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- <html>
-
- <head>
- <meta http-equiv="Content-Language" content="en-us">
- <link rel="stylesheet" type="text/css" href="stylesheets/style.css">
- <title>Writing a Simple Buildfile</title>
- </head>
-
- <body>
- <h1>Using Apache Ant</h1>
- <h2><a name="buildfile">Writing a Simple Buildfile</a></h2>
- <p>Apache Ant's buildfiles are written in XML. Each buildfile contains one project
- and at least one (default) target. Targets contain task elements.
- Each task element of the buildfile can have an <code>id</code> attribute and
- can later be referred to by the value supplied to this. The value has
- to be unique. (For additional information, see the
- <a href="#tasks"> Tasks</a> section below.)</p>
- <h3><a name="projects">Projects</a></h3>
- <p>A <i>project</i> has three attributes:</p>
- <table border="1" cellpadding="2" cellspacing="0">
- <tr>
- <td valign="top"><b>Attribute</b></td>
- <td valign="top"><b>Description</b></td>
- <td align="center" valign="top"><b>Required</b></td>
- </tr>
- <tr>
- <td valign="top">name</td>
- <td valign="top">the name of the project.</td>
- <td align="center" valign="top">No</td>
- </tr>
- <tr>
- <td valign="top">default</td>
- <td valign="top">the default target to use when no target is supplied.</td>
- <td align="center" valign="top">No; however, <b>since Ant 1.6.0</b>,
- every project includes an implicit target that contains any and
- all top-level tasks and/or types. This target will always be
- executed as part of the project's initialization, even when Ant is
- run with the <a href="running.html#options">-projecthelp</a> option.
- </td>
- </tr>
- <tr>
- <td valign="top">basedir</td>
- <td valign="top">the base directory from which all path calculations are
- done. This attribute might be overridden by setting
- the "basedir"
- property beforehand. When this is done, it must be omitted in the
- project tag. If neither the attribute nor the property have
- been set, the parent directory of the buildfile will be used.<br/>
- A relative path is resolved relative to the directory containing
- the build file.
- </td>
- <td align="center" valign="top">No</td>
- </tr>
- </table>
- <p>Optionally, a description for the project can be provided as a
- top-level <code><description></code> element (see the <a
- href="Types/description.html">description</a> type).</p>
-
- <p>Each project defines one or more <i>targets</i>.
- A target is a set of <i>tasks</i> you want
- to be executed. When starting Ant, you can select which target(s) you
- want to have executed. When no target is given,
- the project's default is used.</p>
-
- <h3><a name="targets">Targets</a></h3>
- <p>A target can depend on other targets. You might have a target for compiling,
- for example, and a target for creating a distributable. You can only build a
- distributable when you have compiled first, so the distribute target
- <i>depends on</i> the compile target. Ant resolves these dependencies.</p>
- <p>It should be noted, however, that Ant's <code>depends</code> attribute
- only specifies the <i>order</i> in which targets should be executed - it
- does not affect whether the target that specifies the dependency(s) gets
- executed if the dependent target(s) did not (need to) run.
- </p>
-
- <p>More information can be found in the
- dedicated <a href="targets.html">manual page</a>.</p>
-
- <h3><a name="tasks">Tasks</a></h3>
- <p>A task is a piece of code that can be executed.</p>
- <p>A task can have multiple attributes (or arguments, if you prefer). The value
- of an attribute might contain references to a property. These references will be
- resolved before the task is executed.</p>
- <p>Tasks have a common structure:</p>
- <blockquote>
- <pre><<i>name</i> <i>attribute1</i>="<i>value1</i>" <i>attribute2</i>="<i>value2</i>" ... /></pre>
- </blockquote>
- <p>where <i>name</i> is the name of the task,
- <i>attributeN</i> is the attribute name, and
- <i>valueN</i> is the value for this attribute.</p>
- <p>There is a set of <a href="tasklist.html" target="navFrame">built-in tasks</a>, but it is also very
- easy to <a href="develop.html#writingowntask">write your own</a>.</p>
- <p>All tasks share a task name attribute. The value of
- this attribute will be used in the logging messages generated by
- Ant.</p>
- Tasks can be assigned an <code>id</code> attribute:
- <blockquote>
- <pre><<i>taskname</i> id="<i>taskID</i>" ... /></pre>
- </blockquote>
- where <i>taskname</i> is the name of the task, and <i>taskID</i> is
- a unique identifier for this task.
- You can refer to the
- corresponding task object in scripts or other tasks via this name.
