1.异常的概念
什么是异常？程序出错分为两部分，编译时出粗和运行时出错。编译时出错是编译器在编译源码时发生的错误；
运行时出错是在编译通过，在运行时出现的错误。这种情况叫异常。
例如：数组越界，除数为0，文件找不到等等。
异常的层次：
Object
Throwable
Error
Exception
RuntimeException
IOException
2.如何解决异常
a.使用try...catch
public class UsingTryCatch { public static void main(String args[]) { int a = 5; int b = 0; int result = 0; try { result = a / b; } catch (Exception e) { System.out.println(e); } } }
b.使用throws或throw关键字
public class UsingThrows { public static void main(String args[]) { try { Caculation caculation = new Caculation(); } catch (Exception e) { e.printStackTrace(); } } public static class Caculation{ int a = 5; int b = 0; int result = 0; public Caculation()throws Exception{ result = a/b; System.out.println(result); } } }
public class UsingThrow {public static void main(String args[]) { try { // Caculation caculation = new Caculation(); throw new Exception("实例化Exception"); } catch (Exception e) { e.printStackTrace(); } } public static class Caculation{ int a = 5; int b = 0; int result = 0; public Caculation()throws Exception{ result = a/b; System.out.println(result); } } }
原文：http://www.cnblogs.com/prescheng/p/5838975.html