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The AWS SDK for Java with support for OSGi. The AWS SDK for Java provides Java APIs for building software on AWS' cost-effective, scalable, and reliable infrastructure products. The AWS Java SDK allows developers to code against APIs for all of Amazon's infrastructure web services (Amazon S3, Amazon EC2, Amazon SQS, Amazon Relational Database Service, Amazon AutoScaling, etc).
/*
* Copyright 2016-2016 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.
* You may obtain a copy of the License at:
*
* http://aws.amazon.com/apache2.0
*
* 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.datamodeling;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBDeleteExpression;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBSaveExpression;
import com.amazonaws.services.dynamodbv2.model.ConditionalCheckFailedException;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.ResourceInUseException;
import com.amazonaws.services.dynamodbv2.model.ResourceNotFoundException;
import com.amazonaws.services.dynamodbv2.model.TableDescription;
import com.amazonaws.services.s3.model.Region;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* A wrapper for {@code DynamoDBMapper} which operates only on a specified
* class/table. All calls are forwarded to the underlying
* {@code DynamoDBMapper} which was used to create this table mapper.
*
* A minimal example using get annotations,
*
* @DynamoDBTable(tableName="TestTable")
* public class TestClass {
* private Long key;
* private String rangeKey;
* private Double amount;
* private Long version;
*
* @DynamoDBHashKey
* public Long getKey() { return key; }
* public void setKey(Long key) { this.key = key; }
*
* @DynamoDBRangeKey
* public String getRangeKey() { return rangeKey; }
* public void setRangeKey(String rangeKey) { this.rangeKey = rangeKey; }
*
* @DynamoDBAttribute(attributeName="amount")
* public Double getAmount() { return amount; }
* public void setAmount(Double amount) { this.amount = amount; }
*
* @DynamoDBVersionAttribute
* public Long getVersion() { return version; }
* public void setVersion(Long version) { this.version = version; }
* }
*
*
* Initialize the DynamoDB mapper,
*
* AmazonDynamoDB dbClient = new AmazonDynamoDBClient();
* DynamoDBMapper dbMapper = new DynamoDBMapper(dbClient);
*
*
* Then, create a new table mapper with hash and range key,
*
* DynamoDBTableMapper<TestClass,Long,String> mapper = dbMapper.newTableMapper(TestClass.class);
*
*
* Or, if the table does not have a range key,
*
* DynamoDBTableMapper<TestClass,Long,?> mapper = dbMapper.newTableMapper(TestClass.class);
*
*
* If you don't have your DynamoDB table set up yet, you can use,
*
* mapper.createTableIfNotExists(new ProvisionedThroughput(25L, 25L));
*
*
* Save instances of annotated classes and retrieve them,
*
* TestClass object = new TestClass();
* object.setKey(1234L);
* object.setRangeKey("ABCD");
* object.setAmount(101D);
*
* try {
* mapper.saveIfNotExists(object);
* } catch (ConditionalCheckFailedException e) {
* // handle already existing
* }
*
*
* Execute a query operation,
*
* int limit = 10;
* List<TestClass> objects = new ArrayList<TestClass>(limit);
*
* DynamoDBQueryExpression<TestClass> query = mapper.queryExpressionOf(1234L)
* .withRangeKeyCondition(mapper..rangeKey().name(), mapper.rangeKey().ge("ABAA"))
* .withQueryFilterEntry("amount", mapper.field("amount").gt(100D))
* .withConsistentReads(true);
*
* QueryResultPage<TestClass> results = new QueryResultPage<TestClass>();
*
* do {
* if (results.getLastEvaluatedKey() != null) {
* query.setExclusiveStartKey(results.getLastEvaluatedKey());
* }
* query.setLimit(limit - objects.size());
* results = mapper.query(query);
* for (TestClass object : results.getResults()) {
* objects.add(object);
* }
* } while (results.getLastEvaluatedKey() != null && objects.size() < limit)
*
*
* @param The object type which this mapper operates.
