异常体系结构-蒲公英云

异常体系结构

常见异常

异常体系结构

package com.atguigu.java1;
import java.io.File;
import java.io.FileInputStream;
import java.util.Date;
import java.util.Scanner;
import org.junit.Test;
public class ExceptionTest { 
    //******************以下是编译时异常***************************
    @Test
    public void test7(){ 
// File file = new File("hello.txt");
// FileInputStream fis = new FileInputStream(file);
// 
// int data = fis.read();
// while(data != -1){ 
// System.out.print((char)data);
// data = fis.read();
// }
// 
// fis.close();
    }
    //******************以下是运行时异常***************************
    //ArithmeticException
    @Test
    public void test6(){ 
        int a = 10;
        int b = 0;
        System.out.println(a / b);
    }
    //InputMismatchException
    @Test
    public void test5(){ 
        Scanner scanner = new Scanner(System.in);
        int score = scanner.nextInt();
        System.out.println(score);
        scanner.close();
    }
    //NumberFormatException
    @Test
    public void test4(){ 
        String str = "123";
        str = "abc";
        int num = Integer.parseInt(str);
    }
    //ClassCastException
    @Test
    public void test3(){ 
        Object obj = new Date();
        String str = (String)obj;
    }
    //IndexOutOfBoundsException
    @Test
    public void test2(){ 
        //ArrayIndexOutOfBoundsException
// int[] arr = new int[10];
// System.out.println(arr[10]);
        //StringIndexOutOfBoundsException
        String str = "abc";
        System.out.println(str.charAt(3));
    }
    //NullPointerException
    @Test
    public void test1(){ 
// int[] arr = null;
// System.out.println(arr[3]);
        String str = "abc";
        str = null;
        System.out.println(str.charAt(0));
    }
}