{"id":123,"date":"2009-04-10T23:09:53","date_gmt":"2009-04-10T22:09:53","guid":{"rendered":"http:\/\/lqd.hybird.org\/journal\/?p=123"},"modified":"2013-06-24T18:01:59","modified_gmt":"2013-06-24T17:01:59","slug":"hacking-jerseyjax-rs-to-run-restful-web-services-on-google-appenginejava","status":"publish","type":"post","link":"https:\/\/lqd.hybird.org\/journal\/?p=123","title":{"rendered":"Hacking Jersey\/JAX-RS to run RESTful web services on Google AppEngine\/Java"},"content":{"rendered":"

Update: this article is about Jersey 1.0.2, i’ll update the modifications i made for the 1.1.0-ea version soon.<\/p>\n

Jersey doesn’t run out of the box on GAE, and since i can’t wait for a new release to try RESTful services on AppEngine\/Java, let’s modify its servlet container so it will at least run basic samples.<\/p>\n

I really find Jersey\/JAX-RS compelling, while others think it could be the ultimate framework<\/a>, and with all the recent buzz about the AppEngine platform, i wanted to try and make the two meet, grab a little dinner, a glass of wine or two, and make sweet web service babies. That didn’t go as easily as I planned, but after a little hacking i was able to run basic examples, which is probably enough for now, until a later release fixes the issues.<\/p>\n

In this post i’ll describe what i did to make Jersey’s basic servlet example work (ie. what i broke) and provide you with the code (code + binary here<\/a>) so you can try it on your own.<\/p>\n

AppEngine runs a tight ship with strict security policies, which caused most of the errors you get using Jersey: classes you can’t access inside their sandbox. I’ve done my best bypassing those errors, and in doing so i actually removed and broke features, some of which i know about, the others, well, i don’t (:<\/p>\n

The people following my twitter stream<\/a> know i learned the hard way that the dev server google provides with its eclipse plugin doesn’t enforce the same security policies as their appspot servers (why is that is a question to which i don’t have the answer), and the kicker is that Jersey runs fine in their dev server….<\/p>\n

The first major error you encounter is related to javax.naming.InitialContext, the second one to JAXB binding for WADL generation. I removed both the WADL pregeneration and root resources registration in the JNDI context. I don’t care much for WADL so it’s not a big loss anyway, however i’m not totally sure how the JNDI context is used inside Jersey. This might break something more useful.<\/p>\n

A couple more classloader errors, and other tiny issues, and we’re good to go.<\/p>\n

Here’s how to make the Jersey basic servlet sample (simple-servlet) run on AppEngine (which you’ll be able to see here for a little while, if you want to test it. It comes with a little ajax ui changing Accept headers, choosing resources to test, etc)<\/p>\n

Create a GAE using the Google plugin for Eclipse, add the jersey jars into the war\/WEB-INF\/lib directory (i used the jersey archive found here<\/a> to get Jersey, its dependencies and the samples), while you’re at it also add the modified jersey servlet container there, jersey-appengine-container_0.1.jar found in the linked zip file.<\/p>\n

Add the modified servlet (org.hybird.appengine.jersey.container.ServletContainer) to web.xml:<\/p>\n

[sourcecode language=’xml’]
\n
\nJersey Web Application<\/servlet-name>
\norg.hybird.appengine.jersey.container.ServletContainer<\/servlet-class>
\n\ncom.sun.jersey.config.property.packages<\/param-name>\ncom.sun.jersey.samples.servlet.resources<\/param-value>\n<\/init-param>
\n1<\/load-on-startup>
\n<\/servlet>
\n
\nJersey Web Application<\/servlet-name>
\n\/resources\/*<\/url-pattern>
\n<\/servlet-mapping>
\n[\/sourcecode]<\/p>\n

Now you can take the simple-servlet sample, copy its index.html in the war folder, and java source files inside your src. And if i remember correctly, that should be it ^^ and you’ll get the same app as i have.<\/p>\n

Since Jersey has so many features (a lot more than the JAX-RS spec would let you believe), i haven’t had the time to test a lot of them yet, and i think other security exceptions are probably waiting for us.<\/p>\n","protected":false},"excerpt":{"rendered":"

Update: this article is about Jersey 1.0.2, i’ll update the modifications i made for the 1.1.0-ea version soon. Jersey doesn’t run out of the box on GAE, and since i can’t wait for a new release to try RESTful services on AppEngine\/Java, let’s modify its servlet container so it will at least run basic samples. […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[10,9,8],"class_list":["post-123","post","type-post","status-publish","format-standard","hentry","category-java","tag-google-appengine","tag-jax-rs","tag-jersey"],"_links":{"self":[{"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/posts\/123","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=123"}],"version-history":[{"count":8,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/posts\/123\/revisions"}],"predecessor-version":[{"id":145,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=\/wp\/v2\/posts\/123\/revisions\/145"}],"wp:attachment":[{"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=123"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=123"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lqd.hybird.org\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=123"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}