[JAVA API] java.lang.Exception

Figure 1: The base of the Java exception hierarchy.Types in red, and their subclasses, are unchecked .

 

예외처리(try~catch) 사용 예제

import java.io.*;
import java.util.*;

class Ex109_tryCatch 
{
	public static void main(String[] args) throws IOException
	{
		//Ex109_tryCatch.java
		//다중 예외처리
		//다중 catch문

		m1();

	}

	public static void m1() {

		try {

			//ArrayIndexOutOfBoundsException
			int[] ns = {10, 20, 30};
			//System.out.println(ns[5]);


			//NullPointerException
			Random rnd = new Random();
			rnd = null;	//객체 소멸
			//int num = rnd.nextInt(10);

			
			//ArithmeticException
			int result = 100 / 0;

		}
		catch(ArrayIndexOutOfBoundsException e)
		{
			System.out.println("ArrayIndexOutOfBoundsException 에러");
		}
		catch(NullPointerException e) 
		{
			System.out.println("NullPointerException 에러");
		}
		catch(ArithmeticException e) 
		{
			System.out.println("ArithmeticException 에러");
		}
	
	}


}

 

예외 던지기(강제 발생) 사용 예제

//예외 던지기
//	- 문법상으로 예외가 아닌데 예외로 처리해야 할 경우

class Ex110_throwException 
{
	public static void main(String[] args)
	{
		//Ex110_throwException.java

		//3의 배수만 입력
		int num = 4;

		if(num % 3 == 0)
			System.out.println("정상 업무 처리");
		else
			System.out.println("예외처리");


		try
		{
			if(num%3!=0)	//예외처리해야하는 경우
			{
				//예외 던지기 - 중단하고 catch 제어이동
				throw new Exception("3의 배수만 가능");
			}
			System.out.println("정상 업무 처리");
		}
		catch(Exception e)
		{
			System.out.println("처리 : "+e.getMessage());
		}
	}
}

 

사용자예외처리 사용 예제

class Ex111_tryCatch 
{
	public static void main(String[] args)
	{
		//Ex111_tryCatch.java
		//쇼핑몰
		//

		System.out.println("제품 주문...");

		try
		{
			//제품 파손 접수 -> 예외 발생
			throw new MyException("A001");
		}
		catch(MyException e)
		{
			System.out.printf("발생코드 : %s%n내선번호 : %s%n",
				e.toString(), e.getNumber());
		}
	}
}


//예외클래스 정의(사용자 예외 객체)
//	- try~catch문의 관리를 받으려면 Exception을 상속받아야함
class MyException extends Exception
{
	public static final String A001 = "100";	//배송중 제품 파손
	public static final String A002 = "110";	//배송중 날짜 지연
	public static final String A003 = "120";	//배송중 제품 수령 불가
	public static final String B001 = "200";	//사용중 제품 불량
	public static final String B002 = "210";	//사용중 제품 오작동

	private String code;

	public MyException(String code) {
		this.code = code;
	}
	
	//재정의
	public String toString() {
		return this.code;
	}

	public String getNumber()
	{
		if(this.code.equals("A001"))
			return A001;
		else if(this.code.equals("A002"))
			return A002;
		else if(this.code.equals("A003"))
			return A003;
		else if(this.code.equals("B001"))
			return B001;
		else if(this.code.equals("B002"))
			return B002;

		return null;
	}
}

 

 

java.lang

Class Exception

• java.lang.Object
• • java.lang.Throwable
  • • java.lang.Exception

• All Implemented Interfaces:

  Serializable

  Direct Known Subclasses:

  AclNotFoundException, ActivationException, AlreadyBoundException, ApplicationException, AWTException, BackingStoreException, BadAttributeValueExpException, BadBinaryOpValueExpException, BadLocationException, BadStringOperationException, BrokenBarrierException, CertificateException, CloneNotSupportedException, DataFormatException, DatatypeConfigurationException, DestroyFailedException, ExecutionException, ExpandVetoException, FontFormatException, GeneralSecurityException, GSSException, IllegalClassFormatException, InterruptedException, IntrospectionException, InvalidApplicationException, InvalidMidiDataException, InvalidPreferencesFormatException, InvalidTargetObjectTypeException, IOException, JAXBException, JMException, KeySelectorException, LastOwnerException, LineUnavailableException, MarshalException, MidiUnavailableException, MimeTypeParseException, MimeTypeParseException, NamingException, NoninvertibleTransformException, NotBoundException, NotOwnerException, ParseException, ParserConfigurationException, PrinterException, PrintException, PrivilegedActionException, PropertyVetoException, ReflectiveOperationException, 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

  ---

  
  

  public class Exception
  extends Throwable

  The class Exception and its subclasses are a form of Throwable that indicates conditions that a reasonable application might want to catch.

  The class Exception and any subclasses that are not also subclasses of RuntimeException are checked exceptions. Checked exceptions need to be declared in a method or constructor's throws clause if they can be thrown by the execution of the method or constructor and propagate outside the method or constructor boundary.

  Since:

  JDK1.0

  See Also:

  Error, Serialized Form

  See The Java™ Language Specification:

  11.2 Compile-Time Checking of Exceptions

• • Constructor Summary

    Constructors 

    Modifier	Constructor and Description
    	Exception() Constructs a new exception with null as its detail message.
    	Exception(String message) Constructs a new exception with the specified detail message.
    	Exception(String message, Throwable cause) Constructs a new exception with the specified detail message and cause.
    protected	Exception(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) Constructs a new exception with the specified detail message, cause, suppression enabled or disabled, and writable stack trace enabled or disabled.
    	Exception(Throwable cause) Constructs a new exception with the specified cause and a detail message of (cause==null ? null : cause.toString()) (which typically contains the class and detail message of cause).

  • Method Summary

    • Methods inherited from class java.lang.Throwable

      addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

    • Methods inherited from class java.lang.Object

      clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait