Java example source code file (ExceptionUtilsTest.java)

This example Java source code file (ExceptionUtilsTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

base, bytearrayoutputstream, exception, exceptionwithcause, illegalargumentexception, list, nestableexception, printstream, printwriter, reflection, string, stringwriter, suppresswarnings, test, throwable, util

The ExceptionUtilsTest.java Java example source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang3.exception;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.util.List;

import org.apache.commons.lang3.test.NotVisibleExceptionFactory;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

/**
 * Tests {@link org.apache.commons.lang3.exception.ExceptionUtils}.
 * @since 1.0
 */
public class ExceptionUtilsTest {
    
    private NestableException nested;
    private Throwable withCause;
    private Throwable withoutCause;
    private Throwable jdkNoCause;
    private ExceptionWithCause cyclicCause;
    private Throwable notVisibleException;


    @Before
    public void setUp() {
        withoutCause = createExceptionWithoutCause();
        nested = new NestableException(withoutCause);
        withCause = new ExceptionWithCause(nested);
        jdkNoCause = new NullPointerException();
        final ExceptionWithCause a = new ExceptionWithCause(null);
        final ExceptionWithCause b = new ExceptionWithCause(a);
        a.setCause(b);
        cyclicCause = new ExceptionWithCause(a);
        notVisibleException = NotVisibleExceptionFactory.createException(withoutCause);
    }


    @After
    public void tearDown() throws Exception {
        withoutCause = null;
        nested = null;
        withCause = null;
        jdkNoCause = null;
        cyclicCause = null;
        notVisibleException = null;
    }

    //-----------------------------------------------------------------------
    private Throwable createExceptionWithoutCause() {
        try {
            throw new ExceptionWithoutCause();
        } catch (final Throwable t) {
            return t;
        }
    }

    private Throwable createExceptionWithCause() {
        try {
            try {
                throw new ExceptionWithCause(createExceptionWithoutCause());
            } catch (final Throwable t) {
                throw new ExceptionWithCause(t);
            }
        } catch (final Throwable t) {
            return t;
        }
    }

    //-----------------------------------------------------------------------
    
    @Test
    public void testConstructor() {
        assertNotNull(new ExceptionUtils());
        final Constructor<?>[] cons = ExceptionUtils.class.getDeclaredConstructors();
        assertEquals(1, cons.length);
        assertTrue(Modifier.isPublic(cons[0].getModifiers()));
        assertTrue(Modifier.isPublic(ExceptionUtils.class.getModifiers()));
        assertFalse(Modifier.isFinal(ExceptionUtils.class.getModifiers()));
    }
    
    //-----------------------------------------------------------------------
    @SuppressWarnings("deprecation") // Specifically tests the deprecated methods
    @Test
    public void testGetCause_Throwable() {
        assertSame(null, ExceptionUtils.getCause(null));
        assertSame(null, ExceptionUtils.getCause(withoutCause));
        assertSame(withoutCause, ExceptionUtils.getCause(nested));
        assertSame(nested, ExceptionUtils.getCause(withCause));
        assertSame(null, ExceptionUtils.getCause(jdkNoCause));
        assertSame(cyclicCause.getCause(), ExceptionUtils.getCause(cyclicCause));
        assertSame(((ExceptionWithCause) cyclicCause.getCause()).getCause(), ExceptionUtils.getCause(cyclicCause.getCause()));
        assertSame(cyclicCause.getCause(), ExceptionUtils.getCause(((ExceptionWithCause) cyclicCause.getCause()).getCause()));
        assertSame(withoutCause, ExceptionUtils.getCause(notVisibleException));
    }

    @SuppressWarnings("deprecation") // Specifically tests the deprecated methods
    @Test
    public void testGetCause_ThrowableArray() {
        assertSame(null, ExceptionUtils.getCause(null, null));
        assertSame(null, ExceptionUtils.getCause(null, new String[0]));

        // not known type, so match on supplied method names
        assertSame(nested, ExceptionUtils.getCause(withCause, null));  // default names
        assertSame(null, ExceptionUtils.getCause(withCause, new String[0]));
        assertSame(null, ExceptionUtils.getCause(withCause, new String[] {null}));
        assertSame(nested, ExceptionUtils.getCause(withCause, new String[] {"getCause"}));
        
        // not known type, so match on supplied method names
        assertSame(null, ExceptionUtils.getCause(withoutCause, null));
        assertSame(null, ExceptionUtils.getCause(withoutCause, new String[0]));
        assertSame(null, ExceptionUtils.getCause(withoutCause, new String[] {null}));
        assertSame(null, ExceptionUtils.getCause(withoutCause, new String[] {"getCause"}));
        assertSame(null, ExceptionUtils.getCause(withoutCause, new String[] {"getTargetException"}));
    }

    @Test
    public void testGetRootCause_Throwable() {
        assertSame(null, ExceptionUtils.getRootCause(null));
        assertSame(null, ExceptionUtils.getRootCause(withoutCause));
        assertSame(withoutCause, ExceptionUtils.getRootCause(nested));
        assertSame(withoutCause, ExceptionUtils.getRootCause(withCause));
        assertSame(null, ExceptionUtils.getRootCause(jdkNoCause));
        assertSame(((ExceptionWithCause) cyclicCause.getCause()).getCause(), ExceptionUtils.getRootCause(cyclicCause));
    }

    //-----------------------------------------------------------------------
    @Test
    public void testGetThrowableCount_Throwable() {
        assertEquals(0, ExceptionUtils.getThrowableCount(null));
        assertEquals(1, ExceptionUtils.getThrowableCount(withoutCause));
        assertEquals(2, ExceptionUtils.getThrowableCount(nested));
        assertEquals(3, ExceptionUtils.getThrowableCount(withCause));
        assertEquals(1, ExceptionUtils.getThrowableCount(jdkNoCause));
        assertEquals(3, ExceptionUtils.getThrowableCount(cyclicCause));
    }

    //-----------------------------------------------------------------------
    @Test
    public void testGetThrowables_Throwable_null() {
        assertEquals(0, ExceptionUtils.getThrowables(null).length);
    }

    @Test
    public void testGetThrowables_Throwable_withoutCause() {
        final Throwable[] throwables = ExceptionUtils.getThrowables(withoutCause);
        assertEquals(1, throwables.length);
        assertSame(withoutCause, throwables[0]);
    }

    @Test
    public void testGetThrowables_Throwable_nested() {
        final Throwable[] throwables = ExceptionUtils.getThrowables(nested);
        assertEquals(2, throwables.length);
        assertSame(nested, throwables[0]);
        assertSame(withoutCause, throwables[1]);
    }

    @Test
    public void testGetThrowables_Throwable_withCause() {
        final Throwable[] throwables = ExceptionUtils.getThrowables(withCause);
        assertEquals(3, throwables.length);
        assertSame(withCause, throwables[0]);
        assertSame(nested, throwables[1]);
        assertSame(withoutCause, throwables[2]);
    }

    @Test
    public void testGetThrowables_Throwable_jdkNoCause() {
        final Throwable[] throwables = ExceptionUtils.getThrowables(jdkNoCause);
        assertEquals(1, throwables.length);
        assertSame(jdkNoCause, throwables[0]);
    }

    @Test
    public void testGetThrowables_Throwable_recursiveCause() {
        final Throwable[] throwables = ExceptionUtils.getThrowables(cyclicCause);
        assertEquals(3, throwables.length);
        assertSame(cyclicCause, throwables[0]);
        assertSame(cyclicCause.getCause(), throwables[1]);
        assertSame(((ExceptionWithCause) cyclicCause.getCause()).getCause(), throwables[2]);
    }

    //-----------------------------------------------------------------------
    @Test
    public void testGetThrowableList_Throwable_null() {
        final List<?> throwables = ExceptionUtils.getThrowableList(null);
        assertEquals(0, throwables.size());
    }

    @Test
    public void testGetThrowableList_Throwable_withoutCause() {
        final List<?> throwables = ExceptionUtils.getThrowableList(withoutCause);
        assertEquals(1, throwables.size());
        assertSame(withoutCause, throwables.get(0));
    }

    @Test
    public void testGetThrowableList_Throwable_nested() {
        final List<?> throwables = ExceptionUtils.getThrowableList(nested);
        assertEquals(2, throwables.size());
        assertSame(nested, throwables.get(0));
        assertSame(withoutCause, throwables.get(1));
    }

    @Test
    public void testGetThrowableList_Throwable_withCause() {
        final List<?> throwables = ExceptionUtils.getThrowableList(withCause);
        assertEquals(3, throwables.size());
        assertSame(withCause, throwables.get(0));
        assertSame(nested, throwables.get(1));
        assertSame(withoutCause, throwables.get(2));
    }

    @Test
    public void testGetThrowableList_Throwable_jdkNoCause() {
        final List<?> throwables = ExceptionUtils.getThrowableList(jdkNoCause);
        assertEquals(1, throwables.size());
        assertSame(jdkNoCause, throwables.get(0));
    }

