public class DynamoDBMapper extends AbstractDynamoDBMapper
To use, define a domain class that represents an item in a DynamoDB table and annotate it with the annotations found in the com.amazonaws.services.dynamodbv2.datamodeling package. In order to allow the mapper to correctly persist the data, each modeled property in the domain class should be accessible via getter and setter methods, and each property annotation should be either applied to the getter method or the class field. A minimal example using getter annotations:
@DynamoDBTable(tableName = "TestTable") public class TestClass { private Long key; private double rangeKey; private Long version; private Set<Integer> integerSetAttribute; @DynamoDBHashKey public Long getKey() { return key; } public void setKey(Long key) { this.key = key; } @DynamoDBRangeKey public double getRangeKey() { return rangeKey; } public void setRangeKey(double rangeKey) { this.rangeKey = rangeKey; } @DynamoDBAttribute(attributeName = "integerSetAttribute") public Set<Integer> getIntegerAttribute() { return integerSetAttribute; } public void setIntegerAttribute(Set<Integer> integerAttribute) { this.integerSetAttribute = integerAttribute; } @DynamoDBVersionAttribute public Long getVersion() { return version; } public void setVersion(Long version) { this.version = version; } }
Save instances of annotated classes to DynamoDB, retrieve them, and delete
them using the DynamoDBMapper
class, as in the following example.
DynamoDBMapper mapper = new DynamoDBMapper(dynamoDBClient); Long hashKey = 105L; double rangeKey = 1.0d; TestClass obj = mapper.load(TestClass.class, hashKey, rangeKey); obj.getIntegerAttribute().add(42); mapper.save(obj); mapper.delete(obj);
If you don't have your DynamoDB table set up yet, you can use
AbstractDynamoDBMapper.generateCreateTableRequest(Class)
to construct the
CreateTableRequest
for the table represented by your annotated class.
AmazonDynamoDB dynamoDBClient = new AmazonDynamoDBClient(); DynamoDBMapper mapper = new DynamoDBMapper(dynamoDBClient); CreateTableRequest req = mapper.generateCreateTableRequest(TestClass.class); // Table provision throughput is still required since it cannot be specified in your POJO req.setProvisionedThroughput(new ProvisionedThroughput(5L, 5L)); // Fire off the CreateTableRequest using the low-level client dynamoDBClient.createTable(req);
When using the save, load, and delete methods, DynamoDBMapper
will
throw DynamoDBMappingException
s to indicate that domain classes are
incorrectly annotated or otherwise incompatible with this class. Service
exceptions will always be propagated as SdkClientException
, and
DynamoDB-specific subclasses such as ConditionalCheckFailedException
will be used when possible.
This class is thread-safe and can be shared between threads. It's also very lightweight, so it doesn't need to be.
Modifier and Type | Class and Description |
---|---|
static class |
DynamoDBMapper.BatchGetItemException |
static class |
DynamoDBMapper.FailedBatch
The return type of batchWrite, batchDelete and batchSave.
|
protected class |
DynamoDBMapper.SaveObjectHandler
The handler for saving object using DynamoDBMapper.
|
Constructor and Description |
---|
DynamoDBMapper(AmazonDynamoDB dynamoDB)
Constructs a new mapper with the service object given, using the default
configuration.
|
DynamoDBMapper(AmazonDynamoDB ddb,
AWSCredentialsProvider s3CredentialProvider)
Constructs a new mapper with the service object and S3 client cache
given, using the default configuration.
|
DynamoDBMapper(AmazonDynamoDB dynamoDB,
DynamoDBMapperConfig config)
Constructs a new mapper with the service object and configuration given.
|
DynamoDBMapper(AmazonDynamoDB dynamoDB,
DynamoDBMapperConfig config,
AttributeTransformer transformer)
Constructs a new mapper with the given service object, configuration,
and transform hook.
|
DynamoDBMapper(AmazonDynamoDB dynamoDB,
DynamoDBMapperConfig config,
AttributeTransformer transformer,
AWSCredentialsProvider s3CredentialsProvider)
Constructor with all parameters.
|
DynamoDBMapper(AmazonDynamoDB dynamoDB,
DynamoDBMapperConfig config,
AWSCredentialsProvider s3CredentialProvider)
Constructs a new mapper with the service object, configuration, and S3
client cache given.
