Java 6_Exception handling

An exception object is created when an error occurs
It tells you what error occurred
Here are many of the java exceptions

Common Exceptions

ArithmeticException: An arithmetic operation occurs with no answer
         * (Division by Zero)
         * 
         * ClassNotFoundException: A class is called for that doesn't exist
         * 
         * IllegalArgumentException: A method has been passed an illegal argument
         * 
         * IndexOutOfBoundsException: Thrown when an index for an array, string is
         * called for, but doesn't exist
         * 
         * InputMismatchException: (Part of NoSuchElementException) User enters the 
         * wrong data type into a Scanner method
         * 
         * IOException: An I/O operation failed
         */
import java.util.Scanner; // Library that allows us to capture user input
import java.util.*; // Allows me to check for InputMismatchException
import java.io.*; // Allows for system input and output through data streams, serialization and the file system

public class LessonSix {
    
    // Creates a Scanner object that monitors keyboard input
    static Scanner userInput = new Scanner(System.in);
    
    public static void main(String[] args){
        
        divideByZero(2);
        
        
    public static void divideByZero(int a)
    {
        
        try
        {
            // The following throws an error because you can't divide by zero
            // Exception in thread "main" java.lang.ArithmeticException
            System.out.println(a/0);
        }
        
        // If the exception ArithmeticException is thrown the following execute
        catch (ArithmeticException e)
        {
            // Your custom error message
            System.out.println("You can't divide by zero");
            
            // Java's error message for this exception
            System.out.println(e.getMessage());
            
            // Prints the exception name and error message
            System.out.println(e.toString());
            
            // Prints the standard error stack trace
            e.printStackTrace();
        }
        
    }
    

File not found & IO exception

        catch (FileNotFoundException e)
        {
            System.out.println("Sorry I couldn't find that file");
        }
        
        // You can catch numerous exceptions (List most specific first
        catch (IOException e) // Catches any IO Exception
        {
            System.out.println("An unknown IO Error Occured");
        }
        
        /* To ignore an exception do this
         * catch (ClassNotFoundException e)
         * {}
         */
        
        /* Java 7 allows you to catch multiple exceptions at once
         * catch (FileNotFoundException | IOException e)
         * {}
         */
        
        // This will catch any exception (This should always be last)
        catch (Exception e)
        {
            System.out.println("I catch every exception");
        }
        
        // If used finally is always executed whether there was an exception or not
        // It is used for clean up work like closing files and database connections
        finally
        {
            System.out.println("");
        }
java.lang.RuntimeException : exceptions that can be thrown during the normal
         
         * ArithmeticException, ArrayStoreException, BufferOverflowException, 
         * BufferUnderflowException, CannotRedoException, CannotUndoException, 
         * ClassCastException, CMMException, ConcurrentModificationException, 
         * DOMException, EmptyStackException, IllegalArgumentException, 
         * IllegalMonitorStateException, IllegalPathStateException, 
         * IllegalStateException, ImagingOpException, IndexOutOfBoundsException, 
         * MissingResourceException, NegativeArraySizeException, NoSuchElementException, 
         * NullPointerException, ProfileDataException, ProviderException, 
         * RasterFormatException, SecurityException, SystemException, 
         * UndeclaredThrowableException, UnmodifiableSetException, 
         * UnsupportedOperationException

java.lang.Exception : exceptions that are checked for by the java compiler

         * AclNotFoundException, ActivationException, AlreadyBoundException, 
         * ApplicationException, AWTException, BackingStoreException, 
         * BadAttributeValueExpException, BadBinaryOpValueExpException, 
         * BadLocationException, BadStringOperationException, 
         * BrokenBarrierException, CertificateException, ClassNotFoundException, 
         * CloneNotSupportedException, DataFormatException, 
         * DatatypeConfigurationException, DestroyFailedException, 
         * ExecutionException, ExpandVetoException, FontFormatException, 
         * GeneralSecurityException, GSSException, IllegalAccessException, 
         * IllegalClassFormatException, InstantiationException, 
         * InterruptedException, IntrospectionException, 
         * InvalidApplicationException, InvalidMidiDataException, 
         * InvalidPreferencesFormatException, InvalidTargetObjectTypeException, 
         * InvocationTargetException, IOException, JAXBException, JMException, 
         * KeySelectorException, LastOwnerException, LineUnavailableException, 
         * MarshalException, MidiUnavailableException, MimeTypeParseException, 
         * MimeTypeParseException, NamingException, NoninvertibleTransformException, 
         * NoSuchFieldException, NoSuchMethodException, NotBoundException, 
         * NotOwnerException, ParseException, ParserConfigurationException, 
         * PrinterException, PrintException, PrivilegedActionException, 
         * PropertyVetoException, RefreshFailedException, RemarshalException, 
         * RuntimeException, SAXException, ScriptException, ServerNotActiveException, 
         * SOAPException, SQLException, TimeoutException, TooManyListenersException, 
         * TransformerException, TransformException, UnmodifiableClassException, 
         * UnsupportedAudioFileException, UnsupportedCallbackException, 
         * UnsupportedFlavorException, UnsupportedLookAndFeelException, 
         * URIReferenceException, URISyntaxException, UserException, XAException, 
         * XMLParseException, XMLSignatureException, XMLStreamException, XPathException
         */
点赞