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.List; import java.util.Map; import java.util.Map.Entry; import awslabs.labutility.LabUtility; import com.amazonaws.auth.ClasspathPropertiesFileCredentialsProvider; import com.amazonaws.regions.Region; import com.amazonaws.regions.Regions; 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.KeySchemaElement; import com.amazonaws.services.dynamodbv2.model.QueryResult; import com.amazonaws.services.dynamodbv2.model.TableDescription; /** * Project: Lab2.2 */ public class Lab22 { private static Region region = Region.getRegion(Regions.US_EAST_1); // BEGIN NON-STUDENT_CODE private static ILabCode labCode = new StudentCode(); private static IOptionalLabCode optionalLabCode = new StudentCode(); private static String tableName = "Accounts"; /** * Controls the flow of the lab code execution. */ public static void main(String[] args) { try { // Create DynamoDB client and set the region to US East (Virginia) AmazonDynamoDBClient ddbClient = new AmazonDynamoDBClient( new ClasspathPropertiesFileCredentialsProvider()); ddbClient.setRegion(region); List<Account> accounts = new ArrayList<Account>(); accounts.add(new Account().withCompany("Amazon.com").withEmail("johndoe@amazon.com").withFirst("John") .withLast("Doe").withAge("33")); accounts.add(new Account().withCompany("Asperatus Tech").withEmail("janedoe@amazon.com") .withFirst("Jane").withLast("Doe").withAge("24")); accounts.add(new Account().withCompany("Amazon.com").withEmail("jimjohnson@amazon.com").withFirst("Jim") .withLast("Johnson")); // Verify that the table schema is as we expect, and correct any // problems we find. if (!confirmTableSchema(ddbClient, tableName)) { System.out.print("Deleting. "); optionalLabCode.deleteTable(ddbClient, tableName); System.out.print("Rebuilding. "); optionalLabCode.buildTable(ddbClient, tableName); System.out.println("Done."); } System.out.println("Adding items to table."); // Create the accounts for (Account account : accounts) { labCode.createAccountItem(ddbClient, tableName, account); System.out.println("Added item: " + account.getCompany() + "/" + account.getEmail()); } System.out.println("Requesting matches for Company == Amazon.com"); QueryResult queryResult = labCode.lookupByHashKey(ddbClient, tableName, "Amazon.com"); if (queryResult != null && queryResult.getCount() > 0) { // Record was found for (Map<String, AttributeValue> item : queryResult.getItems()) { System.out.println("Item Found-"); for (Entry<String, AttributeValue> attribute : item.entrySet()) { System.out.print(" " + attribute.getKey() + ":"); if (attribute.getKey().equals("Age")) { System.out.println(attribute.getValue().getN()); } else { System.out.println(attribute.getValue().getS()); } } } } else { System.out.println("No matches found."); } // Conditionally update a record System.out.print("Attempting update. "); labCode.updateIfMatch(ddbClient, tableName, "jimjohnson@amazon.com", "Amazon.com", "James", "Jim"); System.out.println("Done."); } catch (Exception ex) { LabUtility.dumpError(ex); } } /** * Validate the table matches the expected schema for the lab. Since it's built by hand, there's a decent chance * that it may not be what's expected. * * @param ddbClient The DynamoDB client object. * @param tableName The name of the table to validate. * * @return True if the schema of the table is correct. False if a problem is found. */ private static Boolean confirmTableSchema(AmazonDynamoDBClient ddbClient, String tableName) { System.out.println("Confirming table schema."); TableDescription tableDescription = optionalLabCode.getTableDescription(ddbClient, tableName); if (tableDescription == null) { System.out.println("Table does not exist."); // Can't match the schema if the table isn't there. return false; } if (!tableDescription.getTableStatus().equals("ACTIVE")) { System.out.println("Table is not active."); return false; } if (tableDescription.getAttributeDefinitions() == null || tableDescription.getKeySchema() == null) { System.out.println("Schema doesn't match."); return false; } for (AttributeDefinition attributeDefinition : tableDescription.getAttributeDefinitions()) { String attributeName = attributeDefinition.getAttributeName(); if (attributeName.equals("Company") || attributeName.equals("Email") || attributeName.equals("First") || attributeName.equals("Last")) { if (!attributeDefinition.getAttributeType().equals("S")) { // We have a matching attribute, but the type is wrong. System.out.println(attributeDefinition.getAttributeName() + " attribute is wrong type in attribute definition."); return false; } } else if (attributeName.equals("Age")) { if (!attributeDefinition.getAttributeType().equals("N")) { System.out.println("Age attribute is wrong type in attribute definition."); // We have a matching attribute, but the type is wrong. return false; } } } // If we've gotten here, the attributes are good. Now check the key // schema. if (tableDescription.getKeySchema().size() != 2) { System.out.println("Wrong number of elements in the key schema."); return false; } for (KeySchemaElement keySchemaElement : tableDescription.getKeySchema()) { String attributeName = keySchemaElement.getAttributeName(); if (attributeName.equals("Company")) { if (!keySchemaElement.getKeyType().equals("HASH")) { // We have a matching attribute, but the type is wrong. System.out.println("Company attribute is wrong type in key schema."); return false; } } else if (attributeName.equals("Email")) { if (!keySchemaElement.getKeyType().equals("RANGE")) { // We have a matching attribute, but the type is wrong. System.out.println("Email attribute is wrong type in key schema."); return false; } } else { System.out.println( "Unexpected attribute (" + keySchemaElement.getAttributeName() + ") in the key schema."); } } System.out.println("Table schema is as expected."); // We've passed our checks. return true; } // END NON-STUDENT CODE }