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Commons IO example source code file (TaggedIOException.java)

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

Java - Commons IO tags/keywords

io, ioexception, ioexception, ioexceptionwithcause, object, object, override, serializable, serializable, taggedioexception, taggedioexception

The Commons IO TaggedIOException.java 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.io;

import java.io.IOException;
import java.io.Serializable;

/**
 * An {@link IOException} decorator that adds a serializable tag to the
 * wrapped exception. Both the tag and the original exception can be used
 * to determine further processing when this exception is caught.
 *
 * @since Commons IO 2.0
 */
public class TaggedIOException extends IOExceptionWithCause {

    /**
     * Generated serial version UID.
     */
    private static final long serialVersionUID = -6994123481142850163L;

    /**
     * Checks whether the given throwable is tagged with the given tag.
     * <p>
     * This check can only succeed if the throwable is a
     * {@link TaggedIOException} and the tag is {@link Serializable}, but
     * the argument types are intentionally more generic to make it easier
     * to use this method without type casts.
     * <p>
     * A typical use for this method is in a <code>catch block to
     * determine how a caught exception should be handled:
     * <pre>
     * Serializable tag = ...;
     * try {
     *     ...;
     * } catch (Throwable t) {
     *     if (TaggedIOExcepton.isTaggedWith(t, tag)) {
     *         // special processing for tagged exception
     *     } else {
     *         // handling of other kinds of exceptions
     *     }
     * }
     * </pre>
     *
     * @param throwable The Throwable object to check
     * @param tag tag object
     * @return <code>true if the throwable has the specified tag,
     * otherwise <code>false
     */
    public static boolean isTaggedWith(Throwable throwable, Object tag) {
        return tag != null
            && throwable instanceof TaggedIOException
            && tag.equals(((TaggedIOException) throwable).tag);
    }

    /**
     * Throws the original {@link IOException} if the given throwable is
     * a {@link TaggedIOException} decorator the given tag. Does nothing
     * if the given throwable is of a different type or if it is tagged
     * with some other tag.
     * <p>
     * This method is typically used in a <code>catch block to
     * selectively rethrow tagged exceptions.
     * <pre>
     * Serializable tag = ...;
     * try {
     *     ...;
     * } catch (Throwable t) {
     *     TaggedIOExcepton.throwCauseIfTagged(t, tag);
     *     // handle other kinds of exceptions
     * }
     * </pre>
     *
     * @param throwable an exception
     * @param tag tag object
     * @throws IOException original exception from the tagged decorator, if any
     */
    public static void throwCauseIfTaggedWith(Throwable throwable, Object tag)
            throws IOException {
        if (isTaggedWith(throwable, tag)) {
            throw ((TaggedIOException) throwable).getCause();
        }
    }

    /**
     * The tag of this exception.
     */
    private final Serializable tag;

    /**
     * Creates a tagged wrapper for the given exception.
     *
     * @param original the exception to be tagged
     * @param tag tag of this exception
     */
    public TaggedIOException(IOException original, Serializable tag) {
        super(original.getMessage(), original);
        this.tag = tag;
    }

    /**
     * Returns the serializable tag object.
     *
     * @return tag object
     */
    public Serializable getTag() {
        return tag;
    }

    /**
     * Returns the wrapped exception. The only difference to the overridden
     * {@link Throwable#getCause()} method is the narrower return type.
     *
     * @return wrapped exception
     */
    @Override
    public IOException getCause() {
        return (IOException) super.getCause();
    }

}

Other Commons IO examples (source code examples)

Here is a short list of links related to this Commons IO TaggedIOException.java source code file:



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