标签：style blog io ar color sp java on div
Exception in thread "main" java.lang.NullPointerException
at com.gs.test.AppTest.main(AppTest.java:34)
public static void main(String[] args) { Map<String, Integer> map=new HashMap<String, Integer>(); map.put("b",1); int i=map.get("a"); System.err.println(i); }
标签：style blog io ar color sp java on div
原文地址：http://www.cnblogs.com/muzhongjiang/p/4123775.html
