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| <title>Java Build Path</title> |
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| <body> |
| <h1>Java Build Path</h1> |
| |
| <p>The options in this page indicate the build path settings for a Java project. You can reach this page through the project properties (Project > Properties > Java Build Path) from the context menu on a created project or the <a href="ref-menu-file.htm">File |
| menu</a> of the workbench.</p> |
| |
| <p>The build class path is a list of paths visible to the compiler when building the project.</p> |
| |
| <p>For projects targeting Java 9 or greater, entries on the <a href="#projects">Projects</a> and <a href="#libraries">Libraries</a> tabs |
| can be placed either on the traditional Classpath or on the Modulepath. |
| Entries on the Modulepath are interpreted as <strong>modules</strong> according to the |
| <a href="http://openjdk.java.net/projects/jigsaw/spec">Java Platform Module System</a>. |
| For these, further details can be edited via <a href="propertypages/ref-properties-buildpath-modularity.htm">Modularity Details</a>. |
| </p> |
| |
| <p>This property page consists of the following tabs:</p> |
| <ul> |
| <li><a href="#source">Source tab</a></li> |
| <li><a href="#projects">Projects tab</a></li> |
| <li><a href="#libraries">Libraries tab</a></li> |
| <li><a href="#order-and-export">Order and Export tab</a></li> |
| <li><a href="#module-dependencies">Module Dependencies tab</a></li> |
| </ul> |
| |
| <h2 id="source">Source tab</h2> |
| |
| <p>Source folders are top-level folders in the project hierarchy. They are the root of packages containing .java files. |
| The compiler will translate the contained files to .class files that will be written to the output folder.</p> |
| <p>Source folders allow to structure the project, for example to separate |
| test from the application in two source folders. Within a source folder, a more detailed structuring can be achieved by using packages.</p> |
| <p>Each source folder can define an exclusion filter to specify which |
| resources inside the folder should not be visible to the compiler.</p> |
| <p>Resources existing in source folders are copied to the output folder unless the setting in the <a href="preferences/java/compiler/ref-preferences-building.htm">Java > Compiler > Building</a> preference |
| page specifies that the resource is filtered. The output folder is defined per project except if a source folder specifies its own output folder.</p> |
| |
| <table border="1" cellspacing="0" cellpadding="5" summary="Source folder options" width="600"> |
| <caption>Source folder options:<br> |
| </caption> |
| |
| <tbody> |
| <tr> |
| <th>Option</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top" width="20%">Add Folder</td> |
| |
| <td align="left" valign="top">Creates a new folder to contain source</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top" width="20%">Link Source</td> |
| |
| <td align="left" valign="top">Creates a new folder that links to an location outside of the workspace</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top">Edit or Toggle</td> |
| |
| <td align="left" valign="top">Allows to modify the currently selected |
| source folder or source folder attribute.</td> |
| </tr> |
| |
| <tr> |
| <td>Remove</td> |
| |
| <td>Removes the selected folders from the class path. This does not |
| delete the folders nor their contents.</td> |
| </tr> |
| <tr> |
| <td>Allow output folder per source folder</td> |
| <td>Shows/Hides the 'output folder' attribute of the source folders</td> |
| </tr> |
| |
| </tbody> |
| </table> |
| <br> |
| <table border="1" cellspacing="0" cellpadding="5" summary="Source folder attributes" width="600"> |
| <caption>Source folder attributes:<br> |
| </caption> |
| |
| <tbody> |
| <tr> |
| <th>Attribute</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top" width="20%">Exclusion filter</td> |
| |
| <td align="left" valign="top">Selects which resources are not visible to the compiler. For details see <a href="../concepts/concept-inclusion-exclusion-patterns.htm">Inclusion and exclusion patterns</a>.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Output folder</td> |
| |
| <td align="left" valign="top">Only available when <b>Allow output |
| folder per source folder</b> is checked. Defines a source folder specific output location. If not set the project's default output folder is used.</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top">Native library location</td> |
| <td align="left" valign="top">Defines the folder that contains the native libraries |
| (for example 'dll' or 'o' files) required at runtime by the sources in the source folder. |
| </td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Ignore optional compile problems</td> |
| <td align="left" valign="top">When set to 'Yes', all optional problems will not be reported by the compiler.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Contains test sources</td> |
| <td align="left" valign="top">When set to 'Yes', the sources in the folder are assumed to be test code, |
| otherwise main code. When compiling main code, only other main code (from the current project or from other projects on the build path) is visible and only dependencies |
| that are not configured to be visible for test code only. When compiling test code, all code on build path |
