For the latest version or to report bugs visit: https://freemarker.apache.org/

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FreeMarker is a "template engine"; a generic tool to generate text output (anything from HTML to auto generated source code) based on templates. It's a Java package, a class library for Java programmers. It's not an application for end-users in itself, but something that programmers can embed into their products. FreeMarker is designed to be practical for the generation of HTML Web pages, particularly by servlet-based applications following the MVC (Model View Controller) pattern.

FreeMarker is licensed under the Apache License, Version 2.0.

See the LICENSE file for more details!

Online: https://freemarker.apache.org/docs/

Offline: The full documentation is available in the binary distribution in the documentation/index.html directory.

If you are using Maven, just add this dependency:

  <!--
  Attention: Be sure nothing pulls in an old dependency with groupId
  "freemarker" (without the "org."), because then you will end up with
  two freemarker.jar-s and unpredictable behavior on runtime!
  -->
  <dependency>
    <groupId>org.freemarker</groupId>
    <artifactId>freemarker</artifactId>
    <version>{version}</version>
  </dependency>

Otherwise simply copy freemarker.jar to a location where your Java application's ClassLoader will find it. For example, if you are using FreeMarker in a web application, you probably want to put freemarker.jar into the WEB-INF/lib directory of your web application.

FreeMarker has no required dependencies. It has several optional dependencies, but usually you don't have to deal with them, because if you are using an optional feature that's certainly because your application already uses the related library.

Attention: If you upgrade to OpenJDK 9 or later, and you are using XPath queries in templates, you will need to add Apache Xalan as a dependency, as freemarker.ext.dom can't use the XPath support included in OpenJDK anymore. It's not needed on Oracle Java 9, or if FreeMarker is configured to use Jaxen for XPath.

The minimum required Java version is currently Java SE 7. (The presence of a later version may be detected on runtime and utilized by FreeMarker.)

Online (for stable releases only): https://freemarker.apache.org/docs/app_versions.html

Offline: In the binary release, open documentation/index.html, and you will find the link.

If you haven't yet, download the source release, or checkout FreeMarker from the source code repository. See repository locations here: https://freemarker.apache.org/sourcecode.html

You need JDK 8 (not JDK 9!), Apache Ant (tested with 1.9.6) and Ivy (tested with 2.5.0) to be installed. To install Ivy (but be sure it's not already installed), issue ant download-ivy; it will copy Ivy under ~/.ant/lib. (Alternatively, you can copy ivy-<version>.jar into the Ant home lib subfolder manually.)

It's recommended to copy build.properties.sample into build.properties, and edit its content to fit your system. (Although basic jar building should succeeds without the build.properties file too.)

To build freemarker.jar, just issue ant in the project root directory, and it should download all dependencies automatically and build freemarker.jar. (Depencies will be cached into the .ivy/cache subdirectory of the project.)

To test your build, issue ant test.

To generate documentation, issue ant javadoc and ant manualOffline.

Do these first, regardless of which IDE you are using:

• Install Ant and Ivy, if you haven't yet; see earlier.

• From the command line, run ant clean jar ide-dependencies (Note that now the folders ide-dependencies, build/generated-sources and META-INF were created.)

Below you find the step-by-step setup for Eclipse (originally done on Mars.1):

