Adding a group of class files to a project's classpath tells the IDE which
classes the project should have access to during compilation and execution.
The IDE also uses classpath settings to enable code completion, automatic highlighting
of compilation errors, and refactoring.
Source roots must only exist in a single project and
cannot be shared with other projects, regardless of whether they are opened
or not. If you need to use a library in several projects, create a special
project within which to store it.
Classpath and Standard Projects
For
, the IDE maintains separate classpaths for compiling and running your
project, as well as compiling and running JUnit tests. The IDE automatically adds
everything on your project's compilation classpath to the project's runtime classpath.
Whenever you build a for which a main class is specified, the IDE automatically copies any JAR
files on the project's classpath to the dist/lib folder.
The IDE also adds each of the JAR files
to the Class-Path element in the application JAR's manifest.mf
file. This simplifies running the application outside the IDE. For more
information, see Preparing
a JAR for Deployment Outside the IDE
To edit a standard project's classpath:
Expand the project node, right-click the Libraries node, and choose Properties.
In the Project Properties dialog box, add the necessary elements to the project's compilation classpath by clicking
the appropriate button. You can add any of the following:
Project. The JAR file or
WAR file produced by another project, as well as the associated source
files and Javadoc documentation.
Library. A collection of JAR
files or folders with compiled classes, which can optionally have associated
source files and Javadoc documentation.
JAR/Folder. A JAR file or folder that contains compiled classes.
(Optional) In web applications, click the Deploy checkbox if you do not want to
package an element in the web application. By default, all classpath elements are included in
the web application.
(Optional) Click the Build Projects on Classpath checkbox if you do not want to
rebuild all projects on the classpath whenever you build the current project. By default, all projects on the classpath and, in
web applications, projects listed in the Packaging page, are rebuilt when you build the current project.
(Optional) Click the Move Up and Move Down buttons to alter the
classpath priority.
(Optional) Click the Run, Compile Tests, or Run Tests tabs to make any
changes to the these classpaths.
You can also add dependent projects and other required resources to a project by simply right-clicking the
Libraries node in the Projects window and choosing the appropriate item (Project, Library, or JAR/Folder) from the contextual menu.
Classpath and Free-Form Projects
In
, your Ant script handles the classpath for all of your source
folders. The classpath settings for free-form projects only tell the IDE
what classes to make available for code completion and refactoring. In order
to change a free-form project's actual compilation or runtime classpath you
must edit your build.xml file directly.
Note that free-form projects do not have Library nodes nor do free-form project's
Project Properties dialog boxes include a Libraries panel. For more information,
see Declaring the Classpath in
Free-Form Projects.
The project's classpath declaration must exactly match the classpath
used by your Ant script.