| is visible. When compiling test code with Java 9, the unnamed module is assumed to be readable |
| by the current module, so test dependencies that should not be mentioned in the <code>module-info.java</code> are accessible if they are put |
| on the classpath.</td> |
| </tr> |
| </tbody> |
| </table> |
| |
| <p>At the bottom of this page, the <b>Default output folder</b> field allows you to enter a path to a folder path where the compilation output for this |
| project will reside. The default output is used for source folders that do not specify an own output folder. Use <b>Browse</b> to select an existing location from the current project.</p> |
| |
| <h2 id="projects">Projects tab</h2> |
| |
| <p>In the <b>Required projects on the build path</b> list, you can add project dependencies by selecting other workbench |
| projects to add to the build path for this new project.</p> |
| |
| <p>Adding a required project indirectly adds all its classpath entries marked as 'exported'. Setting a classpath entry as exported is done in the Order and Export tab.</p> |
| |
| <p>The projects selected here are automatically added to the referenced projects list. The referenced project list is used to determine the build order. A project is always |
| build after all its referenced projects are built.</p> |
| |
| <table border="1" cellspacing="0" cellpadding= "5" summary="Project entry options" width="600"> |
| |
| <tbody> |
| <tr> |
| <th>Action</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="middle" width="20%">Add</td> |
| |
| <td align="left" valign="top">Add another project in the workspace to the build path of this project.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="middle" width="20%">Edit or Toggle</td> |
| |
| <td align="left" valign="top">Edit the classpath attribute of a required project.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="middle" width="20%">Remove</td> |
| |
| <td align="left" valign="top">Removes the selected required projects from the list.</td> |
| </tr> |
| |
| </tbody> |
| </table> |
| <table border="1" cellspacing="0" cellpadding="5" summary="Project entry attributes" |
| width="600"> |
| <caption>Project entry attributes:<br> |
| </caption> |
| |
| <tbody> |
| <tr> |
| <th>Attribute</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Native library location</td> |
| |
| <td align="left" valign="top">Specifies where native library required for the project to operate can be found.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Is modular / Is not modular</td> |
| |
| <td align="left" valign="top">Specifies whether the project should be treated as a module. |
| Double-click to edit <a href="propertypages/ref-properties-buildpath-modularity.htm">Modularity Details</a>.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Access rules</td> |
| |
| <td align="left" valign="top">Specifies access rules for project contained in the library. This allows to hide content of a project.</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top">Visible only for test sources</td> |
| <td align="left" valign="top">When set to 'Yes', the code reachable via the referenced project is only accessible when sources in sources folder marked to contain test code are compiled.</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top">Without test code</td> |
| <td align="left" valign="top">When this is set to 'No', test code from the referenced project is not visible when compiling test code in the current project.</td> |
| </tr> |
| </tbody> |
| </table> |
| |
| <h2 id="libraries">Libraries tab</h2> |
| |
| <p>On this page, you can add libraries to the build path.</p> |
| <p>By default, the library list contains an entry representing the Java runtime library. This entry points to the JRE |
| selected as the default JRE. The default JRE is configured in the <a href="preferences/java/debug/ref-installed_jres.htm">Java > Debug > Installed JREs</a> preferences page.</p> |
| |
| <table border="1" cellspacing="0" cellpadding= "5" summary="Libraries tab options" width="600"> |
| <caption> |
| Libraries tab options:<br> |
| </caption> |
| |
| <tbody> |
| <tr> |
| <th width="20%">Option</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Add JARs</td> |
| |
| <td align="left" valign="top">Allows you to navigate the workbench hierarchy and select JAR files to add to the build path.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Add External JARs</td> |
| |
| <td align="left" valign="top">Allows you to navigate the file system (outside the workbench) and select JAR files to add to the build path.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Add Variable</td> |
| |
| <td align="left" valign="top">Allows you to add classpath variables to the build path. Classpath variables are an indirection to JARs with the benefit of avoiding local |
| file system paths in a classpath. This is needed when projects are shared in a team.<br> |
| Variables can be created and edited in the <a href="preferences/java/buildpath/ref-preferences-classpath-variables.htm">Java > Build Path > Classpath Variables</a> preference page.</td> |
| </tr> |
| |
| <tr> |
| <td>Add Library</td> |
| |
| <td>Allows to add a predefined libraries like the JRE System Library. Such libraries can stand for an arbitrary number of entries (visible as children node of the library node)</td> |
| </tr> |
| |
| <tr> |
| <td>Add Class Folder</td> |
