java.util.zip package provides classes for reading and writing the standard ZIP and GZIP file formats. Also includes classes for compressing and decompressing data using the DEFLATE compression algorithm, which is used by the ZIP and GZIP file formats. Additionally, there are utipty classes for computing the CRC-32 and Adler-32 checksums of arbitrary input streams.

This reference will take you through simple and practical methods available in java.util.zip package.