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Posted to dev@commons.apache.org by dl...@apache.org on 2002/08/13 20:05:58 UTC
cvs commit: jakarta-commons/lang/src/test/org/apache/commons/lang/exception ExceptionUtilsTestCase.java ExceptionTestSuite.java
dlr 2002/08/13 11:05:58
Modified: lang/src/test/org/apache/commons/lang/exception
ExceptionTestSuite.java
Added: lang/src/java/org/apache/commons/lang/exception
ExceptionUtils.java
lang/src/test/org/apache/commons/lang/exception
ExceptionUtilsTestCase.java
Log:
Added a utility for examining Throwable objects, as proposed by Costin
<co...@covalent.net> and Henri Yandell <ba...@apache.org>. Comes complete
with a full suite of tests for initial functionality.
Revision Changes Path
1.1 jakarta-commons/lang/src/java/org/apache/commons/lang/exception/ExceptionUtils.java
Index: ExceptionUtils.java
===================================================================
package org.apache.commons.lang.exception;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Utility routines for manipulating <code>Throwable</code> objects.
*
* @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
* @since 1.0
*/
public class ExceptionUtils
{
/**
* The name of the <code>getCause()</code> method.
*/
protected static final String CAUSE_METHOD_NAME = "getCause";
/**
* The parameters of the <code>getCause()</code> method.
*/
protected static final Object[] CAUSE_METHOD_PARAMS = {};
/**
* Constructs a new <code>ExceptionUtils</code>. Protected to
* discourage instantiation.
*/
protected ExceptionUtils()
{
}
/**
* Introspects the specified <code>Throwable</code> for a
* <code>getCause()</code> method (standard as of JDK 1.4, and
* part of the {@link
* org.apache.commons.lang.exception.NestableException} API),
* extracting and returning the cause of the exception.
* Otherwise, returns <code>null</code>.
* <p>
* TODO: Examine for a "detail" public member attribute from
* java.rmi.RemoteException.
*
* @param t The exception to introspect for a cause.
* @return The cause of the <code>Throwable</code>.
*/
public static Throwable getCause(Throwable t)
{
Throwable cause = null;
if (t instanceof NestableException)
{
cause = ((NestableException) t).getCause();
}
else if (t instanceof NestableRuntimeException)
{
cause = ((NestableRuntimeException) t).getCause();
}
else
{
Method getCause = null;
Class c = t.getClass();
try
{
getCause = c.getMethod(CAUSE_METHOD_NAME, null);
}
catch (NoSuchMethodException ignored)
{
}
catch (SecurityException ignored)
{
}
if (getCause != null && getCause.getReturnType() == Throwable.class)
{
try
{
cause = (Throwable) getCause.invoke(t, CAUSE_METHOD_PARAMS);
}
catch (IllegalAccessException ignored)
{
}
catch (IllegalArgumentException ignored)
{
}
catch (InvocationTargetException ignored)
{
}
}
}
return cause;
}
/**
* Walks through the exception chain to the last element -- the
* "root" of the tree -- using {@link #getCause(Throwable)}, and
* returns that exception.
*
* @return The root cause of the <code>Throwable</code>.
* @see #getCause(Throwable)
*/
public static Throwable getRootCause(Throwable t)
{
Throwable cause = getCause(t);
if (cause != null)
{
t = cause;
while ((t = getCause(t)) != null)
{
cause = t;
}
}
return cause;
}
}
1.3 +1 -0 jakarta-commons/lang/src/test/org/apache/commons/lang/exception/ExceptionTestSuite.java
Index: ExceptionTestSuite.java
===================================================================
RCS file: /home/cvs/jakarta-commons/lang/src/test/org/apache/commons/lang/exception/ExceptionTestSuite.java,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -u -r1.2 -r1.3
--- ExceptionTestSuite.java 26 Jul 2002 19:46:38 -0000 1.2
+++ ExceptionTestSuite.java 13 Aug 2002 18:05:58 -0000 1.3
@@ -88,6 +88,7 @@
suite.addTest(NestableDelegateTestCase.suite());
suite.addTest(NestableExceptionTestCase.suite());
suite.addTest(NestableRuntimeExceptionTestCase.suite());
+ suite.addTest(ExceptionUtilsTestCase.suite());
return suite;
}
}
1.1 jakarta-commons/lang/src/test/org/apache/commons/lang/exception/ExceptionUtilsTestCase.java
Index: ExceptionUtilsTestCase.java
===================================================================
package org.apache.commons.lang.exception;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
/**
* Tests {@link org.apache.commons.lang.exception.ExceptionUtils}.
*
* @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
* @since 1.0
*/
public class ExceptionUtilsTestCase extends junit.framework.TestCase
{
private NestableException nested;
private Throwable withCause;
private Throwable withoutCause;
public ExceptionUtilsTestCase(String name)
{
super(name);
}
public static Test suite()
{
return new TestSuite(ExceptionUtilsTestCase.class);
}
public void setUp()
{
withoutCause = new ExceptionWithoutCause();
nested = new NestableException(withoutCause);
withCause = new ExceptionWithCause(nested);
}
public void testGetCause()
{
assertNull(ExceptionUtils.getCause(withoutCause));
assertTrue(ExceptionUtils.getCause(nested) == withoutCause);
assertTrue(ExceptionUtils.getCause(withCause) == nested);
}
public void testGetRootCause()
{
assertNull(ExceptionUtils.getRootCause(withoutCause));
assertTrue(ExceptionUtils.getRootCause(withCause) == withoutCause);
assertTrue(ExceptionUtils.getRootCause(withCause) == withoutCause);
}
private static class ExceptionWithCause extends Exception
{
private Throwable cause;
public ExceptionWithCause(Throwable cause)
{
this.cause = cause;
}
public Throwable getCause()
{
return cause;
}
}
private static class ExceptionWithoutCause extends Exception
{
/**
* Bogus signature.
*/
public void getCause()
{
}
}
}
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