org.springframework.integration.util.UUIDConverter.java Source code

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Here is the source code for org.springframework.integration.util.UUIDConverter.java

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/*
 * Copyright 2002-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.integration.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.UUID;

import org.springframework.core.convert.converter.Converter;
import org.springframework.util.ClassUtils;

/**
 * Utility to help generate UUID instances from generic objects.
 *
 * @author Dave Syer
 * @author Gary Russell
 */
public class UUIDConverter implements Converter<Object, UUID> {

    public static final String DEFAULT_CHARSET = "UTF-8";

    /**
     * Convert the input to a UUID using the convenience method
     * {@link #getUUID(Object)}.
     *
     * @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
     */
    @Override
    public UUID convert(Object source) {
        return getUUID(source);
    }

    /**
     * Convenient utility to convert an object to a UUID. If the input is
     * <ul>
     * <li>null: returns null</li>
     * <li>a UUID: returns the input unchanged</li>
     * <li>a String formatted as a UUID: returns the result of
     * {@link UUID#fromString(String)}</li>
     * <li>any other String: returns {@link UUID#nameUUIDFromBytes(byte[])} with
     * bytes generated from the input</li>
     * <li>a primitive or primitive wrapper: converts to a String ans then uses
     * the previous conversion method</li>
     * <li>Serializable: returns the {@link UUID#nameUUIDFromBytes(byte[])} with
     * the serialized bytes of the input</li>
     * </ul>
     * If none of the above applies there will be an exception trying to serialize.
     *
     * @param input an Object
     * @return a UUID constructed from the input
     */
    public static UUID getUUID(Object input) {
        if (input == null) {
            return null;
        }
        if (input instanceof UUID) {
            return (UUID) input;
        }
        if (input instanceof String) {
            try {
                return UUID.fromString((String) input);
            } catch (Exception e) {
                try {
                    return UUID.nameUUIDFromBytes(((String) input).getBytes(DEFAULT_CHARSET));
                } catch (UnsupportedEncodingException ex) {
                    IllegalStateException exception = new IllegalStateException(
                            "Cannot convert String using charset=" + DEFAULT_CHARSET, ex);
                    exception.addSuppressed(e);
                    throw exception; // NOSONAR - added to suppressed exceptions
                }
            }
        }
        if (ClassUtils.isPrimitiveOrWrapper(input.getClass())) {
            try {
                return UUID.nameUUIDFromBytes(input.toString().getBytes(DEFAULT_CHARSET));
            } catch (UnsupportedEncodingException e) {
                throw new IllegalStateException("Cannot convert primitive using charset=" + DEFAULT_CHARSET, e);
            }
        }
        byte[] bytes = serialize(input);
        return UUID.nameUUIDFromBytes(bytes);
    }

    private static byte[] serialize(Object object) {
        if (object == null) {
            return null;
        }
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        try {
            new ObjectOutputStream(stream).writeObject(object);
        } catch (IOException e) {
            throw new IllegalArgumentException("Could not serialize object of type: " + object.getClass(), e);
        }
        return stream.toByteArray();
    }

}