exceptionutils.java

人力资源管理系统主要包括：人员管理、招聘管理、培训管理、奖惩管理和薪金管理五大管理模块。

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002-2003 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 acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements 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 [e-mail].
 *
 * 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/>.
 */
package net.sf.hibernate.exception;

import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.StringTokenizer;

import net.sf.hibernate.util.ArrayHelper;

/**
 * <p>Provides utilities for manipulating and examining 
 * <code>Throwable</code> objects.</p>
 *
 * @author <a href="mailto:[e-mail]">Daniel Rall</a>
 * @author Dmitri Plotnikov
 * @author Stephen Colebourne
 * @author <a href="mailto:[e-mail]">Gary Gregory</a>
 * @author Pete Gieser
 * @since 1.0
 * @version $Id: ExceptionUtils.java,v 1.1.2.4 2003/10/28 22:10:02 oneovthafew Exp $
 */
public final class ExceptionUtils {
    
	private static final String LINE_SEPARATOR = System.getProperty("line.separator");

    /**
     * <p>Used when printing stack frames to denote the start of a
     * wrapped exception.</p>
     *
     * <p>Package private for accessibility by test suite.</p>
     */
    static final String WRAPPED_MARKER = " [wrapped] ";

    /**
     * <p>The names of methods commonly used to access a wrapped exception.</p>
     */
    private static final String[] CAUSE_METHOD_NAMES = {
        "getCause",
        "getNextException",
        "getTargetException",
        "getException",
        "getSourceException",
        "getRootCause",
        "getCausedByException",
        "getNested"
    };

    /**
     * <p>The Method object for JDK1.4 getCause.</p>
     */
    private static final Method THROWABLE_CAUSE_METHOD;
    static {
        Method getCauseMethod;
        try {
            getCauseMethod = Throwable.class.getMethod("getCause", null);
        } 
        catch (Exception e) {
            getCauseMethod = null;
        }
        THROWABLE_CAUSE_METHOD = getCauseMethod;
    }
    
    private ExceptionUtils() {
    }

    //-----------------------------------------------------------------------
    /**
     * <p>Adds to the list of method names used in the search for <code>Throwable</code>
     * objects.</p>
     * 
     * @param methodName  the methodName to add to the list, <code>null</code>
     *  and empty strings are ignored
     * @since 2.0
     */
    /*public static void addCauseMethodName(String methodName) {
        if ( StringHelper.isNotEmpty(methodName) ) {
            List list = new ArrayList( Arrays.asList(CAUSE_METHOD_NAMES );
            list.add(methodName);
            CAUSE_METHOD_NAMES = (String[]) list.toArray(new String[list.size()]);
        }
    }*/

    /**
     * <p>Introspects the <code>Throwable</code> to obtain the cause.</p>
     * 
     * <p>The method searches for methods with specific names that return a 
     * <code>Throwable</code> object. This will pick up most wrapping exceptions,
     * including those from JDK 1.4, and
     * {@link org.apache.commons.lang.exception.NestableException NestableException}.
     * The method names can be added to using {@link #addCauseMethodName(String)}.</p>
     *
     * <p>The default list searched for are:</p>
     * <ul>
     *  <li><code>getCause()</code></li>
     *  <li><code>getNextException()</code></li>
     *  <li><code>getTargetException()</code></li>
     *  <li><code>getException()</code></li>
     *  <li><code>getSourceException()</code></li>
     *  <li><code>getRootCause()</code></li>
     *  <li><code>getCausedByException()</code></li>
     *  <li><code>getNested()</code></li>
     * </ul>
     * 
     * <p>In the absence of any such method, the object is inspected for a
     * <code>detail</code> field assignable to a <code>Throwable</code>.</p>
     * 
     * <p>If none of the above is found, returns <code>null</code>.</p>
     *
     * @param throwable  the throwable to introspect for a cause, may be null
     * @return the cause of the <code>Throwable</code>,
     *  <code>null</code> if none found or null throwable input
     */
    public static Throwable getCause(Throwable throwable) {
        return getCause(throwable, CAUSE_METHOD_NAMES);
    }

    /**
     * <p>Introspects the <code>Throwable</code> to obtain the cause.</p>
     * 
     * <ol>
     * <li>Try known exception types.</li>
     * <li>Try the supplied array of method names.</li>
     * <li>Try the field 'detail'.</li>
     * </ol>
     * 
     * <p>A <code>null</code> set of method names means use the default set.
     * A <code>null</code> in the set of method names will be ignored.</p>
     *
     * @param throwable  the throwable to introspect for a cause, may be null
     * @param methodNames  the method names, null treated as default set
     * @return the cause of the <code>Throwable</code>,
     *  <code>null</code> if none found or null throwable input
     */
    public static Throwable getCause(Throwable throwable, String[] methodNames) {
        if (throwable == null) {
            return null;
        }
        Throwable cause = getCauseUsingWellKnownTypes(throwable);
        if (cause == null) {
            if (methodNames == null) {
                methodNames = CAUSE_METHOD_NAMES;
            }
            for (int i = 0; i < methodNames.length; i++) {
                String methodName = methodNames[i];
                if (methodName != null) {
                    cause = getCauseUsingMethodName(throwable, methodName);
                    if (cause != null) {
                        break;
                    }
                }
            }

            if (cause == null) {
                cause = getCauseUsingFieldName(throwable, "detail");
            }
        }
        return cause;
    }