|
Modifier and Type | Method and Description |
---|---|
Map<String,List<Object>> |
batchLoad(Iterable<? extends Object> itemsToGet,
DynamoDBMapperConfig config)
Retrieves multiple items from multiple tables using their primary keys.
|
Map<String,List<Object>> |
batchLoad(Map<Class<?>,List<KeyPair>> itemsToGet,
DynamoDBMapperConfig config)
Retrieves multiple items from multiple tables using their primary keys.
|
List<DynamoDBMapper.FailedBatch> |
batchWrite(Iterable<? extends Object> objectsToWrite,
Iterable<? extends Object> objectsToDelete,
DynamoDBMapperConfig config)
Saves and deletes the objects given using one or more calls to the
AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest) API. |
int |
count(Class<?> clazz,
DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config)
Evaluates the specified scan expression and returns the count of matching items, without
returning any of the actual item data.
|
<T> int |
count(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression,
DynamoDBMapperConfig config)
Evaluates the specified query expression and returns the count of matching items, without
returning any of the actual item data.
|
S3Link |
createS3Link(Region s3region,
String bucketName,
String key)
Creates an S3Link with the specified region, bucket name and key.
|
S3Link |
createS3Link(String s3region,
String bucketName,
String key)
Creates an S3Link with the specified region, bucket name and key.
|
<T> void |
delete(T object,
DynamoDBDeleteExpression deleteExpression,
DynamoDBMapperConfig config)
Deletes the given object from its DynamoDB table using the provided deleteExpression and
provided configuration.
|
<T> CreateTableRequest |
generateCreateTableRequest(Class<T> clazz,
DynamoDBMapperConfig config) |
<T> DeleteTableRequest |
generateDeleteTableRequest(Class<T> clazz,
DynamoDBMapperConfig config) |
S3ClientCache |
getS3ClientCache()
Returns the underlying
S3ClientCache for accessing S3. |
<T> DynamoDBMapperTableModel<T> |
getTableModel(Class<T> clazz,
DynamoDBMapperConfig config)
Get the table model for the class using the provided configuration override.
|
<T> T |
load(Class<T> clazz,
Object hashKey,
Object rangeKey,
DynamoDBMapperConfig config)
Returns an object with the given hash key, or null if no such object exists.
|
<T> T |
load(T keyObject,
DynamoDBMapperConfig config)
Returns an object whose keys match those of the prototype key object given, or null if no
such item exists.
|
<T> T |
marshallIntoObject(Class<T> clazz,
Map<String,AttributeValue> itemAttributes,
DynamoDBMapperConfig config) |
<T> List<T> |
marshallIntoObjects(Class<T> clazz,
List<Map<String,AttributeValue>> itemAttributes,
DynamoDBMapperConfig config) |
<T,H,R> DynamoDBTableMapper<T,H,R> |
newTableMapper(Class<T> clazz)
Creates a new table mapper using this mapper to perform operations.
|
<T> PaginatedParallelScanList<T> |
parallelScan(Class<T> clazz,
DynamoDBScanExpression scanExpression,
int totalSegments,
DynamoDBMapperConfig config)
Scans through an Amazon DynamoDB table on logically partitioned segments in parallel.
|
<T> PaginatedQueryList<T> |
query(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression,
DynamoDBMapperConfig config)
Queries an Amazon DynamoDB table and returns the matching results as an unmodifiable list of
instantiated objects.
|
<T> QueryResultPage<T> |
queryPage(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression,
DynamoDBMapperConfig config)
Queries an Amazon DynamoDB table and returns a single page of matching results.
|
<T> void |
save(T object,
DynamoDBSaveExpression saveExpression,
DynamoDBMapperConfig config)
Saves an item in DynamoDB.
|
<T> PaginatedScanList<T> |
scan(Class<T> clazz,
DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config)
Scans through an Amazon DynamoDB table and returns the matching results as an unmodifiable
list of instantiated objects.
|
<T> ScanResultPage<T> |
scanPage(Class<T> clazz,
DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config)
Scans through an Amazon DynamoDB table and returns a single page of matching results.
