JVM 看不到某些异常的stacktrace问题(转)

The compiler in the server VM now provides correct stack backtraces for all "cold" built-in exceptions. 
For performance purposes, when such an exception is thrown a few times, the method may be recompiled. 
After recompilation, the compiler may choose a faster tactic using preallocated exceptions that do not provide a stack trace. 
To disable completely the use of preallocated exceptions, 
use this new flag: -XX:-OmitStackTraceInFastThrow.

public class TestCompile {
        private static final int count = 1000000;
        /**
         * @param args
         */
        public static void main(String[] args)throws Exception {
                int index = count;
                while(index -- > 0){
                        try {
                                work();
                        } catch (Exception e) {
                                e.printStackTrace();
                        }
                }
        }
        private static void work(){
                        String value = null;
                        value.length();
        }
}

java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException