org.togglz.dynamodb.DynamoDBStateRepository Maven / Gradle / Ivy
Show all versions of togglz-dynamodb Show documentation
package org.togglz.dynamodb;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodbv2.document.DynamoDB;
import com.amazonaws.services.dynamodbv2.document.Item;
import com.amazonaws.services.dynamodbv2.document.Table;
import com.amazonaws.services.dynamodbv2.document.spec.GetItemSpec;
import com.amazonaws.services.dynamodbv2.model.ResourceNotFoundException;
import com.amazonaws.services.dynamodbv2.model.TableDescription;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.togglz.core.Feature;
import org.togglz.core.repository.FeatureState;
import org.togglz.core.repository.StateRepository;
import org.togglz.core.util.FeatureStateStorageWrapper;
import java.io.IOException;
/**
* A state repository that uses Amazon's DynamoDB.
*
* The repository is configured using the {@link DynamoDBStateRepositoryBuilder}
*
* You must already have a table provisioned before you create this repository.
*
* @author Ryan Gardner
* @date 8/26/16
*/
public class DynamoDBStateRepository implements StateRepository {
private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(DynamoDBStateRepository.class);
private ObjectMapper objectMapper = new ObjectMapper();
private Table table;
private String primaryKeyAttribute;
public static final String FEATURE_STATE_ATTRIBUTE_NAME = "featureState";
private AmazonDynamoDBClient amazonDynamoDBClient;
private DynamoDBStateRepository(DynamoDBStateRepositoryBuilder builder) {
this.objectMapper = builder.objectMapper;
this.table = builder.table;
this.primaryKeyAttribute = builder.primaryKey;
}
@Override
public FeatureState getFeatureState(Feature feature) {
Item documentItem = table.getItem(new GetItemSpec().withPrimaryKey(primaryKeyAttribute, feature.name()).withAttributesToGet(FEATURE_STATE_ATTRIBUTE_NAME));
if (documentItem != null) {
try {
FeatureStateStorageWrapper wrapper = objectMapper.reader().forType(FeatureStateStorageWrapper.class).readValue(documentItem.getJSON(FEATURE_STATE_ATTRIBUTE_NAME));
return FeatureStateStorageWrapper.featureStateForWrapper(feature, wrapper);
} catch (IOException e) {
throw new RuntimeException("Couldn't parse the feature state", e);
}
} else {
return null;
}
}
@Override
public void setFeatureState(FeatureState featureState) {
try {
String json = objectMapper.writeValueAsString(FeatureStateStorageWrapper.wrapperForFeatureState(featureState));
Item featureStateEntry =
new Item()
.withPrimaryKey(primaryKeyAttribute, featureState.getFeature().name())
.withJSON(FEATURE_STATE_ATTRIBUTE_NAME, json);
table.putItem(featureStateEntry);
} catch (JsonProcessingException e) {
throw new RuntimeException("Unable to serialize the feature state", e);
}
}
/**
*
* Builder for a DynamoDBStateRepository.
*
*
*
* Usage example:
*
*
*
* DynamoDBStateRepository dynamoDbStateRepository = new DynamoDBStateRepositoryBuilder(dbClient)
* .withStateStoredInTable("togglz-state-storage")
* .build();
*
*
* @author [email protected]
*/
public static class DynamoDBStateRepositoryBuilder {
public static final String DEFAULT_TABLE_NAME = "togglz";
private String tableName = DEFAULT_TABLE_NAME;
private AmazonDynamoDB amazonDynamoDBClient;
private ObjectMapper objectMapper;
private String primaryKey = "featureName";
private Table table;
private DynamoDB dynamoDB;
public DynamoDBStateRepositoryBuilder(AmazonDynamoDB dbClient) {
this.amazonDynamoDBClient = dbClient;
}
public DynamoDBStateRepositoryBuilder withObjectMapper(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
return this;
}
public DynamoDBStateRepositoryBuilder withStateStoredInTable(String tableName) {
this.tableName = tableName;
return this;
}
public DynamoDBStateRepository build() {
this.dynamoDB = new DynamoDB(this.amazonDynamoDBClient);
initializeObjectMapper();
initializeTable();
return new DynamoDBStateRepository(this);
}
private void initializeTable() {
this.table = dynamoDB.getTable(this.tableName);
if (table == null) {
throw new RuntimeException("Couldn't create a state repository using the table name provided");
} else {
try {
TableDescription tableDescription = table.describe();
log.info("Creating DynamoDBStateRepository with table named: {}", table.getTableName());
log.info("Table description: {}", tableDescription.toString());
} catch (ResourceNotFoundException e) {
if (tableName.equals(DEFAULT_TABLE_NAME)) {
log.error("The table with the default name '{}' could not be found. You must either create this table, or provide the name of an existing table to the builder to use as the state repository", DEFAULT_TABLE_NAME);
} else {
log.error("The table named '{}' can not be found. Please verify that the table is created in the region you are trying to run before using it to store the togglz state", tableName);
}
throw new RuntimeException("The table specified couldn't be found", e);
} catch (Exception e) {
log.error("Couldn't describe the table for an unknown reason. Please verify the table exists and you are able to access it", e);
throw new RuntimeException("Couldn't create a state repository using the supplied table", e);
}
}
}
// create a new object mapper if one wasn't passed into the builder
private void initializeObjectMapper() {
if (this.objectMapper == null) {
this.objectMapper = new ObjectMapper();
}
}
}
}