    @Test
    public void testGetThrowableList_Throwable_recursiveCause() {
        final List<?> throwables = ExceptionUtils.getThrowableList(cyclicCause);
        assertEquals(3, throwables.size());
        assertSame(cyclicCause, throwables.get(0));
        assertSame(cyclicCause.getCause(), throwables.get(1));
        assertSame(((ExceptionWithCause) cyclicCause.getCause()).getCause(), throwables.get(2));
    }

    //-----------------------------------------------------------------------
    @Test
    public void testIndexOf_ThrowableClass() {
        assertEquals(-1, ExceptionUtils.indexOfThrowable(null, null));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(null, NestableException.class));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, null));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, ExceptionWithCause.class));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, NestableException.class));
        assertEquals(0, ExceptionUtils.indexOfThrowable(withoutCause, ExceptionWithoutCause.class));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(nested, null));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(nested, ExceptionWithCause.class));
        assertEquals(0, ExceptionUtils.indexOfThrowable(nested, NestableException.class));
        assertEquals(1, ExceptionUtils.indexOfThrowable(nested, ExceptionWithoutCause.class));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, null));
        assertEquals(0, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class));
        assertEquals(1, ExceptionUtils.indexOfThrowable(withCause, NestableException.class));
        assertEquals(2, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithoutCause.class));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, Exception.class));
    }

    @Test
    public void testIndexOf_ThrowableClassInt() {
        assertEquals(-1, ExceptionUtils.indexOfThrowable(null, null, 0));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(null, NestableException.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, null));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, ExceptionWithCause.class, 0));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withoutCause, NestableException.class, 0));
        assertEquals(0, ExceptionUtils.indexOfThrowable(withoutCause, ExceptionWithoutCause.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(nested, null, 0));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(nested, ExceptionWithCause.class, 0));
        assertEquals(0, ExceptionUtils.indexOfThrowable(nested, NestableException.class, 0));
        assertEquals(1, ExceptionUtils.indexOfThrowable(nested, ExceptionWithoutCause.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, null));
        assertEquals(0, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class, 0));
        assertEquals(1, ExceptionUtils.indexOfThrowable(withCause, NestableException.class, 0));
        assertEquals(2, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithoutCause.class, 0));

        assertEquals(0, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class, -1));
        assertEquals(0, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class, 0));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class, 1));
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, ExceptionWithCause.class, 9));
        
        assertEquals(-1, ExceptionUtils.indexOfThrowable(withCause, Exception.class, 0));
    }

    //-----------------------------------------------------------------------
    @Test
    public void testIndexOfType_ThrowableClass() {
        assertEquals(-1, ExceptionUtils.indexOfType(null, null));
        assertEquals(-1, ExceptionUtils.indexOfType(null, NestableException.class));
        
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, null));
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, ExceptionWithCause.class));
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, NestableException.class));
        assertEquals(0, ExceptionUtils.indexOfType(withoutCause, ExceptionWithoutCause.class));
        
        assertEquals(-1, ExceptionUtils.indexOfType(nested, null));
        assertEquals(-1, ExceptionUtils.indexOfType(nested, ExceptionWithCause.class));
        assertEquals(0, ExceptionUtils.indexOfType(nested, NestableException.class));
        assertEquals(1, ExceptionUtils.indexOfType(nested, ExceptionWithoutCause.class));
        
        assertEquals(-1, ExceptionUtils.indexOfType(withCause, null));
        assertEquals(0, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class));
        assertEquals(1, ExceptionUtils.indexOfType(withCause, NestableException.class));
        assertEquals(2, ExceptionUtils.indexOfType(withCause, ExceptionWithoutCause.class));
        
        assertEquals(0, ExceptionUtils.indexOfType(withCause, Exception.class));
    }

    @Test
    public void testIndexOfType_ThrowableClassInt() {
        assertEquals(-1, ExceptionUtils.indexOfType(null, null, 0));
        assertEquals(-1, ExceptionUtils.indexOfType(null, NestableException.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, null));
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, ExceptionWithCause.class, 0));
        assertEquals(-1, ExceptionUtils.indexOfType(withoutCause, NestableException.class, 0));
        assertEquals(0, ExceptionUtils.indexOfType(withoutCause, ExceptionWithoutCause.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfType(nested, null, 0));
        assertEquals(-1, ExceptionUtils.indexOfType(nested, ExceptionWithCause.class, 0));
        assertEquals(0, ExceptionUtils.indexOfType(nested, NestableException.class, 0));
        assertEquals(1, ExceptionUtils.indexOfType(nested, ExceptionWithoutCause.class, 0));
        
        assertEquals(-1, ExceptionUtils.indexOfType(withCause, null));
        assertEquals(0, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class, 0));
        assertEquals(1, ExceptionUtils.indexOfType(withCause, NestableException.class, 0));
        assertEquals(2, ExceptionUtils.indexOfType(withCause, ExceptionWithoutCause.class, 0));

        assertEquals(0, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class, -1));
        assertEquals(0, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class, 0));
        assertEquals(-1, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class, 1));
        assertEquals(-1, ExceptionUtils.indexOfType(withCause, ExceptionWithCause.class, 9));
        
        assertEquals(0, ExceptionUtils.indexOfType(withCause, Exception.class, 0));
    }

