异常综合练习

package com.tedu.exception;
/**
 * 异常综合练习
 * 
 * @author Wildmess
 *
 *不管怎样都会执行的语句
 *finally(关键字,常量)，fianlly(异常中的块),finalize(Object类中的方法)
 */
public class FinallyDemo4 {
	public static void main(String[] args) {
		System.out.println(test(null));
		System.out.println(test(""));
		System.out.println(test("a"));//97
		System.out.println(test(null) + "," + test("") + "," +test("a"));
	}
	public static int test(String str) {
		try {
			System.out.println("调用了test:" + str);
			return str.charAt(0);
		} catch (NullPointerException e) {
			System.out.println("出现了空指针！");
			return 1;
		} catch(StringIndexOutOfBoundsException e) {
			System.out.println("出现了字符越界！");
			return 2;
		} catch (Exception e) {
			System.out.println("未知错误！");
			return 3;
		} finally {
			System.out.println("执行了finally");
		}
	}
}