- For example, in scripts you could do:
- <blockquote>
- <pre>
- <script ... >
- task1.setFoo("bar");
- </script>
- </pre>
- </blockquote>
- to set the <code>foo</code> attribute of this particular task instance.
- In another task (written in Java), you can access the instance via
- <code>project.getReference("task1")</code>.
- <p>
- Note<sup>1</sup>: If "task1" has not been run yet, then
- it has not been configured (ie., no attributes have been set), and if it is
- going to be configured later, anything you've done to the instance may
- be overwritten.
- </p>
- <p>
- Note<sup>2</sup>: Future versions of Ant will most likely <i>not</i>
- be backward-compatible with this behaviour, since there will likely be no
- task instances at all, only proxies.
- </p>
-
- <h3><a name="properties">Properties</a></h3>
-
- <p>Properties are an important way to customize a build process or
- to just provide shortcuts for strings that are used repeatedly
- inside a build file.</p>
-
- <p>In its most simple form properties are defined in the build file
- (for example by the <a href="Tasks/property.html">property</a>
- task) or might be set outside Ant. A property has a name and a
- value; the name is case-sensitive. Properties may be used in the
- value of task attributes or in the nested text of tasks that support
- them. This is done by placing the property name between
- "<code>${</code>" and "<code>}</code>" in the
- attribute value. For example, if there is a "builddir"
- property with the value "build", then this could be used
- in an attribute like this: <code>${builddir}/classes</code>. This
- is resolved at run-time as <code>build/classes</code>.</p>
-
- <p>With Ant 1.8.0 property expansion has become much more powerful
- than simple key value pairs, more details can be
- found <a href="properties.html">in the concepts section</a> of this
- manual.</p>
-
- <h3><a name="example">Example Buildfile</a></h3>
- <pre>
- <project name="MyProject" default="dist" basedir=".">
- <description>
- simple example build file
- </description>
- <!-- set global properties for this build -->
- <property name="src" location="src"/>
- <property name="build" location="build"/>
- <property name="dist" location="dist"/>
-
- <target name="init">
- <!-- Create the time stamp -->
- <tstamp/>
- <!-- Create the build directory structure used by compile -->
- <mkdir dir="${build}"/>
- </target>
-
- <target name="compile" depends="init"
- description="compile the source " >
- <!-- Compile the java code from ${src} into ${build} -->
- <javac srcdir="${src}" destdir="${build}"/>
- </target>
-
- <target name="dist" depends="compile"
- description="generate the distribution" >
- <!-- Create the distribution directory -->
- <mkdir dir="${dist}/lib"/>
-
- <!-- Put everything in ${build} into the MyProject-${DSTAMP}.jar file -->
- <jar jarfile="${dist}/lib/MyProject-${DSTAMP}.jar" basedir="${build}"/>
- </target>
-
- <target name="clean"
- description="clean up" >
- <!-- Delete the ${build} and ${dist} directory trees -->
- <delete dir="${build}"/>
- <delete dir="${dist}"/>
- </target>
- </project>
- </pre>
-
- <p>Notice that we are declaring properties outside any target. As of
- Ant 1.6 all tasks can be declared outside targets (earlier version
- only allowed <tt><property></tt>,<tt><typedef></tt> and
- <tt><taskdef></tt>). When you do this they are evaluated before
- any targets are executed. Some tasks will generate build failures if
- they are used outside of targets as they may cause infinite loops
- otherwise (<code><antcall></code> for example).</p>
-
- <p>
- We have given some targets descriptions; this causes the <tt>projecthelp</tt>
- invocation option to list them as public targets with the descriptions; the
- other target is internal and not listed.
- <p>
- Finally, for this target to work the source in the <tt>src</tt> subdirectory
- should be stored in a directory tree which matches the package names. Check the
- <tt><javac></tt> task for details.