| |
| <td>Allows to navigate the workbench hierarchy and select a class folder for the build path. The selection dialog also allows you to create a new folder.</td> |
| </tr> |
| |
| <tr> |
| <td>Add External Class Folder</td> |
| |
| <td>Allows to navigate the file system (outside the workbench) and select a class folder for the build path. The selection dialog also allows you to create a new folder.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Edit or Toggle</td> |
| |
| <td align="left" valign="top">Allows you to modify the currently selected library entry or entry attribute</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Remove</td> |
| |
| <td align="left" valign="top">Removes the selected element from the build path. This does not delete the resource.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Migrate JAR File</td> |
| |
| <td align="left" valign="top">Migrate a JAR on the build path to a newer version. If the newer version contains refactoring scripts |
| the refactoring stored in the script will be executed.</td> |
| </tr> |
| </tbody> |
| </table> |
| |
| <p> Libraries have the following attributes (presented as library entry children nodes):</p> |
| |
| <table border="1" cellspacing="0" cellpadding="5" summary="Library entry attributes" |
| width="600"> |
| <caption>Library entry attributes:<br> |
| </caption> |
| |
| <tbody> |
| <tr> |
| <th>Attribute</th> |
| |
| <th>Description</th> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Source attachment</td> |
| |
| <td align="left" valign="top">Specifies where the library's source can be found.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top" width="20%">Javadoc location</td> |
| |
| <td align="left" valign="top">Specifies where the library's Javadoc documentation can be found. If specified you can use <b>Shift+F2</b> on an element of this library to open its documentation.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top" width="20%">External annotations</td> |
| |
| <td align="left" valign="top">Specifies where <a href="../tasks/task-using_external_null_annotations.htm">external annotations</a> for the library can be found. |
| If specified these annotations will be considered by JDT for its static null analysis.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Native library location</td> |
| |
| <td align="left" valign="top">Specifies where native library required for the library to operate can be found.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Is modular / Is not modular</td> |
| |
| <td align="left" valign="top">Specifies whether the library should be treated as a module (or several modules). |
| Double-click to edit <a href="propertypages/ref-properties-buildpath-modularity.htm">Modularity Details</a>.</td> |
| </tr> |
| |
| <tr> |
| <td align="left" valign="top">Access rules</td> |
| |
| <td align="left" valign="top">Specifies access rules for resources contained in the library. This allows to hide content of a library.</td> |
| </tr> |
| <tr> |
| <td align="left" valign="top">Visible only for test sources</td> |
| <td align="left" valign="top">When set to 'Yes', the code in the referenced library is only accessible when sources in source folders marked to contain test code are compiled.</td> |
| </tr> |
| </tbody> |
| </table> |
| |
| <h2 id="order-and-export">Order and Export tab</h2> |
| |
| <p>In the <b>Build class path order</b> list, you can click the <b>Up</b> and <b>Down</b> buttons to move the selected path entry up or down in the build path order for this new project.</p> |
| |
| <p>Checked list entries are marked as exported. Exported entries are visible to projects that require the project. Use the <b>Select |
| All</b> and <b>Deselect All</b> to change the checked state of all entries. Source folders are always exported, |
| and can not be deselected.</p> |
| |
| <h2 id="module-dependencies">Module Dependencies tab</h2> |
| <p>For projects targeting Java 9 or greater this page visualizes module-related aspects of all dependencies of the current project. |
| At the left the <b>All Modules</b> list shows all modules that are considered when building the current projects. |
| At the right <b>Details</b> of a selected module are shown, along with buttons to modify these details.</p> |
| |
| <p>The <b>All Modules</b> list uses the following icon decorations to distinguish different kinds of modules:</p> |
| <table border="1" cellspacing="0" cellpadding="5" summary="Module decorations"> |
| <tbody> |
| <tr><th>Decorated Icon</th><th>Meaning</th></tr> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/focus_module.svg" alt="focus module" width="30"></td> |
| <td>The <b>focus</b> module, i.e., the module implemented by the current project. |
| This module will always be shown at the top of the list, followed by other modules |
| in alphabetical order.</td> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/system_module.svg" alt="system module" width="30"></td> |
| <td>A <b>system</b> module, i.e., a module provided by the Java System Library.</td> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/auto_module.svg" alt="automatic module" width="30"></td> |
| <td>An <b>automatic</b> module, i.e., a module that is not declared using <code>module-info.java</code>, |
| but inferred from information like the file name of a jar archive, or an attribute in <code>MANIFEST.MF</code> |
