org.apache.hadoop.service.ServiceStateException.java Source code

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Here is the source code for org.apache.hadoop.service.ServiceStateException.java

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/*
 * 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.hadoop.service;

import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.service.launcher.LauncherExitCodes;
import org.apache.hadoop.util.ExitCodeProvider;

/**
 * Exception that can be raised on state change operations, whose
 * exit code can be explicitly set, determined from that of any nested
 * cause, or a default value of
 * {@link  LauncherExitCodes#EXIT_SERVICE_LIFECYCLE_EXCEPTION}.
 */
@Public
@Evolving
public class ServiceStateException extends RuntimeException implements ExitCodeProvider {

    private static final long serialVersionUID = 1110000352259232646L;

    /**
     * Exit code.
     */
    private int exitCode;

    /**
     * Instantiate
     * @param message error message
     */
    public ServiceStateException(String message) {
        this(message, null);
    }

    /**
     * Instantiate with a message and cause; if the cause has an exit code
     * then it is used, otherwise the generic
     * {@link LauncherExitCodes#EXIT_SERVICE_LIFECYCLE_EXCEPTION} exit code
     * is used.
     * @param message exception message
     * @param cause optional inner cause
     */
    public ServiceStateException(String message, Throwable cause) {
        super(message, cause);
        if (cause instanceof ExitCodeProvider) {
            this.exitCode = ((ExitCodeProvider) cause).getExitCode();
        } else {
            this.exitCode = LauncherExitCodes.EXIT_SERVICE_LIFECYCLE_EXCEPTION;
        }
    }

    /**
     * Instantiate, using the specified exit code as the exit code
     * of the exception, irrespetive of any exit code supplied by any inner
     * cause.
     *
     * @param exitCode exit code to declare
     * @param message exception message
     * @param cause inner cause
     */
    public ServiceStateException(int exitCode, String message, Throwable cause) {
        this(message, cause);
        this.exitCode = exitCode;
    }

    public ServiceStateException(Throwable cause) {
        super(cause);
    }

    @Override
    public int getExitCode() {
        return exitCode;
    }

    /**
     * Convert any exception into a {@link RuntimeException}.
     * All other exception types are wrapped in a new instance of
     * {@code ServiceStateException}.
     * @param fault exception or throwable
     * @return a {@link RuntimeException} to rethrow
     */
    public static RuntimeException convert(Throwable fault) {
        if (fault instanceof RuntimeException) {
            return (RuntimeException) fault;
        } else {
            return new ServiceStateException(fault);
        }
    }

    /**
     * Convert any exception into a {@link RuntimeException}.
     * If the caught exception is already of that type, it is typecast to a
     * {@link RuntimeException} and returned.
     *
     * All other exception types are wrapped in a new instance of
     * {@code ServiceStateException}.
     * @param text text to use if a new exception is created
     * @param fault exception or throwable
     * @return a {@link RuntimeException} to rethrow
     */
    public static RuntimeException convert(String text, Throwable fault) {
        if (fault instanceof RuntimeException) {
            return (RuntimeException) fault;
        } else {
            return new ServiceStateException(text, fault);
        }
    }
}