• Start Eclipse
• You may prefer to start a new workspace (File -> "Switch workspace"), but it's optional.
• Window -> Preferences
  • General -> Workspace, set the text file encoding to "UTF-8". (Or, you can set the same later on project level instead.)
  • General -> Editors -> Text Editors, set:
    • Insert space for tabs
    • Show print margin, 120 columns
  • Java -> Code Style -> Formatter -> Import... Select src\ide-settings\Eclipse\Formatter-profile-FreeMarker.xml inside the FreeMarker project directory. (On IntelliJ IDEA, import src/ide-settings/IntelliJ-IDEA/Java-code-style-FreeMarker.xml instead) This profile uses space-only indentation policy and 120 character line width, and formatting rules that are pretty much standard in modern Java.
  • Java -> Code Style -> Organize imports (On IntelliJ IDEA, this was already configured by the Java code style import earlier.) The order is this (the Eclipse default): java, javax, org, com. Number of imports required for .: 99 Number of static imports needed for .: 1
  • Java -> Installed JRE-s: Ensure that you have JDK 8 installed, and that it was added to Eclipse. Note that it's not JRE, but JDK.
  • Java -> Compiler -> Javadoc: "Malformed Javadoc comments": Error "Only consider members as visible": Private "Validate tag arguments": true "Missing tag descriptions": Validate @return tags "Missing Javadoc tags": Ignore "Missing Javadoc comments": Ignore
• Create new "Java Project" in Eclipse:
  • In the first window popping up:
    • Change the "location" to the directory of the FreeMarker project
    • Press "Next"
  • In the next window, you see the build path settings:
    • On "Source" tab, ensure that exactly these are marked as source directories (be careful, Eclipse doesn't auto-detect these well): build/generated-sources/java src/main/java, src/main/resources, src/test/java, src/test/resources
    • On the "Libraries" tab:
      • Delete everyhing from there, except the "JRE System Library [...]"
      • Edit "JRE System Library [...]" to "Execution Environment" "JavaSE 1.8"
      • Add all jar-s that are directly under the "ide-dependencies" directory (use the "Add JARs..." and select all those files).
  • Press "Finish"
• Eclipse will indicate many errors at this point; it's expected, read on.
• Project -> Properties -> Java Compiler
  • Set "Compiler Compliance Level" to "1.7" (you will have to uncheck "Use compliance from execution environment" for that)
  • In Errors/Warnings, check in "Enable project specific settings", then set "Forbidden reference (access rules)" from "Error" to "Warning".
• You will still have errors on these java files (because different java files depend on different versions of the same library, and Eclipse can't handle that). Exclude those java files from the Build Path (in the Package Explorer, right click on the problematic file -> "Build Path" -> "Exclude"): _Jython20*.java, _Jython22*.java, _FreeMarkerPageContext2.java, FreeMarkerJspFactory2.java, Java8*.java Also, close these files if they are open. Now you shouldn't have any errors.
• At Project -> Properties -> Java Code Style -> Formatter, check in "Enable project specific settings", and then select "FreeMarker" as active profile.
• At Project -> Properties -> Java Editor -> Save Actions, check "Enable project specific settings", then "Perform the selected actions on save", and have only "Organize imports" and "Additional actions" checked (the list for the last should contain "Add missing @Override annotations", "Add missing @Override annotations to implementations of interface methods", "Add missing @Deprecated annotations", and "Remove unnecessary cast").
• Right click on the project -> Run As -> JUnit Test It should run without problems (all green).
• It's highly recommended to use the Eclipse FindBugs plugin.
  • Install it from Eclipse Marketplace (3.0.1 as of this writing)
  • Window -> Preferences -> Java -> FindBugs: Set all bug marker ranks from Warning to Error. (For false alarms we add @SuppressFBWarnings(value = "...", justification = "...") annotations.)
  • Project -> Properties -> FindBugs -> [x] Run Automatically
  • There should 0 errors. But sometimes the plugin fails to take the @SuppressFBWarnings annotations into account; then use Project -> Clean.

Originally done on IntelliJ IDEA Community 2018.2.4:

• "New" -> "Project". In order as the IntelliJ will prompt you:

  • Select "Java" on the left side, and "1.8" for SDK on the right side. Press "Next".

  • Template selection: Don't chose anything, "Next"

  • Project name: "FreeMarker-2.3-gae". Project location: Wherever you have checked out the 2.3-gae branch from Git. Press "Finish"

• Open your newly created "FreeMarker-2.3-gae" project

• "File" -> "Project Structure..."

  • Select "Modules" (on the left) / "Sources" (tab on the right). Now you see a Content Root that was automatically added (at the rightmost side, under the "Add Content Root" button). Remove it (click the "X" next to it); no Content Root should remain. Now "Add Content Root", and select the FreeMarker project folder. IntelliJ will now add the new Content Root, and automatically add some "Source Folders" and maybe some more under it, but it won't be correct, so edit it until your newly added Source Root has this content:

    • Source Folders:
      src/main/java,
      build/generated-sources/java [generated]

    • Test Source folders:
      src/test/java

    • Resource Folders:
      src/main/resources

    • Test Resource Folders:
      src/test/resources

  • Still inside the "Sources" tab, change the "Language level" to "7". (Yes, we use Java 8 SDK with language level 7 in the IDE, due to the tricks FreeMarker uses to support different Java versions.)

  • Switch over to the "Dependencies" tab (still inside "Project Structure" / "Modules"), and add all the jar-s inside the ide-dependencies directory as dependency. (How: Click the "+" icon at the right edge, select "JARs or directory", navigate to ide-dependencies directory, expand it, then range-select all the jars in it. Thus you add all of them at once.) After all jar-s were added, find dom4j-*.jar in the table, and move it to the bottom of the table (otherwise it shadows some Jaxen classes with a too old version).

• "File" -> "Settings" -> "Build, Execution, Deployment" -> "Compiler" -> "Excludes": Add source files that match these (you simply find them manually, and add their absolute path):
  _Jython20*.java,
  _Jython22*.java,
  _FreeMarkerPageContext2.java,
  FreeMarkerJspFactory2.java,
  Java8*.java

• You may do "Build" / "Build project" (Ctrl+F9) to see if everything compiles now.

• "File" -> "Settings"

  • Under "Editor" / "Code style", import and use freemarker/src/ide-settings/IntelliJ-IDEA/Java-code-style-FreeMarker.xml
  • Under "Editor" / "Inspections", import and use freemarker/src/ide-settings/IntelliJ-IDEA/Editor-Inspections-FreeMarker.xml
  • Copy the copyright header comment from some of the java files, then under "Editor" / "Copyright" / "Copyright Profiles" click "+", enter "ASL2" as name, then paste the copyright header. Delete the /* and */ lines, and the * prefixes (to select columns of text, hold Alt while selecting with the mouse.) Then go back to "Copyright" in the tree, and set "Default project copyright" to "ASL2".