org.springframework.amqp.core.MessageBuilder.java Source code

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Here is the source code for org.springframework.amqp.core.MessageBuilder.java

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/*
 * Copyright 2014-2019 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.amqp.core;

import java.util.Arrays;

import org.springframework.util.Assert;

/**
 * Builds a Spring AMQP Message either from a byte[] body or
 * another Message using a fluent API.
 *
 * @author Gary Russell
 * @since 1.3
 *
 */
public final class MessageBuilder extends MessageBuilderSupport<Message> {

    private static final String MESSAGE_CANNOT_BE_NULL = "'message' cannot be null";

    private static final String BODY_CANNOT_BE_NULL = "'body' cannot be null";

    private final byte[] body;

    /**
     * The final message body will be a direct reference to 'body'.
     * @param body The body.
     * @return The builder.
     */
    public static MessageBuilder withBody(byte[] body) {
        Assert.notNull(body, BODY_CANNOT_BE_NULL);
        return new MessageBuilder(body);
    }

    /**
     * The final message body will be a copy of 'body' in a new array.
     * @param body The body.
     * @return The builder.
     */
    public static MessageBuilder withClonedBody(byte[] body) {
        Assert.notNull(body, BODY_CANNOT_BE_NULL);
        return new MessageBuilder(Arrays.copyOf(body, body.length));
    }

    /**
     * The final message body will be a new array containing the byte range from
     * 'body'.
     * @param body The body.
     * @param from The starting index.
     * @param to The ending index.
     * @return The builder.
     *
     * @see Arrays#copyOfRange(byte[], int, int)
     */
    public static MessageBuilder withBody(byte[] body, int from, int to) {
        Assert.notNull(body, BODY_CANNOT_BE_NULL);
        return new MessageBuilder(Arrays.copyOfRange(body, from, to));
    }

    /**
     * The final message body will be a direct reference to the message
     * body, the MessageProperties will be a shallow copy.
     * @param message The message.
     * @return The builder.
     */
    public static MessageBuilder fromMessage(Message message) {
        Assert.notNull(message, MESSAGE_CANNOT_BE_NULL);
        return new MessageBuilder(message);
    }

    /**
     * The final message will have a copy of the message
     * body, the MessageProperties will be cloned (top level only).
     * @param message The message.
     * @return The builder.
     */
    public static MessageBuilder fromClonedMessage(Message message) {
        Assert.notNull(message, MESSAGE_CANNOT_BE_NULL);
        byte[] body = message.getBody();
        Assert.notNull(body, BODY_CANNOT_BE_NULL);
        return new MessageBuilder(Arrays.copyOf(body, body.length), message.getMessageProperties());
    }

    private MessageBuilder(byte[] body) { //NOSONAR
        this.body = body;
    }

    private MessageBuilder(Message message) {
        this(message.getBody(), message.getMessageProperties());
    }

    private MessageBuilder(byte[] body, MessageProperties properties) { //NOSONAR
        this.body = body;
        this.copyProperties(properties);
    }

    /**
     * Makes this builder's properties builder use a reference to properties.
     * @param properties The properties.
     * @return this.
     */
    public MessageBuilder andProperties(MessageProperties properties) {
        this.setProperties(properties);
        return this;
    }

    @Override
    public Message build() {
        return new Message(this.body, this.buildProperties());
    }

}