| and the list of contained, non-empty packages.</td> |
| </tbody> |
| </table> |
| <p>Operations offered for the All Modules list:</p> |
| <ul> |
| <li>You may remove one or more System modules by selecting the respective modules and clicking the <b>Remove</b> |
| button at the right. Note, that other modules need to be removed from the build path on the respective |
| Projects or Libraries tab.</li> |
| <li>If the current project lacks file <code>module-info.java</code>, i.e., types in the project are associated |
| with the "unnamed module", then by default only a subset of System modules is considered. In this case |
| you can pull in more System modules by clicking the <b>Add System Module...</b> button.</li> |
| </ul> |
| <p><em>Modules that have just been added to the Modulepath on the corresponding tab of this page, |
| will not be visible in this list immediately. |
| In this case you need to click <b>Apply</b> to update the All Modules list.</em></p> |
| |
| <p>The <b>Details</b> tree has two root nodes:</p> |
| <ul> |
| <li>under the top node <b>Declared details of <i>modulename</i></b> |
| you can find those details that are declared in the select module's description, namely representations |
| of all <b>requires</b>, <b>exports</b> and <b>opens</b> declarations.</li> |
| <li>under <b>Configured details</b> additional properties of the selected module can be configured.</li> |
| </ul> |
| |
| <p>The elements in this part of the page are marked with one of the following decorated icons:</p> |
| <table border="1" cellspacing="0" cellpadding="5" summary="Detail icons and decorations"> |
| <tbody> |
| <tr><th>Decorated Icon</th><th>Meaning</th></tr> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/reads_module.svg" alt="reads module" width="30"></td> |
| <td>A module which the selected module <b>reads</b>. This corresponds to a <b>requires</b> declaration.</td> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/exports_packages.svg" alt="exports package" width="30"></td> |
| <td>A package which the selected module <b>exports</b> to other modules, possibly qualified with a list |
| of modules to which the package is <i>exclusively</i> exported. |
| This corresponds to an <b>exports</b> or <b>exports _ to</b> declaration.</td> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/opens_package.svg" alt="opens package" width="30"></td> |
| <td>A package which the selected module <b>opens</b> to other modules (for reflection), |
| possibly qualified with a list of modules to which the package is <i>exclusively</i> opened. |
| This corresponds to an <b>opens</b> or <b>opens _ to</b> declaration.</td> |
| <tr><td><img src="../images/org.eclipse.jdt.ui/combined/patch_project.svg" alt="patches module" width="30"></td> |
| <td>A project (or source folder) that <b>patches</b> the selected module, i.e., |
| all types in that project (or source folder) will be <i>associated with</i>, |
| and compiled as part of the selected module.</td> |
| </tbody> |
| </table> |
| |
| <p>Operations offered for the Details tree, provided that a module has been selected in the All Modules list:</p> |
| <ul> |
| <li>By clicking <b>Read Module...</b> you can create a new dependency from the select module to one or more other modules.</li> |
| <li>By clicking <b>Expose Package...</b> you can define that the selected module <b>exports</b> or |
| <b>opens</b> one of its packages. The dialog that opens when you click this button supports code completion |
| for selecting a package and also has a field where a list of target modules can be specified.</li> |
| <li>By double clicking an existing <b>exports</b> or <b>opens</b> node you can edit its details. |
| The same can also be done by clicking the <b>Edit...</b> button.</li> |
| <li>By clicking <b>Patch with...</b> you can select a project or source folder for patching the selected module.</li> |
| <li>Any node under the <b>Configured details</b> node can be removed by clicking <b>Remove</b></li> |
| <li>Everything that has been configured in this tab can be translated into a set of command line options |
| as specified by the Java Platform Module System (JPMS). |
| To do so click the <b>Show JPMS Options...</b> button.<br> |
| These options could be used for invoking a compiler from the command line, |
| or as runtime options when launching the program, to ensure that the JVM |
| will see the same module graph that has been configured here.</li> |
| </ul> |
| |
| <h3 class="related">Related concepts</h3> |
| <a href="../concepts/concept-build-classpath.htm">Build classpath</a><br> |
| <a href="../concepts/concept-classpath-variables.htm">Classpath variables</a><br> |
| <a href="../concepts/concept-inclusion-exclusion-patterns.htm">Inclusion and exclusion patterns</a> |
| <h3 class="related">Related references</h3> |
| <a href="../reference/propertypages/ref-properties-buildpath-modularity.htm">Modularity details <i>(deprecated)</i></a><br> |
| <a href="../reference/ref-jdt-faq.htm">Frequently asked questions on JDT</a><br> |
| <a href="../reference/preferences/java/buildpath/ref-preferences-classpath-variables.htm">Classpath variables preferences</a><br> |
| <a href="../reference/preferences/java/ref-preferences-build-path.htm">Build path preferences</a><br> |
| <a href="../reference/preferences/java/ref-preferences-compiler.htm">Compiler preferences</a> |
| </body> |
| </html> |
| |