* @param The hash key value type.
* @param The range key value type; use ? if no range key.
*
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper
* @see com.amazonaws.services.dynamodbv2.AmazonDynamoDB
*/
public final class DynamoDBTableMapper {
private static final Log LOG = LogFactory.getLog(DynamoDBTableMapper.class);
private final DynamoDBMapperTableModel model;
private final DynamoDBMapperFieldModel hk;
private final DynamoDBMapperFieldModel rk;
private final DynamoDBMapper mapper;
private final AmazonDynamoDB db;
/**
* Constructs a new table mapper for the given class.
* @param model The field model factory.
* @param mapper The DynamoDB mapper.
* @param db The service object to use for all service calls.
*/
protected DynamoDBTableMapper(final DynamoDBMapperTableModel model, final DynamoDBMapper mapper, final AmazonDynamoDB db) {
this.rk = model.rangeKeyIfExists();
this.hk = model.hashKey();
this.model = model;
this.mapper = mapper;
this.db = db;
}
/**
* Gets the field model for a given attribute.
* @param The field model's value type.
* @param attributeName The attribute name.
* @return The field model.
*/
public DynamoDBMapperFieldModel field(final String attributeName) {
return this.model.field(attributeName);
}
/**
* Gets the hash key field model for the specified type.
* @param The hash key type.
* @return The hash key field model.
* @throws DynamoDBMappingException If the hash key is not present.
*/
public DynamoDBMapperFieldModel hashKey() {
return this.model.hashKey();
}
/**
* Gets the range key field model for the specified type.
* @param The range key type.
* @return The range key field model.
* @throws DynamoDBMappingException If the range key is not present.
*/
public DynamoDBMapperFieldModel rangeKey() {
return this.model.rangeKey();
}
/**
* Retrieves multiple items from the table using their primary keys.
* @param itemsToGet The items to get.
* @return The list of objects.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#batchLoad
*/
public final List batchLoad(final Iterable itemsToGet) {
final Map> results = mapper.batchLoad(itemsToGet);
return results.isEmpty() ? Collections.emptyList() : (List)results.get(model.tableName());
}
/**
* Saves the objects given using one or more calls to the batchWriteItem API.
* @param objectsToSave The objects to save.
* @return The list of failed batches.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#batchSave
*/
public final List batchSave(final Iterable objectsToSave) {
return mapper.batchWrite(objectsToSave, (Iterable)Collections.emptyList());
}
/**
* Deletes the objects given using one or more calls to the batchWtiteItem API.
* @param objectsToDelete The objects to delete.
* @return The list of failed batches.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#batchDelete
*/
public final List batchDelete(final Iterable objectsToDelete) {
return mapper.batchWrite((Iterable)Collections.emptyList(), objectsToDelete);
}
/**
* Saves and deletes the objects given using one or more calls to the
* batchWriteItem API.
* @param objectsToWrite The objects to write.
* @param objectsToDelete The objects to delete.
* @return The list of failed batches.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#batchWrite
*/
public final List batchWrite(final Iterable objectsToWrite, final Iterable objectsToDelete) {
return mapper.batchWrite(objectsToWrite, objectsToDelete);
}
/**
* Loads an object with the hash key given.
* @param hashKey The hash key value.
* @return The object.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#load
*/
public final T load(final H hashKey) {
return mapper.load(model.targetType(), hashKey);
}
/**
* Loads an object with the hash and range key.
* @param hashKey The hash key value.
* @param rangeKey The range key value.
* @return The object.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#load
*/
public final T load(final H hashKey, final R rangeKey) {
return mapper.load(model.targetType(), hashKey, rangeKey);
}
/**
* Saves the object given into DynamoDB.
* @param object The object to save.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#save
*/
public final void save(final T object) {
mapper.save(object);
}
/**
* Saves the object given into DynamoDB using the specified saveExpression.
