GetItemImpl.java

/*
 * Copyright 2014-2017 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 com.amazonaws.services.dynamodbv2.document.internal;

import java.util.Map;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.document.GetItemOutcome;
import com.amazonaws.services.dynamodbv2.document.Item;
import com.amazonaws.services.dynamodbv2.document.KeyAttribute;
import com.amazonaws.services.dynamodbv2.document.PrimaryKey;
import com.amazonaws.services.dynamodbv2.document.Table;
import com.amazonaws.services.dynamodbv2.document.api.GetItemApi;
import com.amazonaws.services.dynamodbv2.document.spec.GetItemSpec;
import com.amazonaws.services.dynamodbv2.model.GetItemRequest;
import com.amazonaws.services.dynamodbv2.model.GetItemResult;

/**
 * The implementation for <code>GetItemApi</code>.
 */
public class GetItemImpl extends AbstractImpl implements GetItemApi {
    public GetItemImpl(AmazonDynamoDB client, Table table) {
        super(client, table);
    }

    @Override
    public GetItemOutcome getItemOutcome(KeyAttribute... primaryKeyComponents) {
        return doLoadItem(new GetItemSpec()
                   .withPrimaryKey(primaryKeyComponents));
    }

    @Override
    public GetItemOutcome getItemOutcome(PrimaryKey primaryKey) {
        return doLoadItem(new GetItemSpec()
        .withPrimaryKey(primaryKey));
    }

    @Override
    public GetItemOutcome getItemOutcome(PrimaryKey primaryKey,
            String projectionExpression, Map<String, String> nameMap) {
        return doLoadItem(new GetItemSpec()
                .withPrimaryKey(primaryKey)
                .withProjectionExpression(projectionExpression)
                .withNameMap(nameMap));
    }

    @Override
    public GetItemOutcome getItemOutcome(GetItemSpec spec) {
        return doLoadItem(spec);
    }

    @Override
    public Item getItem(GetItemSpec spec) {
        return doLoadItem(spec).getItem();
    }

    private GetItemOutcome doLoadItem(GetItemSpec spec) {
        String tableName = getTable().getTableName();
        // Set up the key attributes
        GetItemRequest req = spec.getRequest()
                .withTableName(tableName)
                .withKey(InternalUtils.toAttributeValueMap(spec.getKeyComponents()))
                .withExpressionAttributeNames(spec.getNameMap());

        GetItemResult result = getClient().getItem(req);
        return new GetItemOutcome(result);
    }

    @Override
    public Item getItem(KeyAttribute... primaryKey) {
        return getItemOutcome(primaryKey).getItem();
    }

    @Override
    public Item getItem(PrimaryKey primaryKey) {
        return getItemOutcome(primaryKey).getItem();
    }

    @Override
    public Item getItem(PrimaryKey primaryKey, String projectionExpression,
            Map<String, String> nameMap) {
        return getItemOutcome(primaryKey, projectionExpression, nameMap).getItem();
    }

    @Override
    public GetItemOutcome getItemOutcome(String hashKeyName, Object hashKeyValue) {
        return getItemOutcome(new KeyAttribute(hashKeyName, hashKeyValue));
    }

    @Override
    public GetItemOutcome getItemOutcome(String hashKeyName, Object hashKeyValue,
            String rangeKeyName, Object rangeKeyValue) {
        return getItemOutcome(new KeyAttribute(hashKeyName, hashKeyValue),
                new KeyAttribute(rangeKeyName, rangeKeyValue));
    }

    @Override
    public Item getItem(String hashKeyName, Object hashKeyValue) {
        return getItemOutcome(hashKeyName, hashKeyValue).getItem();
    }

    @Override
    public Item getItem(String hashKeyName, Object hashKeyValue,
            String rangeKeyName, Object rangeKeyValue) {
        return getItemOutcome(hashKeyName, hashKeyValue, rangeKeyName, rangeKeyValue).getItem();
    }

    @Override
    public GetItemOutcome getItemOutcome(String hashKeyName, Object hashKeyValue,
            String projectionExpression, Map<String, String> nameMap) {
        return getItemOutcome(new PrimaryKey(hashKeyName, hashKeyValue),
                projectionExpression, nameMap);
    }

    @Override
    public GetItemOutcome getItemOutcome(String hashKeyName, Object hashKeyValue,
            String rangeKeyName, Object rangeKeyValue,
            String projectionExpression, Map<String, String> nameMap) {
        return getItemOutcome(
            new PrimaryKey(hashKeyName, hashKeyValue, rangeKeyName, rangeKeyValue),
                projectionExpression, nameMap);
    }

    @Override
    public Item getItem(String hashKeyName, Object hashKeyValue,
            String projectionExpression, Map<String, String> nameMap) {
        return getItemOutcome(new PrimaryKey(hashKeyName, hashKeyValue),
                projectionExpression, nameMap).getItem();
    }

    @Override
    public Item getItem(String hashKeyName, Object hashKeyValue,
            String rangeKeyName, Object rangeKeyValue,
            String projectionExpression, Map<String, String> nameMap) {
        return getItemOutcome(
            new PrimaryKey(hashKeyName, hashKeyValue, rangeKeyName, rangeKeyValue),
            projectionExpression, nameMap).getItem();
    }
}