org.springframework.data.rest.webmvc.json.patch.MoveOperation.java Source code

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Here is the source code for org.springframework.data.rest.webmvc.json.patch.MoveOperation.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.data.rest.webmvc.json.patch;

import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;

import org.springframework.data.rest.webmvc.json.patch.SpelPath.UntypedSpelPath;

/**
 * <p>
 * Operation that moves a value from the given "from" path to the given "path". Will throw a {@link PatchException} if
 * either path is invalid or if the from path is non-nullable.
 * </p>
 * <p>
 * NOTE: When dealing with lists, the move operation may effectively be a no-op. That's because the order of a list is
 * probably dictated by a database query that produced the list. Moving things around in the list will have no bearing
 * on the values of each item in the list. When the same list resource is retrieved again later, the order will again be
 * decided by the query, effectively undoing any previous move operation.
 * </p>
 *
 * @author Craig Walls
 * @author Oliver Gierke
 */
class MoveOperation extends PatchOperation {

    private final UntypedSpelPath from;

    /**
     * Constructs the move operation.
     *
     * @param path The path to move the source value to. (e.g., '/foo/bar/4')
     * @param from The source path from which a value will be moved. (e.g., '/foo/bar/5')
     */
    private MoveOperation(UntypedSpelPath path, UntypedSpelPath from) {

        super("move", path);

        this.from = from;
    }

    static MoveOperationBuilder from(String from) {
        return new MoveOperationBuilder(from);
    }

    @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
    static class MoveOperationBuilder {

        private final String from;

        public MoveOperation to(String to) {
            return new MoveOperation(SpelPath.untyped(to), SpelPath.untyped(from));
        }
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.rest.webmvc.json.patch.PatchOperation#perform(java.lang.Object, java.lang.Class)
     */
    @Override
    void perform(Object target, Class<?> type) {
        path.bindTo(type).moveFrom(from, target);
    }
}