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Eclipse Classpath Editing

Source code completion, searching, auto imports, all rely on a properly configured classpath. When you first create a project, a .classpath file is created in the project's root directory. If you created the project on an existing code-base, eclim will attempt to setup the .classpath file with any source code directories or libraries in the project.

Regardless of the state of your project you will at some point need to update the classpath. The primary method of doing so, is to directly edit the .classpath to add, update, or remove entries as needed. To help you do this, eclim provides several commands to ease the creation of new classpath entries and variables.

Note

All of the commands described below are only available while editing the .classpath file in vim.

When you write the .classpath file, Vim will issue a command to the eclim server to update the project's classpath, and will report any errors via vim's location list (:help location-list).

In addition to directly editing the .classpath file, you may also use maven's support for maintaining the eclipse classpath. For users who use ivy, eclim also provides a means to auto update the eclipse classpath when saving changes to your ivy.xml.

  • :NewSrcEntry <dir> - Adds a new entry for a source code directory relative to the project's root directory.

    <classpathentry kind="src" path="src/java"/>
    

    This command supports command completion of the directory relative to the .classpath file.

  • :NewProjectEntry <project> - Adds a new entry for a dependency on another project.

    <classpathentry exported="true" kind="src" path="/a_project"/>
    

    This command supports command completion of the project name.

  • :NewJarEntry <file> [<src_path> <javadoc_path>] - Adds a new entry for a jar file dependency. If the jar file is not in a folder under the project root, you must use an absolute path (apparent limitation with Eclipse).

    <classpathentry exported="true" kind="lib" path="lib/commons-beanutils-1.8.3.jar"/>
    

    You may optionally supply the path to the source for this jar and the entry created will include the sourcepath attribute:

    :NewJarEntry lib/commons-beanutils-1.8.3.jar lib/commons-beanutils-1.8.3-sources.jar
    
    <classpathentry kind="lib" path="lib/commons-beanutils-1.8.3.jar"
        sourcepath="lib/commons-beanutils-1.8.3-sources.jar"/>
    

    In addition to the source path you can all supply the path to the javadocs:

    :NewJarEntry lib/commons-beanutils-1.8.3.jar lib/commons-beanutils-1.8.3-sources.jar lib/commons-beanutils-1.8.3-javadoc.jar
    
    <classpathentry kind="lib" path="lib/commons-beanutils-1.8.3.jar"
        sourcepath="lib/commons-beanutils-1.8.3-sources.jar">
      <attributes>
        <attribute name="javadoc_location" value="jar:platform:/resource/my_project/lib/commons-beanutils-1.8.3-javadoc.jar"/>
      </attributes>
    </classpathentry>
    
  • :NewVarEntry <VAR/file> [<src_path> <javadoc_path>] - Just like NewJarEntry except an Eclipse "var" entry is created. When a jar entry references an absolute path, you should instead use a var entry. The var entry allows you to define a base dir as a variable (ex. USER_HOME = /home/username), and then reference files relative to that variable.

    <classpathentry exported="true" kind="var" path="USER_HOME/lib/hibernate-4.0.jar"/>
    

    This allows you to share .classpath files with other developers without each having a local copy with environment specific paths.

    To add new base classpath variables, you can edit $ECLIPSE_HOME/plugins/org.eclim_version/classpath_variables.properties

    By default, a USER_HOME variable is created that defaults to the java System property "user.home" and you can add more as needed.

    This command supports command completion of Eclipse variable names as well as the files and directories beneath the path the variable represents.

    To manage the classpath variables, eclim also provides the following commands.

    • :VariableList - Lists all the currently available classpath variables and their corresponding values.
    • :VariableCreate <name> <path> - Creates or updates the variable with the supplied name.
    • :VariableDelete <name> - Deletes the variable with the supplied name.

Source and Javadoc location

For your var and lib classpath entries, if you didn't do so when you created the entry, you can configure the location for that entry's source code and javadocs, like the example below, allowing you to jump to the source or lookup the docs of classes, etc found in that library. Note that the javadoc location must be a url, whether it be on the local file system (file:, jar:file:) or remote (http:).

