FULL PRODUCT VERSION :
java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
windows 8
windows xp
CentOS release 6.6 (Final)


A DESCRIPTION OF THE PROBLEM :
Byte.valueOf() cause bitwise operators got wrong result

REGRESSION.  Last worked in version 8u11

ADDITIONAL REGRESSION INFORMATION: 
java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
with -server option to run the code


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class Test {
	public static void main(String[] args) throws Exception {
		for (int i = 0, k = 20; i < Integer.MAX_VALUE; i++) {
			final Byte b = (byte) -1; // new Byte((byte) -1) won't work
			final int x = b.byteValue() & 0xff;
			if (i % 100 == 0) Thread.sleep(1); // or other operations to make this code run slower
			if (x == -1) System.out.println(x + " is -1 (" + i + ")"); // never happened
			if (x != 255) {
				System.out.println(x + " is not 255 (" + i + ")");
				if (x == -1) System.out.println(x + " is not 255 but -1 (" + i + ")"); // only once
				if (--k == 0) break; // change k value if you want more samples
			}
		}
	}
}
---------- END SOURCE ----------