software.amazon.awssdk.enhanced.dynamodb.model.PutItemEnhancedRequest Maven / Gradle / Ivy

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/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.enhanced.dynamodb.model;

import software.amazon.awssdk.annotations.SdkPublicApi;
import software.amazon.awssdk.enhanced.dynamodb.DynamoDbAsyncTable;
import software.amazon.awssdk.enhanced.dynamodb.DynamoDbTable;
import software.amazon.awssdk.enhanced.dynamodb.Expression;

/**
 * Defines parameters used to write an item to a DynamoDb table using the putItem() operation (such as
 * {@link DynamoDbTable#putItem(PutItemEnhancedRequest)} or {@link DynamoDbAsyncTable#putItem(PutItemEnhancedRequest)}).
 * 
 * A valid request object must contain the item that should be written to the table.
 * @param  The type of the modelled object.
 */
@SdkPublicApi
public final class PutItemEnhancedRequest {

    private final T item;
    private final Expression conditionExpression;

    private PutItemEnhancedRequest(Builder builder) {
        this.item = builder.item;
        this.conditionExpression = builder.conditionExpression;
    }

    /**
     * Creates a newly initialized builder for the request object.
     *
     * @param itemClass the class that items in this table map to
     * @param  The type of the modelled object, corresponding to itemClass
     * @return a PutItemEnhancedRequest builder
     */
    public static  Builder builder(Class itemClass) {
        return new Builder<>();
    }

    /**
     * Returns a builder initialized with all existing values on the request object.
     */
    public Builder toBuilder() {
        return new Builder().item(item).conditionExpression(conditionExpression);
    }

    /**
     * Returns the item for this put operation request.
     */
    public T item() {
        return item;
    }

    /**
     * Returns the condition {@link Expression} set on this request object, or null if it doesn't exist.
     */
    public Expression conditionExpression() {
        return conditionExpression;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        PutItemEnhancedRequest putItem = (PutItemEnhancedRequest) o;

        return item != null ? item.equals(putItem.item) : putItem.item == null;
    }

    @Override
    public int hashCode() {
        return item != null ? item.hashCode() : 0;
    }

    /**
     * A builder that is used to create a request with the desired parameters.
     * 

     * Note: A valid request builder must define an item.
     */
    public static final class Builder {
        private T item;
        private Expression conditionExpression;

        private Builder() {
        }

        /**
         * Sets the item to write to DynamoDb. Required.
         *
         * @param item the item to write
         * @return a builder of this type
         */
        public Builder item(T item) {
            this.item = item;
            return this;
        }

        /**
         * Defines a logical expression on an item's attribute values which, if evaluating to true,
         * will allow the put operation to succeed. If evaluating to false, the operation will not succeed.
         * 
         * See {@link Expression} for condition syntax and examples.
         *
         * @param conditionExpression a condition written as an {@link Expression}
         * @return a builder of this type
         */
        public Builder conditionExpression(Expression conditionExpression) {
            this.conditionExpression = conditionExpression;
            return this;
        }

        public PutItemEnhancedRequest build() {
            return new PutItemEnhancedRequest<>(this);
        }
    }
}