* @param object The object to save.
* @param saveExpression The save expression.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#save
*/
public final void save(final T object, final DynamoDBSaveExpression saveExpression) {
mapper.save(object, saveExpression);
}
/**
* Saves the object given into DynamoDB with the condition that the hash
* and if applicable, the range key, does not already exist.
* @param object The object to create.
* @throws ConditionalCheckFailedException If the object exists.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#save
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBSaveExpression
* @see com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue
*/
public final void saveIfNotExists(final T object) throws ConditionalCheckFailedException {
final DynamoDBSaveExpression saveExpression = new DynamoDBSaveExpression();
saveExpression.withExpectedEntry(hk.name(), hk.expectedNotExists());
if (rk != null) {
saveExpression.withExpectedEntry(rk.name(), rk.expectedNotExists());
}
mapper.save(object, saveExpression);
}
/**
* Saves the object given into DynamoDB with the condition that the hash
* and, if applicable, the range key, already exist.
* @param object The object to update.
* @throws ConditionalCheckFailedException If the object does not exist.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#save
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBSaveExpression
* @see com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue
*/
public final void saveIfExists(final T object) throws ConditionalCheckFailedException {
final DynamoDBSaveExpression saveExpression = new DynamoDBSaveExpression();
saveExpression.withExpectedEntry(hk.name(), hk.expectedExists(hk.get(object)));
if (rk != null) {
saveExpression.withExpectedEntry(rk.name(), rk.expectedExists(rk.get(object)));
}
mapper.save(object, saveExpression);
}
/**
* Deletes the given object from its DynamoDB table.
* @param object The object to delete.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#delete
*/
public final void delete(final T object) {
mapper.delete(object);
}
/**
* Deletes the given object from its DynamoDB table using the specified
* deleteExpression.
* @param object The object to delete.
* @param deleteExpression The delete expression.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#delete
*/
public final void delete(final T object, final DynamoDBDeleteExpression deleteExpression) {
mapper.delete(object, deleteExpression);
}
/**
* Deletes the given object from its DynamoDB table with the condition that
* the hash and, if applicable, the range key, already exist.
* @param object The object to delete.
* @throws ConditionalCheckFailedException If the object does not exist.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#delete
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBDeleteExpression
* @see com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue
*/
public final void deleteIfExists(final T object) throws ConditionalCheckFailedException {
final DynamoDBDeleteExpression deleteExpression = new DynamoDBDeleteExpression();
deleteExpression.withExpectedEntry(hk.name(), hk.expectedExists(hk.get(object)));
if (rk != null) {
deleteExpression.withExpectedEntry(rk.name(), rk.expectedExists(rk.get(object)));
}
mapper.delete(object, deleteExpression);
}
/**
* Evaluates the specified query expression and returns the count of matching
* items, without returning any of the actual item data
* @param queryExpression The query expression.
* @return The count.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#count
*/
public final int count(final DynamoDBQueryExpression queryExpression) {
return mapper.count(model.targetType(), queryExpression);
}
/**
* Queries an Amazon DynamoDB table and returns the matching results as an
* unmodifiable list of instantiated objects.
* @param queryExpression The query expression.
* @return The query results.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#query
*/
public final QueryResultPage query(final DynamoDBQueryExpression queryExpression) {
return mapper.queryPage(model.targetType(), queryExpression);
}
/**
* Queries an Amazon DynamoDB table and returns a single page of matching
* results.
* @param queryExpression The query expression.
* @return The query results.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#query
*/
public final QueryResultPage queryPage(final DynamoDBQueryExpression queryExpression) {
return mapper.queryPage(model.targetType(), queryExpression);
}
/**
* Evaluates the specified scan expression and returns the count of matching
* items, without returning any of the actual item data.
* @param scanExpression The scan expression.
