exceptionininitializererror.java

来自「This is a resource based on j2me embedde」· Java 代码 · 共 130 行

/*
 * @(#)ExceptionInInitializerError.java	1.19 06/10/13
 *
 * Copyright  1990-2008 Sun Microsystems, Inc. All Rights Reserved.  
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER  
 *   
 * This program is free software; you can redistribute it and/or  
 * modify it under the terms of the GNU General Public License version  
 * 2 only, as published by the Free Software Foundation.   
 *   
 * This program is distributed in the hope that it will be useful, but  
 * WITHOUT ANY WARRANTY; without even the implied warranty of  
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  
 * General Public License version 2 for more details (a copy is  
 * included at /legal/license.txt).   
 *   
 * You should have received a copy of the GNU General Public License  
 * version 2 along with this work; if not, write to the Free Software  
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  
 * 02110-1301 USA   
 *   
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa  
 * Clara, CA 95054 or visit www.sun.com if you need additional  
 * information or have any questions. 
 *
 */

package java.lang;

/**
 * Signals that an unexpected exception has occurred in a static initializer. 
 * An <code>ExceptionInInitializerError</code> is thrown to indicate that an 
 * exception occurred during evaluation of a static initializer or the
 * initializer for a static variable.
 *
 * <p>As of release 1.4, this exception has been retrofitted to conform to
 * the general purpose exception-chaining mechanism.  The "saved throwable
 * object" that may be provided at construction time and accessed via
 * the {@link #getException()} method is now known as the <i>cause</i>,
 * and may be accessed via the {@link Throwable#getCause()} method, as well
 * as the aforementioned "legacy method."
 *
 * @version 1.11, 02/02/00
 *
 * @since   JDK1.1
 */
public class ExceptionInInitializerError extends LinkageError {
    /**
     * Use serialVersionUID from JDK 1.1.X for interoperability
     */
    private static final long serialVersionUID = 1521711792217232256L;

    /**
     * This field holds the exception if the 
     * ExceptionInInitializerError(Throwable thrown) constructor was
     * used to instantiate the object
     * 
     * @serial 
     * 
     */
    private Throwable exception;

    /**
     * Constructs an <code>ExceptionInInitializerError</code> with 
     * <code>null</code> as its detail message string and with no saved
     * throwable object.
     * A detail message is a String that describes this particular exception.
     */
    public ExceptionInInitializerError() {
        initCause(null);  // Disallow subsequent initCause
    }

    /**
     * Constructs a new <code>ExceptionInInitializerError</code> class by 
     * saving a reference to the <code>Throwable</code> object thrown for 
     * later retrieval by the {@link #getException()} method. The detail 
     * message string is set to <code>null</code>.
     *
     * @param thrown The exception thrown
     */
    public ExceptionInInitializerError(Throwable thrown) {
        initCause(null);  // Disallow subsequent initCause
	this.exception = thrown;
    }

    /**
     * Constructs an ExceptionInInitializerError with the specified detail 
     * message string.  A detail message is a String that describes this 
     * particular exception. The detail message string is saved for later 
     * retrieval by the {@link Throwable#getMessage()} method. There is no 
     * saved throwable object. 
     *
     *
     * @param s the detail message
     */
    public ExceptionInInitializerError(String s) {
	super(s);
        initCause(null);  // Disallow subsequent initCause
    }

    /**
     * Returns the exception that occurred during a static initialization that
     * caused this error to be created.
     *
     * <p>This method predates the general-purpose exception chaining facility.
     * The {@link Throwable#getCause()} method is now the preferred means of
     * obtaining this information.
     * 
     * @return the saved throwable object of this 
     *         <code>ExceptionInInitializerError</code>, or <code>null</code> 
     *         if this <code>ExceptionInInitializerError</code> has no saved 
     *         throwable object. 
     */
    public Throwable getException() {
	return exception;
    }

    /**
     * Returns the cause of this error (the exception that occurred
     * during a static initialization that caused this error to be created).
     * 
     * @return  the cause of this error or <code>null</code> if the
     *          cause is nonexistent or unknown.
     * @since   1.4
     */
    public Throwable getCause() {
	return exception;
    }
}