    //-----------------------------------------------------------------------
    @Test
    public void testPrintRootCauseStackTrace_Throwable() throws Exception {
        ExceptionUtils.printRootCauseStackTrace(null);
        // could pipe system.err to a known stream, but not much point as
        // internally this method calls stram method anyway
    }
    
    @Test
    public void testPrintRootCauseStackTrace_ThrowableStream() throws Exception {
        ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
        ExceptionUtils.printRootCauseStackTrace(null, (PrintStream) null);
        ExceptionUtils.printRootCauseStackTrace(null, new PrintStream(out));
        assertEquals(0, out.toString().length());
        
        out = new ByteArrayOutputStream(1024);
        try {
            ExceptionUtils.printRootCauseStackTrace(withCause, (PrintStream) null);
            fail();
        } catch (final IllegalArgumentException ex) {
        }
        
        out = new ByteArrayOutputStream(1024);
        final Throwable cause = createExceptionWithCause();
        ExceptionUtils.printRootCauseStackTrace(cause, new PrintStream(out));
        String stackTrace = out.toString();
        assertTrue(stackTrace.indexOf(ExceptionUtils.WRAPPED_MARKER) != -1);
        
        out = new ByteArrayOutputStream(1024);
        ExceptionUtils.printRootCauseStackTrace(withoutCause, new PrintStream(out));
        stackTrace = out.toString();
        assertTrue(stackTrace.indexOf(ExceptionUtils.WRAPPED_MARKER) == -1);
    }

    @Test
    public void testPrintRootCauseStackTrace_ThrowableWriter() throws Exception {
        StringWriter writer = new StringWriter(1024);
        ExceptionUtils.printRootCauseStackTrace(null, (PrintWriter) null);
        ExceptionUtils.printRootCauseStackTrace(null, new PrintWriter(writer));
        assertEquals(0, writer.getBuffer().length());
        
        writer = new StringWriter(1024);
        try {
            ExceptionUtils.printRootCauseStackTrace(withCause, (PrintWriter) null);
            fail();
        } catch (final IllegalArgumentException ex) {
        }
        
        writer = new StringWriter(1024);
        final Throwable cause = createExceptionWithCause();
        ExceptionUtils.printRootCauseStackTrace(cause, new PrintWriter(writer));
        String stackTrace = writer.toString();
        assertTrue(stackTrace.indexOf(ExceptionUtils.WRAPPED_MARKER) != -1);
        
        writer = new StringWriter(1024);
        ExceptionUtils.printRootCauseStackTrace(withoutCause, new PrintWriter(writer));
        stackTrace = writer.toString();
        assertTrue(stackTrace.indexOf(ExceptionUtils.WRAPPED_MARKER) == -1);
    }

    //-----------------------------------------------------------------------
    @Test
    public void testGetRootCauseStackTrace_Throwable() throws Exception {
        assertEquals(0, ExceptionUtils.getRootCauseStackTrace(null).length);
        
        final Throwable cause = createExceptionWithCause();
        String[] stackTrace = ExceptionUtils.getRootCauseStackTrace(cause);
        boolean match = false;
        for (final String element : stackTrace) {
            if (element.startsWith(ExceptionUtils.WRAPPED_MARKER)) {
                match = true;
                break;
            }
        }
        assertTrue(match);
        
        stackTrace = ExceptionUtils.getRootCauseStackTrace(withoutCause);
        match = false;
        for (final String element : stackTrace) {
            if (element.startsWith(ExceptionUtils.WRAPPED_MARKER)) {
                match = true;
                break;
            }
        }
        assertFalse(match);
    }

    @Test(expected=IllegalArgumentException.class)
    public void testRemoveCommonFrames_ListList() throws Exception {
        ExceptionUtils.removeCommonFrames(null, null);
    }

