org.aracrown.commons.util.Exceptions.java Source code

Introduction

Here is the source code for org.aracrown.commons.util.Exceptions.java

Source

/*
 * Copyright 2013 ARA Crown
 *
 * Licensed 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.aracrown.commons.util;

import com.google.common.base.Throwables;
import com.google.common.collect.Iterables;

/**
 * Static utility methods for handling exceptions.
 *
 * @author vicento.ramos
 * @since 1.0.0
 */
public final class Exceptions {
    /**
     * The singleton instance.
     */
    private static Exceptions instance;

    private Exceptions() {
    }

    /**
     * The static getter of singleton instance.
     *
     * @return static instance of <i>Exceptions</i>
     */
    public static Exceptions get() {
        if (instance == null) {
            instance = new Exceptions();
        }
        return instance;
    }

    /**
     * Checks {@code throwable} for a cause of type {@code class1}. Throws new exception if found.
     *
     * @param throwable         exception to check for cause type
     * @param class1            cause type to check
     * @param replacedThrowable new custom exception to throw if cause type was found
     * @param <X>               exception type to search for
     * @param <Y>               exception type to be re-thrown
     * @throws Y exception thrown if cause type was found in chain
     */
    public <X extends Throwable, Y extends Throwable> void throwNewIfContains(Throwable throwable, Class<X> class1,
            Y replacedThrowable) throws Y {
        Iterable<X> i = Iterables.filter(Throwables.getCausalChain(throwable), class1);
        // Do not expect null here.
        if (i.iterator().hasNext()) {
            throw replacedThrowable;
        }
    }

    /**
     * Checks {@code throwable} for a cause of type {@code class1}. Throws cause exception if found.
     *
     * @param throwable exception to check for cause type
     * @param class1    cause type to check
     * @param <X>       exception type to be re-thrown
     * @throws X exception thrown if cause type was found in chain
     */
    public <X extends Throwable> void propagate(Throwable throwable, Class<X> class1) throws X {
        Iterable<X> i = Iterables.filter(Throwables.getCausalChain(throwable), class1);
        // Do not expect null here.
        if (i.iterator().hasNext()) {
            throw i.iterator().next();
        }
    }
}