Here you can find the source of getCRC()
public static CRC32 getCRC()
//package com.java2s; import java.util.zip.CRC32; public class Main { private static final ThreadLocal<CRC32> crcProvider = new ThreadLocal<CRC32>() { protected CRC32 initialValue() { return new CRC32(); }//from w ww .j a va 2s.c o m }; /** thread-singleton crc engine */ public static CRC32 getCRC() { return crcProvider.get(); } }