Java SQL Warning getRootCause(Throwable throwable)

Description

Walks through the exception chain to the last element -- the "root" of the tree -- using #getCause(Throwable) , and returns that exception.

License

Apache License

Parameter

Parameter	Description
throwable	the throwable to get the root cause for

Return

The root cause of the Throwable.

Declaration

public static Throwable getRootCause(Throwable throwable)

Method Source Code

//package com.java2s;
/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002-2003 The Apache Software Foundation.  All rights
 * reserved.//from w  w w . j a v a2 s  .c  o m
 *
 * 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.codehaus.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 codehaus@codehaus.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.codehaus.org/>.
 */

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.SQLException;

public class Main {
    /**
     * The names of methods commonly used to access a wrapped
     * exception.
     */
    protected static String[] CAUSE_METHOD_NAMES = { "getCause", "getNextException", "getTargetException",
            "getException", "getSourceException", "getRootCause", "getCausedByException", "getNested" };

    /**
     * <p>Walks through the exception chain to the last element -- the
     * "root" of the tree -- using {@link #getCause(Throwable)}, and
     * returns that exception.</p>
     *
     * @param throwable  the throwable to get the root cause for
     * @return The root cause of the <code>Throwable</code>.
     */
    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>Introspects the specified <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
     * The method names can be added to using {@link #addCauseMethodName(String)}.
     * The default list searched for are:</p>
     * <ul>
     * <li><code>getCause()</code>
     * <li><code>getNextException()</code>
     * <li><code>getTargetException()</code>
     * <li><code>getException()</code>
     * <li><code>getSourceException()</code>
     * <li><code>getRootCause()</code>
     * <li><code>getCausedByException()</code>
     * <li><code>getNested()</code>
     * </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 exception to introspect for a cause.
     * @return The cause of the <code>Throwable</code>.
     * @throws NullPointerException if the throwable is null
     */
    public static Throwable getCause(Throwable throwable) {
        return getCause(throwable, CAUSE_METHOD_NAMES);
    }

    /**
     * <p>Introspects the specified <code>Throwable</code> to obtain the cause
     * using a supplied array of method names.</p>
     *
     * @param throwable The exception to introspect for a cause.
     * @return The cause of the <code>Throwable</code>.
     * @throws NullPointerException if the method names array is null or contains null
     * @throws NullPointerException if the throwable is null
     */
    public static Throwable getCause(Throwable throwable, String[] methodNames) {
        Throwable cause = getCauseUsingWellKnownTypes(throwable);
        if (cause == null) {
            for (String methodName : methodNames) {
                cause = getCauseUsingMethodName(throwable, methodName);
                if (cause != null) {
                    break;
                }
            }

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

    /**
     * <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 SQLException) {
            return ((SQLException) throwable).getNextException();
        } else if (throwable instanceof InvocationTargetException) {
            return ((InvocationTargetException) throwable).getTargetException();
        } else {
            return null;
        }
    }

    /**
     * <p>Find a throwable 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, new Object[0]);
            } catch (IllegalAccessException ignored) {
            } catch (IllegalArgumentException ignored) {
            } catch (InvocationTargetException ignored) {
            }
        }
        return null;
    }

    /**
     * <p>Find a throwable 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;
    }
}

Java SQL Warning getRootCause(Throwable throwable)

Description

License

Parameter

Return

Declaration

Method Source Code

Related