java空指针出现的情况：拆箱装箱

让普通变量 long = 一个空的Long对象

public class UnboxingNpe {private static int add(int x, int y) {return x + y;}private static boolean compare(long x, long y) {return x >= y;}public static void main(String[] args) {// 1. 变量赋值自动拆箱出现的空指针// javac UnboxingNpe.java// javap -c UnboxingNpe.classLong count = null;long count_ = count;// 2. 方法传参时自动拆箱引发的空指针
//        Integer left = null;
//        Integer right = null;
//        System.out.println(add(left, right));// 3. 用于大小比较的场景
//        Long left = 10L;
//        Long right = null;
//        System.out.println(compare(left, right));}
}