java学习（23）_运行时异常总结

java学习（23）_运行时异常总结（待完善。。）

运行时异常：运行时异常都是RuntimeException的子类

1. NullPointerException    空指针异常

示例：

public class Test01 {public static void main(String[] args) {String s= null;System.out.println(s.charAt(0));}}

2. ArithmeticException  数学异常

示例：

public class Test01 {public static void main(String[] args) {System.out.println(1/0);}}

3.ClassCastException  类型转换异常

示例：

class A{}class B extends A{}public class Test01 {public static void main(String[] args) {A a = new A();B b = (B) a;}}

4.ArrayIndexOutOfBoundsException 数组下标越界异常

示例：

public class Test01 {public static void main(String[] args) {int[] a = new int[2];System.out.println(a[4]);}}

5.StringIndexOutOfBoundsException 字符串下标越界

示例：

public class Test01 {public static void main(String[] args) {String s = "abc";System.out.println(s.charAt(5));}}

6.IndexOutOfBoundsException  下标越界异常

示例：

public class Test01 {public static void main(String[] args) {ArrayList<Integer> list = new ArrayList<Integer>();list.add(1);System.out.println(list.get(3));}}

7.NumberFormatException 数字格式化异常

示例：

public class Test01 {public static void main(String[] args) {System.out.println(Integer.parseInt("1a2"));}}

8.InputMismatchException  输入不匹配异常

public class Test01 {public static void main(String[] args) {Scanner sc = new Scanner(System.in);System.out.println("请输入一个整数：");int a = sc.nextInt();}}

9.ArrayStoreException  数组协变异常

示例：

public class Test01 {public static void main(String[] args) {String[] s = new String[3];Object[] o =s;o[1] = 1;}}

10.ConcurrentModificationException   快速报错异常

示例：

public class Test01 {public static void main(String[] args) {List list = new ArrayList(Arrays.asList(1,2,3));Iterator it = list.iterator();while(it.hasNext()){System.out.println(it.next());list.add(4);}}}

11.UnsupportedOperationException  不支持该操作异常

public class Test01 {public static void main(String[] args) {List list = Arrays.asList(1,2,3);list.add(4);}}

12.NoSuchElementException    没有这么一个元素异常

示例：

public class Test01 {public static void main(String[] args) {List list = Arrays.asList(1,2,3);Iterator it = list.iterator();System.out.println(it.next());System.out.println(it.next());System.out.println(it.next());System.out.println(it.next());}}

13.IllegealMonitorStateException  非法监听器状态

示例：

class A implements Runnable{Object obj;public A(Object obj){this.obj = obj;}@Overridepublic void run() {while(true){synchronized (obj) {System.out.println("1234");try {obj.notify();obj.wait();} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}}class B implements Runnable{Object obj;public B(Object obj){this.obj = obj;}@Overridepublic void run() {while(true){synchronized (obj) {System.out.println("abcd");}try {obj.notify();obj.wait();} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}public class Test01 {public static void main(String[] args) {Object obj = new Object();Thread t1 = new Thread(new A(obj));Thread t2 = new Thread(new B(obj));t1.start();t2.start();}}

14.EmptyStackException 空栈异常

public class Test01 {public static void main(String[] args) {Stack s = new Stack();s.push(1);s.pop();s.pop();}}