    @Test
    public void test_getMessage_Throwable() {
        Throwable th = null;
        assertEquals("", ExceptionUtils.getMessage(th));
        
        th = new IllegalArgumentException("Base");
        assertEquals("IllegalArgumentException: Base", ExceptionUtils.getMessage(th));
        
        th = new ExceptionWithCause("Wrapper", th);
        assertEquals("ExceptionUtilsTest.ExceptionWithCause: Wrapper", ExceptionUtils.getMessage(th));
    }

    @Test
    public void test_getRootCauseMessage_Throwable() {
        Throwable th = null;
        assertEquals("", ExceptionUtils.getRootCauseMessage(th));
        
        th = new IllegalArgumentException("Base");
        assertEquals("IllegalArgumentException: Base", ExceptionUtils.getRootCauseMessage(th));
        
        th = new ExceptionWithCause("Wrapper", th);
        assertEquals("IllegalArgumentException: Base", ExceptionUtils.getRootCauseMessage(th));
    }

    //-----------------------------------------------------------------------
    /**
     * Provides a method with a well known chained/nested exception
     * name which matches the full signature (e.g. has a return value
     * of <code>Throwable.
     */
    private static class ExceptionWithCause extends Exception {
        private static final long serialVersionUID = 1L;

        private Throwable cause;

        public ExceptionWithCause(final String str, final Throwable cause) {
            super(str);
            setCause(cause);
        }

        public ExceptionWithCause(final Throwable cause) {
            super();
            setCause(cause);
        }

        @Override
        public Throwable getCause() {
            return cause;
        }

        public void setCause(final Throwable cause) {
            this.cause = cause;
        }
    }

    /**
     * Provides a method with a well known chained/nested exception
     * name which does not match the full signature (e.g. lacks a
     * return value of <code>Throwable.
     */
    private static class ExceptionWithoutCause extends Exception {
        private static final long serialVersionUID = 1L;

       @SuppressWarnings("unused")
        public void getTargetException() {
        }
    }

    // Temporary classes to allow the nested exception code to be removed 
    // prior to a rewrite of this test class. 
    private static class NestableException extends Exception { 
        private static final long serialVersionUID = 1L;

        @SuppressWarnings("unused")
        public NestableException() { super(); }
        public NestableException(final Throwable t) { super(t); }
    }

    @Test
    public void testThrow() {
        Exception expected = new InterruptedException();
        try {
            ExceptionUtils.rethrow(expected);
            Assert.fail("Exception not thrown");
        }
        catch(Exception actual) {
            Assert.assertSame(expected, actual);
        }
    }

    @Test
    public void testCatchTechniques() {
        try {
            throwsCheckedException();
            Assert.fail("Exception not thrown");
        }
        catch(Exception ioe) {
            assertTrue(ioe instanceof IOException);
            assertEquals(1, ExceptionUtils.getThrowableCount(ioe));
        }
        
        try {
            redeclareCheckedException();
            Assert.fail("Exception not thrown");
        }
        catch(IOException ioe) {
            assertEquals(1, ExceptionUtils.getThrowableCount(ioe));
        }
    }

    private static int redeclareCheckedException() throws IOException {
        return throwsCheckedException();
    }

    private static int throwsCheckedException() {
        try {
            throw new IOException();
        } catch (Exception e) {
            return ExceptionUtils.<Integer>rethrow(e);
        }
    }

    public static class TestThrowable extends Throwable {
        private static final long serialVersionUID = 1L;
    }

    @Test
    public void testWrapAndUnwrapError() {
        try {
            ExceptionUtils.wrapAndThrow(new OutOfMemoryError());
            Assert.fail("Error not thrown");
        }
        catch(Throwable t) {
            Assert.assertTrue(ExceptionUtils.hasCause(t, Error.class));
        }
    }

    @Test
    public void testWrapAndUnwrapRuntimeException() {
        try {
            ExceptionUtils.wrapAndThrow(new IllegalArgumentException());
            Assert.fail("RuntimeException not thrown");
        }
        catch(Throwable t) {
            Assert.assertTrue(ExceptionUtils.hasCause(t, RuntimeException.class));
        }
    }

    @Test
    public void testWrapAndUnwrapCheckedException() {
        try {
            ExceptionUtils.wrapAndThrow(new IOException());
            Assert.fail("Checked Exception not thrown");
        }
        catch(Throwable t) {
            Assert.assertTrue(ExceptionUtils.hasCause(t, IOException.class));
        }
    }

    @Test
    public void testWrapAndUnwrapThrowable() {
        try {
            ExceptionUtils.wrapAndThrow(new TestThrowable());
            Assert.fail("Checked Exception not thrown");
        }
        catch(Throwable t) {
            Assert.assertTrue(ExceptionUtils.hasCause(t, TestThrowable.class));
        }
    }
}