title: adding jar library files to an ant build
body: <p>I added <code>commons-codec.1.2.jar</code> to my Java Build Path</p>
  
  <pre><code>    [javac] C:\Users\souzamor\workspace\tczip\src\tczip\Tczip.java:190: error: c
  annot find symbol
      [javac]   mdEnc = new String( Hex.encodeHex( diges
  t ));
      [javac]                       ^
  </code></pre>
  
  <p>and here is my <code>build.xml</code> file:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project&gt;
  
      &lt;target name="clean"&gt;
          &lt;delete dir="build" /&gt;
      &lt;/target&gt;
  
      &lt;target name="compile"&gt;
          &lt;mkdir dir="build/classes" /&gt;
          &lt;javac srcdir="src" destdir="build/classes" /&gt;
      &lt;/target&gt;
  
      &lt;target name="jar"&gt;
          &lt;mkdir dir="build/jar" /&gt;
          &lt;jar destfile="build/jar/Tczip.jar" basedir="build/classes"&gt;
              &lt;manifest&gt;
                  &lt;attribute name="Main-Class" value="tczip.ZipComparison" /&gt;
              &lt;/manifest&gt;
          &lt;/jar&gt;
      &lt;/target&gt;
  
      &lt;target name="run"&gt;
          &lt;java jar="build/jar/Tczip.jar" fork="true" /&gt;
      &lt;/target&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>How could I add the jar files into the <code>build.xml</code> file?? I also have another <code>Java</code> class called <code>Tczip</code> which processes <code>MD5</code>:</p>
  
  <pre><code> [java] Processing: bhmcommonclient.zip
   [java] Exception in thread "main" java.lang.NoClassDefFoundError: org/apach
  mmons/codec/binary/Hex
   [java]     at tczip.Tczip.digest(Unknown Source)
   [java]     at tczip.Tczip.execute(Unknown Source)
   [java]     at tczip.ZipComparison.showFiles(Unknown Source)
   [java]     at tczip.ZipComparison.showFiles(Unknown Source)
   [java]     at tczip.ZipComparison.showFiles(Unknown Source)
   [java]     at tczip.ZipComparison.showFiles(Unknown Source)
   [java]     at tczip.ZipComparison.showFiles(Unknown Source)
   [java]     at tczip.ZipComparison.matchMD5(Unknown Source)
   [java]     at tczip.ZipComparison.main(Unknown Source)
  </code></pre>
  
  <p>I don't think I'm adding that correctly to my jar file ... how could I do that? I'm totally new to <code>Ant</code></p>