|
batchDelete, batchDelete, batchLoad, batchLoad, batchSave, batchSave, batchWrite, count, count, createS3Link, delete, delete, delete, generateCreateTableRequest, generateDeleteTableRequest, getTableModel, getTableName, getTableName, load, load, load, load, marshallIntoObject, marshallIntoObjects, mergeConfig, parallelScan, query, queryPage, save, save, save, scan, scanPage
public DynamoDBMapper(AmazonDynamoDB dynamoDB)
dynamoDB
- The service object to use for all service calls.DynamoDBMapperConfig.DEFAULT
public DynamoDBMapper(AmazonDynamoDB dynamoDB, DynamoDBMapperConfig config)
dynamoDB
- The service object to use for all service calls.config
- The default configuration to use for all service calls. It can
be overridden on a per-operation basis.public DynamoDBMapper(AmazonDynamoDB ddb, AWSCredentialsProvider s3CredentialProvider)
ddb
- The service object to use for all service calls.s3CredentialProvider
- The credentials provider for accessing S3.
Relevant only if S3Link
is involved.DynamoDBMapperConfig.DEFAULT
public DynamoDBMapper(AmazonDynamoDB dynamoDB, DynamoDBMapperConfig config, AttributeTransformer transformer)
dynamoDB
- the service object to use for all service callsconfig
- the default configuration to use for all service calls. It
can be overridden on a per-operation basistransformer
- The custom attribute transformer to invoke when serializing or
deserializing an object.public DynamoDBMapper(AmazonDynamoDB dynamoDB, DynamoDBMapperConfig config, AWSCredentialsProvider s3CredentialProvider)
dynamoDB
- The service object to use for all service calls.config
- The default configuration to use for all service calls. It can
be overridden on a per-operation basis.s3CredentialProvider
- The credentials provider for accessing S3.
Relevant only if S3Link
is involved.public DynamoDBMapper(AmazonDynamoDB dynamoDB, DynamoDBMapperConfig config, AttributeTransformer transformer, AWSCredentialsProvider s3CredentialsProvider)
dynamoDB
- The service object to use for all service calls.config
- The default configuration to use for all service calls. It can
be overridden on a per-operation basis.transformer
- The custom attribute transformer to invoke when serializing or
deserializing an object.s3CredentialProvider
- The credentials provider for accessing S3.
Relevant only if S3Link
is involved.public <T> DynamoDBMapperTableModel<T> getTableModel(Class<T> clazz, DynamoDBMapperConfig config)
IDynamoDBMapper
getTableModel
in interface IDynamoDBMapper
getTableModel
in class AbstractDynamoDBMapper
public <T> T load(T keyObject, DynamoDBMapperConfig config)
IDynamoDBMapper
load
in interface IDynamoDBMapper
load
in class AbstractDynamoDBMapper
keyObject
- An object of the class to load with the keys values to match.config
- Configuration for the service call to retrieve the object from DynamoDB. This
configuration overrides the default given at construction.public <T> T load(Class<T> clazz, Object hashKey, Object rangeKey, DynamoDBMapperConfig config)
IDynamoDBMapper
load
in interface IDynamoDBMapper
load
in class AbstractDynamoDBMapper
clazz
- The class to load, corresponding to a DynamoDB table.hashKey
- The key of the object.rangeKey
- The range key of the object, or null for tables without a range key.config
- Configuration for the service call to retrieve the object from DynamoDB. This
configuration overrides the default given at construction.public <T> T marshallIntoObject(Class<T> clazz, Map<String,AttributeValue> itemAttributes, DynamoDBMapperConfig config)
marshallIntoObject
in class AbstractDynamoDBMapper
public <T> List<T> marshallIntoObjects(Class<T> clazz, List<Map<String,AttributeValue>> itemAttributes, DynamoDBMapperConfig config)
marshallIntoObjects
in class AbstractDynamoDBMapper
public <T> void save(T object, DynamoDBSaveExpression saveExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
DynamoDBMapperConfig.getSaveBehavior()
value, to use either
AmazonDynamoDB.putItem(PutItemRequest)
or
AmazonDynamoDB.updateItem(UpdateItemRequest)
:
save
in interface IDynamoDBMapper
save
in class AbstractDynamoDBMapper
object
- The object to save into DynamoDBsaveExpression
- The options to apply to this save requestconfig
- The configuration to use, which overrides the default provided at object
construction.DynamoDBMapperConfig.SaveBehavior
public <T> void delete(T object, DynamoDBDeleteExpression deleteExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
delete
in interface IDynamoDBMapper
delete
in class AbstractDynamoDBMapper
deleteExpression
- The options to apply to this delete requestconfig
- Config override object. If DynamoDBMapperConfig.SaveBehavior.CLOBBER
is supplied, version
fields will not be considered when deleting the object.public List<DynamoDBMapper.FailedBatch> batchWrite(Iterable<? extends Object> objectsToWrite, Iterable<? extends Object> objectsToDelete, DynamoDBMapperConfig config)
IDynamoDBMapper
AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest)
API. Use mapper config to
control the retry strategy when UnprocessedItems are returned by the BatchWriteItem API
This method fails to save the batch if the size of an individual object in the batch exceeds 400 KB. For more information on batch restrictions see, http://docs.aws.amazon .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html
If one of the write requests is for a table that is not present, this method does not throw a ResourceNotFoundException but returns a FailedBatch which includes this exception and the unprocessed items.
