org.eclipse.swt.SWTError Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2008, 2012 IBM Corporation, Gerhardt Informatics Kft. and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Gerhardt Informatics Kft. - GEFGWT port
*******************************************************************************/
package org.eclipse.swt;
import org.eclipse.swt.internal.Library;
/**
* This error is thrown whenever an unrecoverable error occurs internally in
* SWT. The message text and error code provide a further description of the
* problem. The exception has a throwable field which holds the
* underlying throwable that caused the problem (if this information is
* available (i.e. it may be null)).
*
* SWTErrors are thrown when something fails internally which either leaves SWT
* in an unknown state (eg. the o/s call to remove an item from a list returns
* an error code) or when SWT is left in a known-to-be-unrecoverable state (eg.
* it runs out of callback resources). SWTErrors should not occur in typical
* programs, although "high reliability" applications should still catch them.
*
*
* This class also provides support methods used by SWT to match error codes to
* the appropriate exception class (SWTError, SWTException, or
* IllegalArgumentException) and to provide human readable strings for SWT error
* codes.
*
*
* @see SWTException
* @see SWT#error(int)
* @see Sample code and further
* information
*/
public class SWTError extends Error {
/**
* The SWT error code, one of SWT.ERROR_*.
*/
public int code;
/**
* The underlying throwable that caused the problem, or null if this
* information is not available.
*/
public Throwable throwable;
static final long serialVersionUID = 3833467327105808433L;
/**
* Constructs a new instance of this class with its stack trace filled in.
* The error code is set to an unspecified value.
*/
public SWTError() {
this(SWT.ERROR_UNSPECIFIED);
}
/**
* Constructs a new instance of this class with its stack trace and message
* filled in. The error code is set to an unspecified value. Specifying
* null as the message is equivalent to specifying an empty
* string.
*
* @param message
* the detail message for the exception
*/
public SWTError(String message) {
this(SWT.ERROR_UNSPECIFIED, message);
}
/**
* Constructs a new instance of this class with its stack trace and error
* code filled in.
*
* @param code
* the SWT error code
*/
public SWTError(int code) {
this(code, SWT.findErrorText(code));
}
/**
* Constructs a new instance of this class with its stack trace, error code
* and message filled in. Specifying null as the message is
* equivalent to specifying an empty string.
*
* @param code
* the SWT error code
* @param message
* the detail message for the exception
*/
public SWTError(int code, String message) {
super(message);
this.code = code;
}
/**
* Returns the underlying throwable that caused the problem, or null if this
* information is not available.
*
* NOTE: This method overrides Throwable.getCause() that was added to
* JDK1.4. It is necessary to override this method in order for inherited
* printStackTrace() methods to work.
*
*
* @return the underlying throwable
*
* @since 3.1
*/
public Throwable getCause() {
return throwable;
}
/**
* Returns the string describing this SWTError object.
*
* It is combined with the message string of the Throwable which caused this
* SWTError (if this information is available).
*
*
* @return the error message string of this SWTError object
*/
public String getMessage() {
if (throwable == null)
return super.getMessage();
return super.getMessage() + " (" + throwable.toString() + ")"; //$NON-NLS-1$ //$NON-NLS-2$
}
/**
* Outputs a printable representation of this error's stack trace on the
* standard error stream.
*
* Note: printStackTrace(PrintStream) and printStackTrace(PrintWriter) are
* not provided in order to maintain compatibility with CLDC.
*
*/
public void printStackTrace() {
super.printStackTrace();
if (Library.JAVA_VERSION < Library.JAVA_VERSION(1, 4, 0)
&& throwable != null) {
System.err.println("*** Stack trace of contained error ***"); //$NON-NLS-1$
throwable.printStackTrace();
}
}
}