* @return The count.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#count
*/
public final int count(final DynamoDBScanExpression scanExpression) {
return mapper.count(model.targetType(), scanExpression);
}
/**
* Scans through an Amazon DynamoDB table and returns the matching results
* as an unmodifiable list of instantiated objects.
* @param scanExpression The scan expression.
* @return The scan results.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#scan
*/
public final PaginatedScanList scan(final DynamoDBScanExpression scanExpression) {
return mapper.scan(model.targetType(), scanExpression);
}
/**
* Scans through an Amazon DynamoDB table and returns a single page of
* matching results.
* @param scanExpression The scan expression.
* @return The scan results.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#scanPage
*/
public final ScanResultPage scanPage(final DynamoDBScanExpression scanExpression) {
return mapper.scanPage(model.targetType(), scanExpression);
}
/**
* Scans through an Amazon DynamoDB table on logically partitioned segments
* in parallel and returns the matching results in one unmodifiable list of
* instantiated objects.
* @param scanExpression The scan expression.
* @param totalSegments The total segments.
* @return The scan results.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#parallelScan
*/
public final PaginatedParallelScanList parallelScan(final DynamoDBScanExpression scanExpression, int totalSegments) {
return mapper.parallelScan(model.targetType(), scanExpression, totalSegments);
}
/**
* Creates an S3Link with the specified region, bucket name and key.
* @param s3region The S3 region.
* @param bucketName The bucket name.
* @param key The key.
* @return The created S3Link.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#createS3Link
*/
public final S3Link createS3Link(final Region s3region, final String bucketName, final String key) {
return mapper.createS3Link(s3region, bucketName, key);
}
/**
* Creates an S3Link with the specified bucket name and key using the
* default S3 region.
* @param bucketName The bucket name.
* @param key The key.
* @return The created S3Link.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#createS3Link
*/
public final S3Link createS3Link(final String bucketName, final String key) {
return mapper.createS3Link(bucketName, key);
}
/**
* Returns the underlying S3ClientCache for accessing S3.
* @return The underlying S3ClientCache.
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#getS3ClientCache
*/
public final S3ClientCache getS3ClientCache() {
return mapper.getS3ClientCache();
}
/**
* Returns information about the table, including the current status of the
* table, when it was created, the primary key schema, and any indexes on
* the table.
* @return The describe table results.
* @see com.amazonaws.services.dynamodbv2.AmazonDynamoDB#describeTable
*/
public final TableDescription describeTable() {
return db.describeTable(model.tableName()).getTable();
}
/**
* Creates the table and ignores the {@code ResourceInUseException} if it
* ialready exists.
* @param throughput The provisioned throughput.
* @return True if created, or false if the table already existed.
* @see com.amazonaws.services.dynamodbv2.AmazonDynamoDB#createTable
* @see com.amazonaws.services.dynamodbv2.model.CreateTableRequest
*/
public final boolean createTableIfNotExists(final ProvisionedThroughput throughput) {
try {
db.createTable(mapper.generateCreateTableRequest(model.targetType()).withProvisionedThroughput(throughput));
} catch (final ResourceInUseException e) {
if (LOG.isTraceEnabled()) {
LOG.trace("Table " + model.tableName() + " already exists, no need to create", e);
}
return false;
}
return true;
}
/**
* Deletes the table and ignores the {@code ResourceNotFoundException} if
* it does not already exist.
* @return True if the table was deleted, or false if the table did not exist.
* @see com.amazonaws.services.dynamodbv2.AmazonDynamoDB#deleteTable
* @see com.amazonaws.services.dynamodbv2.model.DeleteTableRequest
*/
public final boolean deleteTableIfExists() {
try {
db.deleteTable(mapper.generateDeleteTableRequest(model.targetType()));
} catch (final ResourceNotFoundException e) {
if (LOG.isTraceEnabled()) {
LOG.trace("Table " + model.tableName() + " does not exist, no need to delete", e);
}
return false;
}
return true;
}
}
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