-
- <h3><a name="filters">Token Filters</a></h3>
- <p>A project can have a set of tokens that might be automatically expanded if
- found when a file is copied, when the filtering-copy behavior is selected in the
- tasks that support this. These might be set in the buildfile
- by the <a href="Tasks/filter.html">filter</a> task.</p>
- <p>Since this can potentially be a very harmful behavior,
- the tokens in the files <b>must</b>
- be of the form <code>@</code><i>token</i><code>@</code>, where
- <i>token</i> is the token name that is set
- in the <code><filter></code> task. This token syntax matches the syntax of other build systems
- that perform such filtering and remains sufficiently orthogonal to most
- programming and scripting languages, as well as with documentation systems.</p>
- <p>Note: If a token with the format <code>@</code><i>token</i><code>@</code>
- is found in a file, but no
- filter is associated with that token, no changes take place;
- therefore, no escaping
- method is available - but as long as you choose appropriate names for your
- tokens, this should not cause problems.</p>
- <p><b>Warning:</b> If you copy binary files with filtering turned on, you can corrupt the
- files. This feature should be used with text files <em>only</em>.</p>
-
- <h3><a name="path">Path-like Structures</a></h3>
- <p>You can specify <code>PATH</code>- and <code>CLASSPATH</code>-type
- references using both
- "<code>:</code>" and "<code>;</code>" as separator
- characters. Ant will
- convert the separator to the correct character of the current operating
- system.</p>
- <p>Wherever path-like values need to be specified, a nested element can
- be used. This takes the general form of:</p>
- <pre>
- <classpath>
- <pathelement path="${classpath}"/>
- <pathelement location="lib/helper.jar"/>
- </classpath>
- </pre>
- <p>The <code>location</code> attribute specifies a single file or
- directory relative to the project's base directory (or an absolute
- filename), while the <code>path</code> attribute accepts colon-
- or semicolon-separated lists of locations. The <code>path</code>
- attribute is intended to be used with predefined paths - in any other
- case, multiple elements with <code>location</code> attributes should be
- preferred.</p>
- <p><em>Since Ant 1.8.2</em> the location attribute can also contain a
- wildcard in its last path component (i.e. it can end in a
- "*") in order to support wildcard CLASSPATHs introduced
- with Java6. Ant will not expand or evaluate the wildcards and the
- resulting path may not work as anything else but a CLASSPATH - or
- even as a CLASSPATH for a Java VM prior to Java6.</p>
- <p>As a shortcut, the <code><classpath></code> tag
- supports <code>path</code> and
- <code>location</code> attributes of its own, so:</p>
- <pre>
- <classpath>
- <pathelement path="${classpath}"/>
- </classpath>
- </pre>
- <p>can be abbreviated to:</p>
- <pre>
- <classpath path="${classpath}"/>
- </pre>
- <p>In addition, one or more
- <a href="Types/resources.html#collection">Resource Collection</a>s
- can be specified as nested elements (these must consist of
- <a href="Types/resources.html#file">file</a>-type resources only).
- Additionally, it should be noted that although resource collections are
- processed in the order encountered, certain resource collection types
- such as <a href="Types/fileset.html">fileset</a>,
- <a href="Types/dirset.html">dirset</a> and
- <a href="Types/resources.html#files">files</a>
- are undefined in terms of order.</p>
- <pre>
- <classpath>
- <pathelement path="${classpath}"/>
- <fileset dir="lib">
- <include name="**/*.jar"/>
- </fileset>
- <pathelement location="classes"/>
- <dirset dir="${build.dir}">
- <include name="apps/**/classes"/>
- <exclude name="apps/**/*Test*"/>
- </dirset>
- <filelist refid="third-party_jars"/>
- </classpath>
- </pre>
- <p>This builds a path that holds the value of <code>${classpath}</code>,
- followed by all jar files in the <code>lib</code> directory,
- the <code>classes</code> directory, all directories named
- <code>classes</code> under the <code>apps</code> subdirectory of
- <code>${build.dir}</code>, except those
- that have the text <code>Test</code> in their name, and
- the files specified in the referenced FileList.</p>
- <p>If you want to use the same path-like structure for several tasks,
- you can define them with a <code><path></code> element at the
- same level as <i>target</i>s, and reference them via their
- <i>id</i> attribute--see <a href="#references">References</a> for an
- example.</p>
-
- <p>By default a path like structure will re-evaluate all nested
- resource collections whenever it is used, which may lead to
- unnecessary re-scanning of the filesystem. Since Ant 1.8.0 path has
- an optional <i>cache</i> attribute, if it is set to true, the path
- instance will only scan its nested resource collections once and
- assume it doesn't change during the build anymore (the default
- for <i>cache</i> still is <i>false</i>). Even if you are using the
- path only in a single task it may improve overall performance to set
- <i>cache</i> to <i>true</i> if you are using complex nested
- constructs.</p>
-
- <p>A path-like structure can include a reference to another path-like
- structure (a path being itself a resource collection)
- via nested <code><path></code> elements:</p>
- <pre>
- <path id="base.path">
- <pathelement path="${classpath}"/>
- <fileset dir="lib">
- <include name="**/*.jar"/>
- </fileset>
- <pathelement location="classes"/>
- </path>
-
- <path id="tests.path" cache="true">
- <path refid="base.path"/>
- <pathelement location="testclasses"/>
- </path>
- </pre>
- The shortcuts previously mentioned for <code><classpath></code> are also valid for <code><path></code>.For example:
- <pre>
- <path id="base.path">
- <pathelement path="${classpath}"/>
- </path>
- </pre>
- can be written as:
- <pre>
- <path id="base.path" path="${classpath}"/>
- </pre>
-
- <h4><a name="pathshortcut">Path Shortcut</a></h4>
- <p>
- In Ant 1.6 a shortcut for converting paths to OS specific strings
- in properties has been added. One can use the expression
- ${toString:<em>pathreference</em>} to convert a path element
- reference to a string that can be used for a path argument.