<classpathentry exported="true" kind="lib" path="lib/hibernate-4.0.jar"
    sourcepath="<path>">
  <attributes>
    <attribute name="javadoc_location" value="file:<javadoc_dir>"/>
  </attributes>
</classpathentry>

Note

If your javadoc location is a jar in your workspace (in the curent project or another project), then the url must be in the form (where <project_name> is replaced with your project's name):

jar:platform:/resource/<project_name>/path/to/javadoc.jar!/

If the jar file is outside of your workspace, then it would be in the form:

jar:file:/your/absolute/path/to/javadoc.jar!/

Maven

Maven comes bundled with an Eclipse plugin that allows you to easily maintain your .classpath file based on your pom.xml (or project.xml for maven 1.x users).

Note

For additional information on the Eclipse plugin from maven, you may visit their online documentation for maven 1.x or maven 2.x.

  • Initial Setup

    To initialize maven's support for updating the eclipse classpath you first need to set the M2_REPO (or MAVEN_REPO for 1.x) classpath variable in the Eclipse workspace by executing the following command in vim:

    maven 2.x:

    :MvnRepo
    

    maven 1.x:

    :MavenRepo
    
  • Updating your .classpath

    Once you have performed the initial setup, updating the Eclipse .classpath file is as easy as executing the following at a command line:

    maven 2.x:

    mvn eclipse:eclipse
    

    maven 1.x:

    maven eclipse
    

    or in Vim:

    maven 2.x:

    :Mvn eclipse:eclipse
    

    maven 1.x:

    :Maven eclipse
    

    For maven 2.x users, eclim also provides support for auto updating the .classpath for your project every time you save your pom.xml file. Any entries found in the pom.xml that are not in the .classpath will be added, any entries that differ in version will be updated, and any stale entries deleted.

    Note

    This behavior can be disabled by adding the following setting to your vimrc:

    let g:EclimMavenPomClasspathUpdate = 0
    

    Note

    This feature simply updates the entries in your project's .classpath file, it does not download any newly added jars. When you'd like maven to download those new jars, you can run the following from the command line:

    mvn dependency:resolve
    

    or from within Vim:

    :Mvn dependency:resolve
    

Ivy

For users of ivy, eclim provides support for auto updating the .classpath for your project every time you save your ivy.xml file. Any entries found in the ivy.xml that are not in the .classpath will be added, any entries that differ in version will be updated, and any stale entries deleted.

  • Initial Setup

    Before you can start utilizing the auto updating support, you must first set the location of your ivy repository (ivy cache). This is the directory where ivy will download the dependencies to and where eclipse will then pick them up to be added to your project's classpath.

    To set the repository location you can use the :IvyRepo command which is made available when editing an ivy.xml file.

    :IvyRepo ~/.ivy2/cache/
    

    If you fail to set this prior to writing the ivy.xml file, eclim will emit an error notifying you that you first need to set the IVY_REPO variable via this command.

  • Updating your .classpath

    Once you have performed the initial setup, updating the Eclipse .classpath file is as easy as saving your ivy.xml file (:w) and letting eclim do the rest.

    Note

    This behavior can be disabled by adding the following setting to your vimrc:

    let g:EclimIvyClasspathUpdate = 0
    

    Note

    This feature will update your project's .classpath file accordingly, but it will not download any newly added jars. For that you'll need to have a target in your ant build file that will force ivy to download dependencies. Something like the example from the ivy docs:

    <target name="resolve" description="--> retrieve dependencies with ivy">
      <ivy:retrieve/>
    </target>
    

    You can then run this target from the command line:

    ant resolve
    

    or from within Vim

    :Ant resolve
    
  • Preserving manually added entries

    When utilizing the ivy support, eclim will attempt to remove any stale entries from your .classpath file. If you have some manually added entries, these may be removed as well. To prevent this you can add a classpath entry attribute notifying eclim that the entry should be preserved.

    Ex.

    <classpathentry kind="lib" path="lib/j2ee-1.4.jar">
      <attributes>
        <attribute name="eclim.preserve" value="true"/>
      </attributes>
    </classpathentry>