Java tutorial
/** * Copyright 2013 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. A copy of the License is located at * * http://aws.amazon.com/apache2.0/ * * or in the "LICENSE" file accompanying this file. 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 awslabs.lab22; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import com.amazonaws.AmazonServiceException; import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient; import com.amazonaws.services.dynamodbv2.model.AttributeDefinition; import com.amazonaws.services.dynamodbv2.model.AttributeValue; import com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate; import com.amazonaws.services.dynamodbv2.model.Condition; import com.amazonaws.services.dynamodbv2.model.CreateTableRequest; import com.amazonaws.services.dynamodbv2.model.DeleteTableRequest; import com.amazonaws.services.dynamodbv2.model.DescribeTableRequest; import com.amazonaws.services.dynamodbv2.model.DescribeTableResult; import com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue; import com.amazonaws.services.dynamodbv2.model.KeySchemaElement; import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput; import com.amazonaws.services.dynamodbv2.model.PutItemRequest; import com.amazonaws.services.dynamodbv2.model.QueryRequest; import com.amazonaws.services.dynamodbv2.model.QueryResult; import com.amazonaws.services.dynamodbv2.model.TableDescription; import com.amazonaws.services.dynamodbv2.model.UpdateItemRequest; /** * Project: Lab2.2 */ public abstract class SolutionCode implements ILabCode, IOptionalLabCode { @Override public void createAccountItem(AmazonDynamoDBClient ddbClient, String tableName, Account account) { // Create a HashMap<String, AttributeValue> object to hold the attributes of the item to add. Map<String, AttributeValue> itemAttributes = new HashMap<String, AttributeValue>(); // Add the required items (Company and Email) from the account parameter to the attribute HashMap. itemAttributes.put("Company", new AttributeValue().withS(account.getCompany())); itemAttributes.put("Email", new AttributeValue().withS(account.getEmail())); // Check the account parameter and add all values that aren't empty strings ("") to the attribute HashMap. if (!account.getFirst().equals("")) { itemAttributes.put("First", new AttributeValue().withS(account.getFirst())); } if (!account.getLast().equals("")) { itemAttributes.put("Last", new AttributeValue().withS(account.getLast())); } if (!account.getAge().equals("")) { itemAttributes.put("Age", new AttributeValue().withN(account.getAge())); } // Construct a PutItemRequest object to put the attributes into the specified table. PutItemRequest putItemRequest = new PutItemRequest().withTableName(tableName).withItem(itemAttributes); // Submit the request using the putItem method of the ddbClient object. ddbClient.putItem(putItemRequest); } @Override public QueryResult lookupByHashKey(AmazonDynamoDBClient ddbClient, String tableName, String company) { // Construct an AttributeValue object containing the provided company name. AttributeValue attributeValue = new AttributeValue().withS(company); // Construct a Condition object containing the desired comparison ("EQ") and the attribute value // containing the company name. Condition condition = new Condition().withComparisonOperator("EQ").withAttributeValueList(attributeValue); // Construct a QueryRequest object that performs a consistent read on the specified table for the // previously constructed condition. QueryRequest queryRequest = new QueryRequest().withTableName(tableName).withConsistentRead(true); queryRequest.addKeyConditionsEntry("Company", condition); // Submit the query by calling the query method of the ddbClient object and return the result. return ddbClient.query(queryRequest); } @Override public void updateIfMatch(AmazonDynamoDBClient ddbClient, String tableName, String email, String company, String firstNameTarget, String firstNameMatch) { // Construct an UpdateItemRequest object for the specified table. UpdateItemRequest updateItemRequest = new UpdateItemRequest().withTableName(tableName); // Add KeyEntry elements to the request containing AttributeValue objects for the company name and email // address provided. updateItemRequest.addKeyEntry("Company", new AttributeValue().withS(company)); updateItemRequest.addKeyEntry("Email", new AttributeValue().withS(email)); // Add an ExpectedEntry element to the request containing an ExpectedAttributeValue object that contains // the value in the firstNameMatch parameter. updateItemRequest.addExpectedEntry("First", new ExpectedAttributeValue().withValue(new AttributeValue().withS(firstNameMatch))); // Add an AttributeUpdatesEntry element to the request containing an AttributeValueUpdate object that // contains the value in the firstNameTarget parameter updateItemRequest.addAttributeUpdatesEntry("First", new AttributeValueUpdate().withAction("PUT") .withValue(new AttributeValue().withS(firstNameTarget))); // Submit the request using the updateItem method of the ddbClient object. ddbClient.updateItem(updateItemRequest); } @Override public void deleteTable(AmazonDynamoDBClient ddbClient, String tableName) { String tableStatus = getTableStatus(ddbClient, tableName); if (tableStatus.equals("ACTIVE")) { System.out.println("Deleting pre-existing table."); DeleteTableRequest deleteTableRequest = new DeleteTableRequest().withTableName(tableName); ddbClient.deleteTable(deleteTableRequest); waitForStatus(ddbClient, tableName, "NOTFOUND"); System.out.println("Table deletion confirmed."); } else if (tableStatus.equals("NOTFOUND")) { System.out.println("Skipped deletion operation. Table not found."); } else { System.out.println("Skipped deletion operation. Table not in correct state."); } } @Override public void buildTable(AmazonDynamoDBClient ddbClient, String tableName) { System.out.println("Creating table."); CreateTableRequest createTableRequest = new CreateTableRequest().withTableName(tableName); createTableRequest.setAttributeDefinitions(new ArrayList<AttributeDefinition>()); // Define attributes createTableRequest.getAttributeDefinitions() .add(new AttributeDefinition().withAttributeName("Company").withAttributeType("S")); createTableRequest.getAttributeDefinitions() .add(new AttributeDefinition().withAttributeName("Email").withAttributeType("S")); // Define key schema createTableRequest.setKeySchema(new ArrayList<KeySchemaElement>()); createTableRequest.getKeySchema() .add(new KeySchemaElement().withAttributeName("Company").withKeyType("HASH")); createTableRequest.getKeySchema() .add(new KeySchemaElement().withAttributeName("Email").withKeyType("RANGE")); // Define provisioned throughput createTableRequest.setProvisionedThroughput( new ProvisionedThroughput().withReadCapacityUnits(10L).withWriteCapacityUnits(5L)); // Submit create request ddbClient.createTable(createTableRequest); // Pause until the table is active waitForStatus(ddbClient, tableName, "ACTIVE"); System.out.println("Table created and active."); } @Override public String getTableStatus(AmazonDynamoDBClient ddbClient, String tableName) { TableDescription tableDescription = getTableDescription(ddbClient, tableName); if (tableDescription == null) { return "NOTFOUND"; } return tableDescription.getTableStatus(); } @Override public TableDescription getTableDescription(AmazonDynamoDBClient ddbClient, String tableName) { try { DescribeTableRequest describeTableRequest = new DescribeTableRequest().withTableName(tableName); DescribeTableResult describeTableResult = ddbClient.describeTable(describeTableRequest); return describeTableResult.getTable(); } catch (AmazonServiceException ase) { // If the table isn't found, there's no problem. // If the error is something else, re-throw the exception to bubble it up to the caller. if (!ase.getErrorCode().equals("ResourceNotFoundException")) { throw ase; } return null; } } @Override public void waitForStatus(AmazonDynamoDBClient ddbClient, String tableName, String status) { while (!getTableStatus(ddbClient, tableName).equals(status)) { // Sleep for one second. try { Thread.sleep(1000); } catch (InterruptedException e) { // Just gobble up the exception. } } } }