- For example:
- </p>
- <pre>
- <path id="lib.path.ref">
- <fileset dir="lib" includes="*.jar"/>
- </path>
- <javac srcdir="src" destdir="classes">
- <compilerarg arg="-Xbootclasspath/p:${toString:lib.path.ref}"/>
- </javac>
- </pre>
-
-
- <h3><a name="arg">Command-line Arguments</a></h3>
- <p>Several tasks take arguments that will be passed to another
- process on the command line. To make it easier to specify arguments
- that contain space characters, nested <code>arg</code> elements can be used.</p>
- <table border="1" cellpadding="2" cellspacing="0">
- <tr>
- <td width="12%" valign="top"><b>Attribute</b></td>
- <td width="78%" valign="top"><b>Description</b></td>
- <td width="10%" valign="top"><b>Required</b></td>
- </tr>
- <tr>
- <td valign="top">value</td>
- <td valign="top">a single command-line argument; can contain space
- characters.</td>
- <td align="center" rowspan="5">Exactly one of these.</td>
- </tr>
- <tr>
- <td valign="top">file</td>
- <td valign="top">The name of a file as a single command-line
- argument; will be replaced with the absolute filename of the file.</td>
- </tr>
- <tr>
- <td valign="top">path</td>
- <td valign="top">A string that will be treated as a path-like
- string as a single command-line argument; you can use <code>;</code>
- or <code>:</code> as
- path separators and Ant will convert it to the platform's local
- conventions.</td>
- </tr>
- <tr>
- <td valign="top">pathref</td>
- <td valign="top"><a href="#references">Reference</a> to a path
- defined elsewhere. Ant will convert it to the platform's local
- conventions.</td>
- </tr>
- <tr>
- <td valign="top">line</td>
- <td valign="top">a space-delimited list of command-line arguments.</td>
- </tr>
- <tr>
- <td valign="top">prefix</td>
- <td valign="top">A fixed string to be placed in front of the
- argument. In the case of a line broken into parts, it will be
- placed in front of every part. <em>Since Ant 1.8.</em></td>
- <td valign="top" align="center">No</td>
- </tr>
- <tr>
- <td valign="top">suffix</td>
- <td valign="top">A fixed string to be placed immediately after the
- argument. In the case of a line broken into parts, it will be
- placed after every part. <em>Since Ant 1.8.</em></td>
- <td valign="top" align="center">No</td>
- </tr>
- </table>
-
- <p>It is highly recommended to avoid the <code>line</code> version
- when possible. Ant will try to split the command line in a way
- similar to what a (Unix) shell would do, but may create something that
- is very different from what you expect under some circumstances.</p>
-
- <h4>Examples</h4>
- <blockquote><pre>
- <arg value="-l -a"/>
- </pre></blockquote>
- <p>is a single command-line argument containing a space character,
- <i>not</i> separate commands "-l" and "-a".</p>
- <blockquote><pre>
- <arg line="-l -a"/>
- </pre></blockquote>
- <p>This is a command line with two separate arguments, "-l" and "-a".</p>
- <blockquote><pre>
- <arg path="/dir;/dir2:\dir3"/>
- </pre></blockquote>
- <p>is a single command-line argument with the value
- <code>\dir;\dir2;\dir3</code> on DOS-based systems and
- <code>/dir:/dir2:/dir3</code> on Unix-like systems.</p>
-
- <h3><a name="references">References</a></h3>
-
- <p>Any project element can be assigned an identifier using its
- <code>id</code> attribute. In most cases the element can subsequently
- be referenced by specifying the <code>refid</code> attribute on an
- element of the same type. This can be useful if you are going to
- replicate the same snippet of XML over and over again--using a
- <code><classpath></code> structure more than once, for example.</p>
- <p>The following example:</p>
- <blockquote><pre>
- <project ... >
- <target ... >
- <rmic ...>
- <classpath>
- <pathelement location="lib/"/>
- <pathelement path="${java.class.path}/"/>
- <pathelement path="${additional.path}"/>
- </classpath>
- </rmic>
