Java异常断言

谁践踏了优雅 2023-01-07 07:26 169阅读 0赞

package com.msc.high;
    
    public class ExceptionDemo { 
        public static void main(String[] args) { 
            System.out.println("--------------begin1----------------");
            try { 
                System.out.println("10/0 = " + 10/0);
            }catch (ArithmeticException e){ 
                System.out.println(e);
                e.printStackTrace();
            }catch (Exception e){ 
                e.printStackTrace();
            } finally{ 
                System.out.println("执行finally");
            }
            System.out.println("--------------end1----------------");
            System.out.println("--------------begin2----------------");
            try { 
                System.out.println("10/0 = " + 10+2);
            }catch (ArithmeticException e){ 
                System.out.println(e);
                e.printStackTrace();
            }finally { 
                System.out.println("执行finally");
            }
            System.out.println("--------------end2----------------");
    
        }
    }

**输出**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]  
throw 抛出异常

package com.msc.high;
    class MyMath{ 
        public static int div(int x,int y) throws Exception{ 
            return x/y ;
        }
    }
    public class ExceptionDemo { 
        public static void main(String[] args)  {  //throws Exception
            try { 
                MyMath.div(10,0) ;
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }
    }

![在这里插入图片描述][20210116112940588.png]

package com.msc.high;
    class MyMath{ 
        public static int div(int x,int y) throws Exception{ 
            int temp = 0 ;
            System.out.println("------start--------");
    
            try{ 
                temp = x / y ;
            }catch (Exception e){ 
                throw e ;   //没有这一句 主方法输出为0 没有异常
            }finally { 
                System.out.println("----end--------");
            }
           return temp ;
        }
    }
    public class ExceptionDemo { 
        public static void main(String[] args)  { 
            try { 
                System.out.println(MyMath.div(10,0));
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }
    }

![在这里插入图片描述][20210116113814494.png]  
![在这里插入图片描述][20210116113827727.png]  
自定义异常

package com.msc.high;
    class MyException extends Exception{ 
        public MyException(String msg){ 
            super("msg") ;
        }
    }
    class Haha{ 
        public static void print(int num) throws Exception{ 
            if(num > 10) throw  new MyException("大于10") ;
            else System.out.println("小于10");
        }
    }
    public class ExceptionDemo { 
        public static void main(String[] args) throws Exception { 
            Haha.print(1);
        }
    }

![在这里插入图片描述][20210116114848157.png]  
**断言**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70 1]

![在这里插入图片描述][20210116121125895.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]: /images/20221119/e2c8635c0b36448eaf23aa69d513f61f.png
[20210116112940588.png]: /images/20221119/f5659186aad34a31a699ef27c553c7c0.png
[20210116113814494.png]: /images/20221119/044e2e842c25458bb230d5afc7033bef.png
[20210116113827727.png]: /images/20221119/c45e89448dc54f0aba7cbd536495346a.png
[20210116114848157.png]: /images/20221119/8f2853c99eb542b0b617200d92421179.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70 1]: /images/20221119/c48ebbe043aa47889a7043edc5cbeacf.png
[20210116121125895.png]: /images/20221119/db68aee11ebf435cb73b22bcff1ec340.png