Module com.erudika.para.server

Package com.erudika.para.server.persistence

Class AWSDynamoUtils

java.lang.Object

com.erudika.para.server.persistence.AWSDynamoUtils

public final class AWSDynamoUtils
extends Object

Helper utilities for connecting to AWS DynamoDB.

Author:

Alex Bogdanovski [[email protected]]

Method Summary

Modifier and Type	Method	Description
static boolean	createSharedTable(long readCapacity, long writeCapacity)	Creates a table in AWS DynamoDB which will be shared between apps.
static boolean	createTable(String appid)	Creates a DynamoDB table.
static boolean	createTable(String appid, int maxReadCapacity, int maxWriteCapacity)	Creates a table in AWS DynamoDB.
static void	deleteAllFromSharedTable(String appid)	Deletes all objects in a shared table, which belong to a given appid, by scanning the GSI.
static boolean	deleteTable(String appid)	Deletes the main table from AWS DynamoDB.
static boolean	existsTable(String appid)	Checks if the main table exists in the database.
static software.amazon.awssdk.services.dynamodb.DynamoDbClient	getClient()	Returns a client instance for AWS DynamoDB.
static String	getKeyForAppid(String key, String appIdentifier)	Returns the correct key for an object given the appid (table name).
static List<String>	getReplicaRegions()	Returns the list of regions where a table should be replicated (global table).
static software.amazon.awssdk.services.dynamodb.model.GlobalSecondaryIndexDescription	getSharedGlobalIndex()	Returns the Index object for the shared table.
static String	getTableNameForAppid(String appIdentifier)	Returns the table name for a given app id.
static Map<String,Object>	getTableStatus(String appid)	Gives basic information about a DynamoDB table (status, creation date, size).
static boolean	isSharedAppid(String appIdentifier)	Returns true if appid starts with a space " ".
static List<String>	listAllTables()	Lists all table names for this account.
static <P extends com.erudika.para.core.ParaObject> List<P>	readPageFromSharedTable(String appid, com.erudika.para.core.utils.Pager pager)	Reads a page from a "shared" DynamoDB table.
static <P extends com.erudika.para.core.ParaObject> List<P>	readPageFromTable(String appid, com.erudika.para.core.utils.Pager p)	Reads a page from a standard DynamoDB table.
static boolean	updateTable(String appid, long readCapacity, long writeCapacity)	Updates the table settings (read and write capacities).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

getClient

public static software.amazon.awssdk.services.dynamodb.DynamoDbClient getClient()

Returns a client instance for AWS DynamoDB.

Returns:

a client that talks to DynamoDB

existsTable

public static boolean existsTable(String appid)

Checks if the main table exists in the database.

Parameters:

appid - name of the App

Returns:

true if the table exists

createTable

public static boolean createTable(String appid)

Creates a DynamoDB table.

Parameters:

appid - name of the App

Returns:

true if created

createTable

public static boolean createTable(String appid,
 int maxReadCapacity,
 int maxWriteCapacity)

Creates a table in AWS DynamoDB.

Parameters:

appid - name of the App

maxReadCapacity - max read capacity for autoscaling (only applicable in PROVISIONED billing mode)

maxWriteCapacity - max write capacity for autoscaling (only applicable in PROVISIONED billing mode)

Returns:

true if created

updateTable

public static boolean updateTable(String appid,
 long readCapacity,
 long writeCapacity)

Updates the table settings (read and write capacities).

Parameters:

appid - name of the App

readCapacity - read capacity

writeCapacity - write capacity

Returns:

true if updated

deleteTable

public static boolean deleteTable(String appid)

Deletes the main table from AWS DynamoDB.

Parameters:

appid - name of the App

Returns:

true if deleted

createSharedTable

public static boolean createSharedTable(long readCapacity,
 long writeCapacity)

Creates a table in AWS DynamoDB which will be shared between apps.

Parameters:

readCapacity - read capacity

writeCapacity - write capacity

Returns:

true if created

getTableStatus

public static Map<String,Object> getTableStatus(String appid)

Gives basic information about a DynamoDB table (status, creation date, size).

Parameters:

appid - name of the App

Returns:

a map

listAllTables

public static List<String> listAllTables()

Lists all table names for this account.

Returns:

a list of DynamoDB tables

getTableNameForAppid

public static String getTableNameForAppid(String appIdentifier)

Returns the table name for a given app id. Table names are usually in the form 'prefix-appid'.

Parameters:

appIdentifier - app id

Returns:

the table name

getKeyForAppid

public static String getKeyForAppid(String key,
 String appIdentifier)

Returns the correct key for an object given the appid (table name).

Parameters:

key - a row id

appIdentifier - appid

Returns:

the key

readPageFromTable

public static <P extends com.erudika.para.core.ParaObject>
List<P> readPageFromTable(String appid,
 com.erudika.para.core.utils.Pager p)

Reads a page from a standard DynamoDB table.

Type Parameters:

P - type of object

Parameters:

appid - the app identifier (name)

p - a Pager

Returns:

the last row key of the page, or null.

readPageFromSharedTable

public static <P extends com.erudika.para.core.ParaObject>
List<P> readPageFromSharedTable(String appid,
 com.erudika.para.core.utils.Pager pager)

Reads a page from a "shared" DynamoDB table. Shared tables are tables that have global secondary indexes and can contain the objects of multiple apps.

Type Parameters:

P - type of object

Parameters:

appid - the app identifier (name)

pager - a Pager

Returns:

the id of the last object on the page, or null.

deleteAllFromSharedTable

public static void deleteAllFromSharedTable(String appid)

Deletes all objects in a shared table, which belong to a given appid, by scanning the GSI.

Parameters:

appid - app id

getSharedGlobalIndex

public static software.amazon.awssdk.services.dynamodb.model.GlobalSecondaryIndexDescription getSharedGlobalIndex()

Returns the Index object for the shared table.

Returns:

the Index object or null

isSharedAppid

public static boolean isSharedAppid(String appIdentifier)

Returns true if appid starts with a space " ".

Parameters:

appIdentifier - appid

Returns:

true if appid starts with " "

getReplicaRegions

public static List<String> getReplicaRegions()

Returns the list of regions where a table should be replicated (global table).

Returns:

a list of regions