怎么使用ant 创建Manifest.mf的classpath

 

UPDATE It seems this is at least partly outdated, have a look at manifestclasspath .

It is possible to define .jar dependencies in the MANIFEST.MF of the main .jar file, it is just a comma seperated string which looks like this:

Class-Path: lib/log4j.jar lib/commons.jar

In a project I work on, we keep all our dependencies in a lib directory, where we add and remove libraries from time to time, therefore it would be nice if the above text can be generated automatically. Fortunately, this is possible using just Ant . Unfortunately, this is rather cumbersome. (If you want something more powerful and simpler to use, have a look at Rake ).

In a nutshell, this is how I did it:

 

1. First, let’s define some properties:

   <!-- name of the output .jar file -->
   <
   property
    
   name
   =
   "jar.name"
    
   value
   =
   "ourjarfile.jar"
    
   />
   
   <!-- base directory for distribution target -->
   <
   property
    
   name
   =
   "dist.home"
    
   value
   =
   "dist"
    
   />
   
   <!-- base directory for compilation targets -->
   <
   property
    
   name
   =
   "build.home"
    
   value
   =
   "target"
    
   />
   
   <!-- The base directory for all libraries (jar) files -->
   <
   property
    
   name
   =
   "lib.home"
    
   value
   =
   "lib"
    
   />

   <!-- name of the output .jar file -->
   <property name="jar.name" value="ourjarfile.jar" />
   
   <!-- base directory for distribution target -->
   <property name="dist.home" value="dist" />
   
   <!-- base directory for compilation targets -->
   <property name="build.home" value="target" />
   
   <!-- The base directory for all libraries (jar) files -->
   <property name="lib.home" value="lib" />
   

2. Now to the fun part, create a nice .jar file. This generates the MANIFEST.MF but first generates a property libs.project that contains all .jar files, sperated with space. If you later look at the generated MANIFEST.MF you will notice that the paths are wrapped every 72 character, even in the middle of the word. Although this looks like an error, it works correctly.

   <
   target
    
   name
   =
   "jar"
    
   depends
   =
   "compile"
    
   description
   =
   "Create jar and MANIFEST.MF"
   >
   
     <!-- create a property containing all .jar files, prefix lib/, and seperated with a space -->
     <
   pathconvert
    
   property
   =
   "libs.project"
    
   pathsep
   =
   " "
   >
       <
   mapper
   >
         <
   chainedmapper
   >
   
           <!-- remove absolute path -->
           <
   flattenmapper
    
   />
   
           <!-- add lib/ prefix -->
           <
   globmapper
    
   from
   =
   "*"
    
   to
   =
   "lib/*"
    
   />
         </
   chainedmapper
   >
       </
   mapper
   >
   
       <
   path
   >
   
         <!-- lib.home contains all jar files, in several subdirectories -->
         <
   fileset
    
   dir
   =
   "${lib.home}"
   >
           <
   include
    
   name
   =
   "**/*.jar"
    
   />
         </
   fileset
   >
       </
   path
   >
     </
   pathconvert
   >
   
     <!-- create the jar -->
     <
   jar
    
   jarfile
   =
   "${build.home}/${jar.name}"
    
   basedir
   =
   "${build.home}/classes"
   >
   
       <!-- define MANIFEST.MF -->
       <
   manifest
   >
         <
   attribute
    
   name
   =
   "Built-By"
    
   value
   =
   "${user.name}"
    
   />
         <
   attribute
    
   name
   =
   "Main-Class"
    
   value
   =
   "my.path.to.the.main.Application"
    
   />
         <
   section
    
   name
   =
   "common"
   >
           <
   attribute
    
   name
   =
   "Specification-Title"
    
   value
   =
   "${component.name}"
    
   />
           <
   attribute
    
   name
   =
   "Specification-Version"
    
   value
   =
   "${component.version}"
    
   />
           <
   attribute
    
   name
   =
   "Specification-Vendor"
    
   value
   =
   "${component.vendor}"
    
