I recommend using Apache Ant and YUI Compressor.
http://ant.apache.org/
http://yui.github.com/yuicompressor/
Put something like this in the Ant build xml.
It will create two files, application.js and application-min.js.
<target name="concatenate" description="Concatenate all js files">
<concat destfile="build/application.js">
<fileset dir="src/js" includes="*.js" />
</concat>
</target>
<target name="compress" depends="concatenate" description="Compress application.js to application-min.js">
<apply executable="java" parallel="false">
<filelist dir="build" files="application.js" />
<arg line="-jar" />
<arg path="path/to/yuicompressor-2.4.2.jar" />
<srcfile />
<arg line="-o" />
<mapper type="glob" from="*.js" to="build/*-min.js" />
<targetfile />
</apply>
</target>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…