batchWrite
in interface IDynamoDBMapper
batchWrite
in class AbstractDynamoDBMapper
objectsToWrite
- A list of objects to save to DynamoDB. No version checks are performed, as
required by the AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest)
API.objectsToDelete
- A list of objects to delete from DynamoDB. No version checks are performed,
as required by the AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest)
API.config
- Only DynamoDBMapperConfig.getTableNameOverride()
and
DynamoDBMapperConfig.getBatchWriteRetryStrategy()
are considered. If
TableNameOverride is specified, all objects in the two parameter lists will be
considered to belong to the given table override. In particular, this method
always acts as if SaveBehavior.CLOBBER was specified regardless of the
value of the config parameter.DynamoDBMapperConfig.getTableNameOverride()
,
DynamoDBMapperConfig.getBatchWriteRetryStrategy()
public Map<String,List<Object>> batchLoad(Iterable<? extends Object> itemsToGet, DynamoDBMapperConfig config)
IDynamoDBMapper
batchLoad
in interface IDynamoDBMapper
batchLoad
in class AbstractDynamoDBMapper
itemsToGet
- Key objects, corresponding to the class to fetch, with their primary key values
set.config
- Only DynamoDBMapperConfig.getTableNameOverride()
and
DynamoDBMapperConfig.getConsistentReads()
are considered.public Map<String,List<Object>> batchLoad(Map<Class<?>,List<KeyPair>> itemsToGet, DynamoDBMapperConfig config)
IDynamoDBMapper
DynamoDBMapper#batchLoad(List, DynamoDBMapperConfig)
batchLoad
in interface IDynamoDBMapper
batchLoad
in class AbstractDynamoDBMapper
itemsToGet
- Map from class to load to list of primary key attributes.config
- Only DynamoDBMapperConfig.getTableNameOverride()
and
DynamoDBMapperConfig.getConsistentReads()
are considered.public <T> PaginatedScanList<T> scan(Class<T> clazz, DynamoDBScanExpression scanExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
Callers should be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.
You can specify the pagination loading strategy for this scan operation. By default, the list returned is lazily loaded when possible.
scan
in interface IDynamoDBMapper
scan
in class AbstractDynamoDBMapper
T
- The type of the objects being returned.clazz
- The class annotated with DynamoDB annotations describing how to store the object
data in Amazon DynamoDB.scanExpression
- Details on how to run the scan, including any filters to apply to limit results.config
- The configuration to use for this scan, which overrides the default provided at
object construction.PaginatedScanList
,
DynamoDBMapperConfig.PaginationLoadingStrategy
public <T> PaginatedParallelScanList<T> parallelScan(Class<T> clazz, DynamoDBScanExpression scanExpression, int totalSegments, DynamoDBMapperConfig config)
IDynamoDBMapper
Callers should be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.
