There are a number of opportunities to use the new try-with-resources feature of Java 7 in the pack200 library code. The affected files are as follows:

src/share/classes/com/sun/java/util/jar/pack/BandStructure.java
src/share/classes/com/sun/java/util/jar/pack/Driver.java
src/share/classes/com/sun/java/util/jar/pack/NativeUnpack.java
src/share/classes/com/sun/java/util/jar/pack/PackageReader.java
src/share/classes/com/sun/java/util/jar/pack/PackageWriter.java
src/share/classes/com/sun/java/util/jar/pack/PropMap.java
src/share/classes/com/sun/java/util/jar/pack/UnpackerImpl.java
src/share/classes/com/sun/java/util/jar/pack/Utils.java