动手动脑
【1】
import javax.swing.*;
class AboutException {
public static void main(String[] a)
{
int i=1, j=0, k;
k=i/j;
try
{
k = i/j; // Causes division-by-zero exception
//throw new Exception("Hello.Exception!");
}
catch ( ArithmeticException e)
{
System.out.println("被0除. "+ e.getMessage());
}
catch (Exception e)
{
if (e instanceof ArithmeticException)
System.out.println("被0除");
else
{
System.out.println(e.getMessage());
}
}
finally
{
JOptionPane.showConfirmDialog(null,"OK");
}
}
}
【运行截图】
【2】
public class CatchWho {
public static void main(String[] args) {
try {
try {
throw new ArrayIndexOutOfBoundsException();
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch");
}
throw new ArithmeticException();
}
catch(ArithmeticException e) {
System.out.println("发生ArithmeticException");
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch");
}
}
}
运行截图:
【3】
public class CatchWho2 {
public static void main(String[] args) {
try {
try {
throw new ArrayIndexOutOfBoundsException();
}
catch(ArithmeticException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch");
}
throw new ArithmeticException();
}
catch(ArithmeticException e) {
System.out.println("发生ArithmeticException");
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch");
}
}
}
运行截图:
【4】
public class EmbedFinally {
public static void main(String args[]) {
int result;
try {
System.out.println("in Level 1");
try {
System.out.println("in Level 2");
// result=100/0; //Level 2
try {
System.out.println("in Level 3");
result=100/0; //Level 3
}
catch (Exception e) {
System.out.println("Level 3:" + e.getClass().toString());
}
finally {
System.out.println("In Level 3 finally");
}
// result=100/0; //Level 2
}
catch (Exception e) {
System.out.println("Level 2:" + e.getClass().toString());
}
finally {
System.out.println("In Level 2 finally");
}
// result = 100 / 0; //level 1
}
catch (Exception e) {
System.out.println("Level 1:" + e.getClass().toString());
}
finally {
System.out.println("In Level 1 finally");
}
}
}
【运行截图】
【5】
public class SystemExitAndFinally {
public static void main(String[] args)
{
try{
System.out.println("in main");
throw new Exception("Exception is thrown in main");
//System.exit(0);
}
catch(Exception e)
{
System.out.println(e.getMessage());
System.exit(0);
}
finally
{
System.out.println("in finally");
}
}
}
运行截图:
分析:
按理说finally是一定执行的,但也不排除特例,
它的运行结果只有
in main
Exception is thrown in main
我们发现他的finally没有执行
这是因为 System.exit(status);这个方法是用来结束当前正在运行中的java虚拟机。如何status是非零参数,那么表示是非正常退出。
import java.util.Scanner;
public class Test7 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner con=new Scanner(System.in);
try {
System.out.println("请输入成绩:");
int ch=con.nextInt();
if(ch<60&&ch>=0) {System.out.println("不及格!");}
else if(ch==60) {System.out.println("及格!");}
else if(ch>60&&ch<80) {System.out.println("中!");}
else if(ch>=80&&ch<90) {System.out.println("良!");}
else if(ch>=90&&ch<=100){System.out.println("优!");}
}catch(ArrayStoreException e){
e.printStackTrace();
}finally {
System.out.println("Over");
System.exit(0);
}
}
}
【运行截图】