You can specify the pagination loading strategy for this parallel scan operation. By default, the list returned is lazily loaded when possible.
parallelScan
in interface IDynamoDBMapper
parallelScan
in class AbstractDynamoDBMapper
T
- The type of the objects being returned.clazz
- The class annotated with DynamoDB annotations describing how to store the object
data in Amazon DynamoDB.scanExpression
- Details on how to run the scan, including any filters to apply to limit results.totalSegments
- Number of total parallel scan segments. Range: 1 - 4096config
- The configuration to use for this scan, which overrides the default provided at
object construction.PaginatedParallelScanList
,
DynamoDBMapperConfig.PaginationLoadingStrategy
public <T> ScanResultPage<T> scanPage(Class<T> clazz, DynamoDBScanExpression scanExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
scanPage
in interface IDynamoDBMapper
scanPage
in class AbstractDynamoDBMapper
T
- The type of the objects being returned.clazz
- The class annotated with DynamoDB annotations describing how to store the object
data in Amazon DynamoDB.scanExpression
- Details on how to run the scan, including any filters to apply to limit results.config
- The configuration to use for this scan, which overrides the default provided at
object construction.public <T> PaginatedQueryList<T> query(Class<T> clazz, DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
When the query is on any local/global secondary index, callers should be aware that the returned object(s) will only contain item attributes that are projected into the index. All the other unprojected attributes will be saved as type default values.
Callers should also be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.
You can specify the pagination loading strategy for this query operation. By default, the list returned is lazily loaded when possible.
query
in interface IDynamoDBMapper
query
in class AbstractDynamoDBMapper
T
- The type of the objects being returned.clazz
- The class annotated with DynamoDB annotations describing how to store the object
data in Amazon DynamoDB.queryExpression
- Details on how to run the query, including any conditions on the key valuesconfig
- The configuration to use for this query, which overrides the default provided at
object construction.PaginatedQueryList
,
DynamoDBMapperConfig.PaginationLoadingStrategy
public <T> QueryResultPage<T> queryPage(Class<T> clazz, DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
queryPage
in interface IDynamoDBMapper
queryPage
in class AbstractDynamoDBMapper
T
- The type of the objects being returned.clazz
- The class annotated with DynamoDB annotations describing how to store the object
data in AWS DynamoDB.queryExpression
- Details on how to run the query, including any conditions on the key valuesconfig
- The configuration to use for this query, which overrides the default provided at
object construction.public int count(Class<?> clazz, DynamoDBScanExpression scanExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
This operation will scan your entire table, and can therefore be very expensive. Use with caution.
count
in interface IDynamoDBMapper
count
in class AbstractDynamoDBMapper
clazz
- The class mapped to a DynamoDB table.scanExpression
- The parameters for running the scan.config
- The configuration to use for this scan, which overrides the default provided at
object construction.public <T> int count(Class<T> clazz, DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config)
IDynamoDBMapper
count
in interface IDynamoDBMapper
count
in class AbstractDynamoDBMapper
clazz
- The class mapped to a DynamoDB table.queryExpression
- The parameters for running the scan.config
- The mapper configuration to use for the query, which overrides the default
provided at object construction.public S3ClientCache getS3ClientCache()
IDynamoDBMapper
S3ClientCache
for accessing S3.getS3ClientCache
in interface IDynamoDBMapper
getS3ClientCache
in class AbstractDynamoDBMapper
public S3Link createS3Link(Region s3region, String bucketName, String key)
IDynamoDBMapper
createS3Link
in interface IDynamoDBMapper
createS3Link
in class AbstractDynamoDBMapper
public S3Link createS3Link(String s3region, String bucketName, String key)
IDynamoDBMapper
createS3Link
in interface IDynamoDBMapper
createS3Link
in class AbstractDynamoDBMapper
public <T> CreateTableRequest generateCreateTableRequest(Class<T> clazz, DynamoDBMapperConfig config)
generateCreateTableRequest
in class AbstractDynamoDBMapper
public <T> DeleteTableRequest generateDeleteTableRequest(Class<T> clazz, DynamoDBMapperConfig config)
generateDeleteTableRequest
in class AbstractDynamoDBMapper
public <T,H,R> DynamoDBTableMapper<T,H,R> newTableMapper(Class<T> clazz)
T
- The object type which this mapper operates.H
- The hash key value type.R
- The range key value type; use ?
if no range key.clazz
- The object class.Copyright © 2017. All rights reserved.