Android Java 自定义异常

package com; public class ZeroException extends Exception { private static final long serialVersionUID = 1L; public ZeroException(){ super() ; } public ZeroException ( String string ) { super( string ) ; } }

package com; public class Test { public static void main(String[] args) { Test test = new Test() ; try { test.fun( "" ) ; } catch (ZeroException e) { e.printStackTrace(); } } void fun( String string ) throws ZeroException { if( string == null ){ throw new ZeroException( "参数不能为null" ) ; } if( string == "" ) { throw new ZeroException( "参数不能为空" ) ; } } }

com.ZeroException: 参数不能为空 at com.Test.fun(Test.java:22) at com.Test.main(Test.java:9)