   />
           <
   attribute
    
   name
   =
   "Implementation-Title"
    
   value
   =
   "${component.name}"
    
   />
           <
   attribute
    
   name
   =
   "Implementation-Version"
    
   value
   =
   "${component.version} ${TODAY}"
    
   />
           <
   attribute
    
   name
   =
   "Implementation-Vendor"
    
   value
   =
   "${component.vendor}"
    
   />
         </
   section
   >
   
         <!-- finally, use the magically generated libs path -->
         <
   attribute
    
   name
   =
   "Class-Path"
    
   value
   =
   "${libs.project}"
    
   />
       </
   manifest
   >
     </
   jar
   >
   </
   target
   >

   <target name="jar" depends="compile" description="Create jar and MANIFEST.MF">
   
     <!-- create a property containing all .jar files, prefix lib/, and seperated with a space -->
     <pathconvert property="libs.project" pathsep=" ">
       <mapper>
         <chainedmapper>
   
           <!-- remove absolute path -->
           <flattenmapper />
   
           <!-- add lib/ prefix -->
           <globmapper from="*" to="lib/*" />
         </chainedmapper>
       </mapper>
   
       <path>
   
         <!-- lib.home contains all jar files, in several subdirectories -->
         <fileset dir="${lib.home}">
           <include name="**/*.jar" />
         </fileset>
       </path>
     </pathconvert>
   
     <!-- create the jar -->
     <jar jarfile="${build.home}/${jar.name}" basedir="${build.home}/classes">
   
       <!-- define MANIFEST.MF -->
       <manifest>
         <attribute name="Built-By" value="${user.name}" />
         <attribute name="Main-Class" value="my.path.to.the.main.Application" />
         <section name="common">
           <attribute name="Specification-Title" value="${component.name}" />
           <attribute name="Specification-Version" value="${component.version}" />
           <attribute name="Specification-Vendor" value="${component.vendor}" />
           <attribute name="Implementation-Title" value="${component.name}" />
           <attribute name="Implementation-Version" value="${component.version} ${TODAY}" />
           <attribute name="Implementation-Vendor" value="${component.vendor}" />
         </section>
   
         <!-- finally, use the magically generated libs path -->
         <attribute name="Class-Path" value="${libs.project}" />
       </manifest>
     </jar>
   </target>
   

3. Finally we need to create a distribution by copying all .jar files into dist/lib while using a flat directory structure:

   <
   target
    
   name
   =
   "dist"
    
   depends
   =
   "jar"
    
   description
   =
   "Create binary distribution"
   >
     <
   delete
    
   dir
   =
   "${dist.home}"
    
   />
   
     <!-- contains all library dependencies -->
     <
   mkdir
    
   dir
   =
   "${dist.home}/lib"
    
   />
   
     <
   copy
    
   todir
   =
   "${dist.home}"
    
   file
   =
   "${build.home}/${jar.name}"
    
   />
   
     <
   copy
    
   todir
   =
   "${dist.home}/lib"
    
   filtering
   =
   "off"
   >
   
       <!-- remove the directory hierarchy: lib contains no subdirectories -->
       <
   flattenmapper
    
   />
       <
   fileset
    
   dir
   =
   "${lib.home}"
    
   includes
   =
   "**/*.jar"
    
   />
     </
   copy
   >
   </
   target
   >

   <target name="dist" depends="jar" description="Create binary distribution">
     <delete dir="${dist.home}" />
   
     <!-- contains all library dependencies -->
     <mkdir dir="${dist.home}/lib" />
   
     <copy todir="${dist.home}" file="${build.home}/${jar.name}" />
   
     <copy todir="${dist.home}/lib" filtering="off">
   
       <!-- remove the directory hierarchy: lib contains no subdirectories -->
       <flattenmapper />
       <fileset dir="${lib.home}" includes="**/*.jar" />
     </copy>
   </target>
   

I use Ant 1.6.2, and this works perfectly for me. Have fun!