Exception handling exception

1, Throw an exception
①, Throw and catch exceptions in methods

// In the main function 
        try{
      new A().test(1,0);}
        catch (ArithmeticException e){
    
            e.printStackTrace();
        }
        
// Suppose in this method , Can't handle this exception , Method will actively throw an exception 
    // Method and then catch the exception in the main function to ensure the normal operation of the program 
    public void test(int a ,int b) throws ArithmeticException{
    
     if(b==0){
    
    throw new ArithmeticException(); // Actively throw an exception   Generally used in methods 
}

②, Exceptions that may be encountered during program execution , Direct selling

if(b==0){
    
    throw new ArithmeticException(); // Actively throw an exception   Generally used in methods 
}

2, Capture exception
>VirtulMachineError
The order Throwable>Error>AWTError
>Exception>IOExeception
>RUNtimeException

 //Ctrl+Alt+T  Can quickly generate exception capture mechanism 
        try {
    
            System.out.println(a/b);
        } catch (Exception e) {
    
            e.printStackTrace();// Print the captured stack information 
        } finally {
    
        }
 // Suppose that to catch multiple exceptions, the order needs to be from small to large 
        try{
    
            new demo01().a();
        }catch (Error e){
    
            System.out.println(" Divisor cannot be zero ");
        }catch ( Exception e){
    
            System.out.println("Exception");
        }
        catch (Throwable e){
    
            System.out.println("Throwable");
        }
        //finally Can don't 
        finally {
    
            System.out.println("finally");
        }

3, Custom exception
In order to implement some operations that are not exceptions but are conditional

// Define a variable to receive values >10 The abnormal 
    private int detail;
    // Constructors 
    public MyException(int a){
    
        this.detail=a;
    }

    //toString : Abnormal print information 
    @Override
    public String toString() {
    
        return "MyException{"+detail +'}';
    }
-------------------------
public class Test {
    
    // There may be abnormal methods 
    static void test(int a){
    
        System.out.println(" The parameter passed is "+a);
        if(a>10){
    
            try {
    
                throw new MyException(a);
            } catch (MyException e) {
    
                e.printStackTrace();
            }
        }
        System.out.println("OK");
    }

    public static void main(String[] args) {
    
        test(11);
    }

4, Abnormal summary
1, In multiple exceptions, you can add one at the end catch(Exception) To handle possible missing exceptions
2, Try to deal with exceptions , Do not call simply printStackTrace() To print out
3, Try to add finally Statement block to release some occupied resources