    /**
     * <p>Introspects the <code>Throwable</code> to obtain the root cause.</p>
     * 
     * <p>This method walks through the exception chain to the last element,
     * "root" of the tree, using {@link #getCause(Throwable)}, and
     * returns that exception.</p>
     *
     * @param throwable  the throwable to get the root cause for, may be null
     * @return the root cause of the <code>Throwable</code>,
     *  <code>null</code> if none found or null throwable input
     */
    public static Throwable getRootCause(Throwable throwable) {
        Throwable cause = getCause(throwable);
        if (cause != null) {
            throwable = cause;
            while ( ( throwable = getCause(throwable) ) != null ) {
                cause = throwable;
            }
        }
        return cause;
    }

    /**
     * <p>Finds a <code>Throwable</code> for known types.</p>
     * 
     * <p>Uses <code>instanceof</code> checks to examine the exception,
     * looking for well known types which could contain chained or
     * wrapped exceptions.</p>
     *
     * @param throwable  the exception to examine
     * @return the wrapped exception, or <code>null</code> if not found
     */
    private static Throwable getCauseUsingWellKnownTypes(Throwable throwable) {
        if (throwable instanceof Nestable) {
            return ( (Nestable) throwable ).getCause();
        } 
        else if (throwable instanceof SQLException) {
            return ( (SQLException) throwable ).getNextException();
        } 
        else if (throwable instanceof InvocationTargetException) {
            return ( (InvocationTargetException) throwable ).getTargetException();
        }
        else {
            return null;
        }
    }
    
    /**
     * <p>Finds a <code>Throwable</code> by method name.</p>
     * 
     * @param throwable  the exception to examine
     * @param methodName  the name of the method to find and invoke
     * @return the wrapped exception, or <code>null</code> if not found
     */
    private static Throwable getCauseUsingMethodName(Throwable throwable, String methodName) {
        Method method = null;
        try {
            method = throwable.getClass().getMethod(methodName, null);
        } 
        catch (NoSuchMethodException ignored) {} 
        catch (SecurityException ignored) {}

        if ( method != null && Throwable.class.isAssignableFrom( method.getReturnType() ) ) {
            try {
                return (Throwable) method.invoke(throwable, ArrayHelper.EMPTY_OBJECT_ARRAY);
            } 
            catch (IllegalAccessException ignored) {} 
            catch (IllegalArgumentException ignored) {} 
            catch (InvocationTargetException ignored) {}
        }
        return null;
    }

    /**
     * <p>Finds a <code>Throwable</code> by field name.</p>
     * 
     * @param throwable  the exception to examine
     * @param fieldName  the name of the attribute to examine
     * @return the wrapped exception, or <code>null</code> if not found
     */
    private static Throwable getCauseUsingFieldName(Throwable throwable, String fieldName) {
        Field field = null;
        try {
            field = throwable.getClass().getField(fieldName);
        } 
        catch (NoSuchFieldException ignored) {} 
        catch (SecurityException ignored) {}

        if ( field != null && Throwable.class.isAssignableFrom( field.getType() ) ) {
            try {
                return (Throwable) field.get(throwable);
            } 
            catch (IllegalAccessException ignored) {} 
            catch (IllegalArgumentException ignored) {}
        }
        return null;
    }

    //-----------------------------------------------------------------------
    /**
     * <p>Checks if the Throwable class has a <code>getCause</code> method.</p>
     * 
     * <p>This is true for JDK 1.4 and above.</p>
     * 
     * @return true if Throwable is nestable
     * @since 2.0
     */
    public static boolean isThrowableNested() {
        return (THROWABLE_CAUSE_METHOD != null);
    }
    
    /**
     * <p>Checks whether this <code>Throwable</code> class can store a cause.</p>
     * 
     * <p>This method does <b>not</b> check whether it actually does store a cause.<p>
     *
     * @param throwable  the <code>Throwable</code> to examine, may be null
     * @return boolean <code>true</code> if nested otherwise <code>false</code>
     * @since 2.0
     */
    public static boolean isNestedThrowable(Throwable throwable) {
        if (throwable == null) {
            return false;
        }

        if (throwable instanceof Nestable) {
            return true;
        } 
        else if (throwable instanceof SQLException) {
            return true;
        } 
        else if (throwable instanceof InvocationTargetException) {
            return true;
        } 
        else if ( isThrowableNested() ) {
            return true;
        }

        Class cls = throwable.getClass();
        for (int i = 0, isize = CAUSE_METHOD_NAMES.length; i < isize; i++) {
            try {
                Method method = cls.getMethod(CAUSE_METHOD_NAMES[i], null);