Java DynamoDBQueryExpression.withHashKeyValues方法代码示例

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression; //导入方法依赖的package包/类
/**
 * Run Queries against dynamodb
 * @param clazz
 * @param itemKey
 * @param indexName
 * @param operator
 * @param rangeKeyConditions
 * @param limit
 * @param consistentRead
 * @return items
 */
public <T> List<T> query(final Class<T> clazz, final T itemKey, final String indexName, final ConditionalOperator operator,  final Map<String, Condition> rangeKeyConditions, final int limit, final boolean consistentRead){
	
	final DynamoDBQueryExpression<T> expression = new DynamoDBQueryExpression<T>();
	expression.withHashKeyValues(itemKey);
	expression.withConsistentRead(consistentRead);
	
	/**
	 * Optional Query parameters
	 */
	if(!Strings.isNullOrEmpty(indexName)){
		expression.withIndexName(indexName);
	}
	if(operator!=null){
		expression.withConditionalOperator(operator);
	}
	if(rangeKeyConditions != null && rangeKeyConditions.size()>0){
		expression.withRangeKeyConditions(rangeKeyConditions);
	}
	if(limit>0){
		expression.withLimit(limit);	
	}
	List<T> items = this.query(clazz, expression);
	if(items==null){
		return new ArrayList<T>();
	}else{
		return items;
	}
}
 

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression; //导入方法依赖的package包/类
/***
 * Get range keys for a given hashKey
 * @param clazz
 * @param itemHash
 * @return rangeKeys
 */
public <T> List<T> getRanges(final Class<T> clazz, final T itemHash, int limit, Map<String, AttributeValue> startKey){
	
	final Map<String, AttributeValue> starKey = Maps.newHashMap();
	final DynamoDBQueryExpression<T> query = new DynamoDBQueryExpression<T>();
	query.withHashKeyValues(itemHash);
	if(limit>0 && starKey!=null){
		query.withLimit(limit);
		query.withExclusiveStartKey(starKey);
	}
	return this.mapper.query(clazz, query);		
}
 

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression; //导入方法依赖的package包/类
@Override
public List<RecipeDraft> getDrafts(int userId) throws IOException {
    RecipeDraft recipeDraft = new RecipeDraft();
    recipeDraft.setUserId(userId);

    DynamoDBQueryExpression<RecipeDraft> queryExpression = new DynamoDBQueryExpression<>();
    queryExpression.withHashKeyValues(recipeDraft);
    return mapper.query(RecipeDraft.class, queryExpression);
}
 

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression; //导入方法依赖的package包/类
@Override
public int countDrafts(int userId) throws IOException {
    RecipeDraft recipeDraft = new RecipeDraft();
    recipeDraft.setUserId(userId);

    DynamoDBQueryExpression<RecipeDraft> queryExpression = new DynamoDBQueryExpression<>();
    queryExpression.withHashKeyValues(recipeDraft);
    return mapper.count(RecipeDraft.class, queryExpression);
}
 

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression; //导入方法依赖的package包/类
public DynamoDBQueryExpression<T> buildQueryExpression() {
	DynamoDBQueryExpression<T> queryExpression = new DynamoDBQueryExpression<T>();
	if (isHashKeySpecified()) {
		T hashKeyPrototype = entityInformation.getHashKeyPropotypeEntityForHashKey(getHashKeyPropertyValue());
		queryExpression.withHashKeyValues(hashKeyPrototype);
		queryExpression.withRangeKeyConditions(new HashMap<String, Condition>());
	}

	if (isRangeKeySpecified() && !isApplicableForGlobalSecondaryIndex()) {
		Condition rangeKeyCondition = createSingleValueCondition(getRangeKeyPropertyName(), ComparisonOperator.EQ,
				getRangeKeyAttributeValue(), getRangeKeyAttributeValue().getClass(), true);
		queryExpression.withRangeKeyCondition(getRangeKeyAttributeName(), rangeKeyCondition);
		applySortIfSpecified(queryExpression, Arrays.asList(new String[] { getRangeKeyPropertyName() }));

	} else if (isOnlyASingleAttributeConditionAndItIsOnEitherRangeOrIndexRangeKey()
			|| (isApplicableForGlobalSecondaryIndex())) {

		Entry<String, List<Condition>> singlePropertyConditions = propertyConditions.entrySet().iterator().next();

		List<String> allowedSortProperties = new ArrayList<String>();
		for (Entry<String, List<Condition>> singlePropertyCondition : propertyConditions.entrySet()) {
			if (entityInformation.getGlobalSecondaryIndexNamesByPropertyName().keySet()
					.contains(singlePropertyCondition.getKey())) {
				allowedSortProperties.add(singlePropertyCondition.getKey());
			}
		}
		if (allowedSortProperties.size() == 0) {
			allowedSortProperties.add(singlePropertyConditions.getKey());
		}

		for (Entry<String, List<Condition>> singleAttributeConditions : attributeConditions.entrySet()) {
			for (Condition condition : singleAttributeConditions.getValue()) {
				queryExpression.withRangeKeyCondition(singleAttributeConditions.getKey(), condition);
			}
		}

		applySortIfSpecified(queryExpression, allowedSortProperties);
		if (getGlobalSecondaryIndexName() != null) {
			queryExpression.setIndexName(getGlobalSecondaryIndexName());
		}
	} else {
		applySortIfSpecified(queryExpression, Arrays.asList(new String[] { getRangeKeyPropertyName() }));
	}

	return queryExpression;
}