></Set>
<Set name="rewritePathInfo"><Property name="jetty.rewrite.rewritePathInfo" deprecated="rewrite.rewritePathInfo" default="false"/></Set>
<Set name="originalPathAttribute"><Property name="jetty.rewrite.originalPathAttribute" deprecated="rewrite.originalPathAttribute" default="requestedPath"/></Set>
<!-- Set DispatcherTypes -->
<Set name="dispatcherTypes">
<Array type="javax.servlet.DispatcherType">
<Item><Call class="javax.servlet.DispatcherType" name="valueOf"><Arg>REQUEST</Arg></Call></Item>
<Item><Call class="javax.servlet.DispatcherType" name="valueOf"><Arg>ASYNC</Arg></Call></Item>
</Array>
</Set>
<Get id="Rewrite" name="ruleContainer"/>
<!-- see rewrite-compactpath.xml for example how to add a rule -->
</New>
</Arg>
</Call>
</Configure>As the commented out code shows, you configure the RewriteHandler by adding various rules.
There is an example of rules configuration in the standard distribution in the demo-base/etc/demo-rewrite-rules.xml file:
<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">
<!-- =============================================================== -->
<!-- Configure the demos -->
<!-- =============================================================== -->
<Configure id="Server" class="org.eclipse.jetty.server.Server">
<!-- ============================================================= -->
<!-- Add rewrite rules -->
<!-- ============================================================= -->
<Ref refid="Rewrite">
<!-- Add rule to protect against IE ssl bug -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.MsieSslRule"/>
</Arg>
</Call>
<!-- protect favicon handling -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.HeaderPatternRule">
<Set name="pattern">/favicon.ico</Set>
<Set name="name">Cache-Control</Set>
<Set name="value">Max-Age=3600,public</Set>
<Set name="terminating">true</Set>
</New>
</Arg>
</Call>
<!-- redirect from the welcome page to a specific page -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RewritePatternRule">
<Set name="pattern">/test/rewrite/</Set>
<Set name="replacement">/test/rewrite/info.html</Set>
</New>
</Arg>
</Call>
<!-- replace the entire request URI -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RewritePatternRule">
<Set name="pattern">/test/some/old/context</Set>
<Set name="replacement">/test/rewritten/newcontext</Set>
</New>
</Arg>
</Call>
<!-- replace the beginning of the request URI -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RewritePatternRule">
<Set name="pattern">/test/rewrite/for/*</Set>
<Set name="replacement">/test/rewritten/</Set>
</New>
</Arg>
</Call>
<!-- reverse the order of the path sections -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RewriteRegexRule">
<Set name="regex">(.*?)/reverse/([^/]*)/(.*)</Set>
<Set name="replacement">$1/reverse/$3/$2</Set>
</New>
</Arg>
</Call>
<!-- add a cookie to each path visited -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.CookiePatternRule">
<Set name="pattern">/*</Set>
<Set name="name">visited</Set>
<Set name="value">yes</Set>
</New>
</Arg>
</Call>
<!-- actual redirect, instead of internal rewrite -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.RedirectPatternRule">
<Set name="pattern">/test/redirect/*</Set>
<Set name="location">/test/redirected</Set>
</New>
</Arg>
</Call>
<!-- add a response rule -->
<Call name="addRule">
<Arg>
<New class="org.eclipse.jetty.rewrite.handler.ResponsePatternRule">
<Set name="pattern">/400Error</Set>
<Set name="code">400</Set>
<Set name="reason">ResponsePatternRule Demo</Set>
</New>
</Arg>
</Call>
</Ref>
</Configure>This is an example for embedded Jetty, which does something similar to the configuration file example above:
Server server = new Server();
RewriteHandler rewrite = new RewriteHandler();
rewrite.setRewriteRequestURI(true);
rewrite.setRewritePathInfo(false);
rewrite.originalPathAttribute("requestedPath");
RedirectPatternRule redirect = new RedirectPatternRule();
redirect.setPattern("/redirect/*");
redirect.setReplacement("/redirected");
rewrite.addRule(redirect);
RewritePatternRule oldToNew = new RewritePatternRule();
oldToNew.setPattern("/some/old/context");
oldToNew.setReplacement("/some/new/context");
rewrite.addRule(oldToNew);
RewriteRegexRule reverse = new RewriteRegexRule();
reverse.setRegex("/reverse/([^/]*)/(.*)");
reverse.setReplacement("/reverse/$2/$1");
rewrite.addRule(reverse);
server.setHandler(rewrite);There are several types of rules that are written extending useful base rule classes.
Matches against the request URI using the servlet pattern syntax.
Matches against the request URI using regular expressions.
Template:$n to replace the nth capture group.)Match against request headers. Match either on a header name and specific value, or on the presence of a header (with any value).
Extra rules that defy standard classification.
Groups rules together.
The contained rules will only be processed if the conditions for the RuleContainer evaluate to true.