异常体系结构

偏执的太偏执、 2022-09-05 05:30 172阅读 0赞

## 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));
    		
    	}
    	
    	
    }