- </target>
-
- <target ... >
- <javac ...>
- <classpath>
- <pathelement location="lib/"/>
- <pathelement path="${java.class.path}/"/>
- <pathelement path="${additional.path}"/>
- </classpath>
- </javac>
- </target>
- </project>
- </pre></blockquote>
- <p>could be rewritten as:</p>
- <blockquote><pre>
- <project ... >
- <path id="project.class.path">
- <pathelement location="lib/"/>
- <pathelement path="${java.class.path}/"/>
- <pathelement path="${additional.path}"/>
- </path>
-
- <target ... >
- <rmic ...>
- <classpath refid="project.class.path"/>
- </rmic>
- </target>
-
- <target ... >
- <javac ...>
- <classpath refid="project.class.path"/>
- </javac>
- </target>
- </project>
- </pre></blockquote>
- <p>All tasks that use nested elements for
- <a href="Types/patternset.html">PatternSet</a>s,
- <a href="Types/fileset.html">FileSet</a>s,
- <a href="Types/zipfileset.html">ZipFileSet</a>s or
- <a href="#path">path-like structures</a> accept references to these structures
- as shown in the examples. Using <code>refid</code> on a task will ordinarily
- have the same effect (referencing a task already declared), but the user
- should be aware that the interpretation of this attribute is dependent on the
- implementation of the element upon which it is specified. Some tasks (the
- <a href="Tasks/property.html">property</a> task is a handy example)
- deliberately assign a different meaning to <code>refid</code>.</p>
-
-
- <h3><a name="external-tasks">Use of external tasks</a></h3>
- Ant supports a plugin mechanism for using third party tasks. For using them you
- have to do two steps:
- <ol>
- <li>place their implementation somewhere where Ant can find them</li>
- <li>declare them.</li>
- </ol>
- Don't add anything to the CLASSPATH environment variable - this is often the
- reason for very obscure errors. Use Ant's own <a href="install.html#optionalTasks">mechanisms</a>
- for adding libraries:
- <ul>
- <li>via command line argument <code>-lib</code></li>
- <li>adding to <code>${user.home}/.ant/lib</code></li>
- <li>adding to <code>${ant.home}/lib</code></li>
- </ul>
- For the declaration there are several ways:
- <ul>
- <li>declare a single task per using instruction using
- <code><<a href="Tasks/taskdef.html">taskdef</a> name="taskname"
- classname="ImplementationClass"/></code>
- <br>
- <code><taskdef name="for" classname="net.sf.antcontrib.logic.For" />
- <for ... /></code>
- </li>
- <li>declare a bundle of tasks using a properties-file holding these
- taskname-ImplementationClass-pairs and <code><taskdef></code>
- <br>
- <code><taskdef resource="net/sf/antcontrib/antcontrib.properties" />
- <for ... /></code>
- </li>
- <li>declare a bundle of tasks using a <a href="Types/antlib.html">xml-file</a> holding these
- taskname-ImplementationClass-pairs and <code><taskdef></code>
- <br>
- <code><taskdef resource="net/sf/antcontrib/antlib.xml" />
- <for ... /></code>
- </li>
- <li>declare a bundle of tasks using a xml-file named antlib.xml, XML-namespace and
- <a href="Types/antlib.html#antlibnamespace"><code>antlib:</code> protocol handler</a>
- <br>
- <code><project xmlns:ac="antlib:net.sf.antcontrib"/>
- <ac:for ... /></code>
- </li>
- </ul>
-
- If you need a special function, you should
- <ol>
- <li>have a look at this manual, because Ant provides lot of tasks</li>
- <li>have a look at the external task page in the <a href="../external.html">manual</a>
- (or better <a href="http://ant.apache.org/external.html">online</a>)</li>
- <li>have a look at the external task <a href="http://wiki.apache.org/ant/AntExternalTaskdefs">wiki
- page</a></li>
- <li>ask on the <a href="http://ant.apache.org/mail.html#User%20List">Ant user</a> list</li>
- <li><a href="tutorial-writing-tasks.html">implement </a>(and share) your own</li>
- </ol>
-
- </body>
- </html>
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