Installing FreeMarker

There are two pieces to install with FreeMarker. One is the server side code needed to allow the servlets to run template files. The other is the Eclipse plugin that provides support for writing template files.

Let's start with the plugin (you remember installing all those plugins earlier, right?). Go to this page and copy the link for the version of Eclipse you have (use the Stable Updates links). Install just the FreeMarker IDE from that site.

Restart Eclipse at the end, and we'll move on to the FreeMarker server libraries. Download the latest stable version at the FreeMarker download page. Unzip the file onto your desktop, and look for lib/freemarker.jar (the rest of the zip file is documentation that you may want to keep).

Copy freemarker.jar into the war/WEB-INF/lib directory of your project in Eclipse. Right click on the file, choose Build Path->Add to Build Path.

That's it, we can now both create template files and execute them from servlets. We'll see how in the next few posts.

UPDATE: If you're using more recent versions of GAE and Freemarker than are installed in the labs (very likely if you've installed the latest versions at home), there might be a conflict between them. If you get an error message when compiling code that uses Freemarker templates about TreeNode being a restricted class, then you have the versions that are not compatible.

There's a workaround here. The workaround is to to create a TextBlock.java file in the freemarker.core package (the thread linked to gives the code you put into that file). If you got it right, you should see, under your src directory in Eclipse, a freemarker.core package (at the same level as your project.server and project.client packages).

Note that to successfully copy the code from the thread, you need to click the Read More link at the bottom of that message (since not all the code shows in the thread view). Then, after you paste the code into Eclipse, you'll get some errors because of line wrapping in the thread. Just back the offending lines onto the end of the previous line to remove the wrapping, and it'll compile.

Eventually, this will be fixed in one way or another (probably with a Freemarker update), and your version of TextBlock.java can be removed.