private static void retrieveItem() { Table table = dynamoDB.getTable(tableName); try { Item item = table.getItem("Id", 120, "Id, ISBN, Title, Authors", null); System.out.println("Printing item after retrieving it...."); System.out.println(item.toJSONPretty()); } catch (Exception e) { System.err.println("GetItem failed."); System.err.println(e.getMessage()); } }
private static void getBook(int id, String tableName) { Table table = dynamoDB.getTable(tableName); Item item = table.getItem("Id", // attribute name id, // attribute value "Id, ISBN, Title, Authors", // projection expression null); // name map - don't need this System.out.println("GetItem: printing results..."); System.out.println(item.toJSONPretty()); }
private static void findProductsForPriceLessThanZero() { Table table = dynamoDB.getTable(tableName); Map<String, Object> expressionAttributeValues = new HashMap<String, Object>(); expressionAttributeValues.put(":pr", 100); ItemCollection<ScanOutcome> items = table.scan( "Price < :pr", //FilterExpression "Id, Title, ProductCategory, Price", //ProjectionExpression null, //ExpressionAttributeNames - not used in this example expressionAttributeValues); System.out.println("Scan of " + tableName + " for items with a price less than 100."); Iterator<Item> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
private static void findRepliesInLast15DaysWithConfig(String forumName, String threadSubject) { Table table = dynamoDB.getTable(tableName); long twoWeeksAgoMilli = (new Date()).getTime() - (15L*24L*60L*60L*1000L); Date twoWeeksAgo = new Date(); twoWeeksAgo.setTime(twoWeeksAgoMilli); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); String twoWeeksAgoStr = df.format(twoWeeksAgo); String replyId = forumName + "#" + threadSubject; QuerySpec spec = new QuerySpec() .withProjectionExpression("Message, ReplyDateTime, PostedBy") .withKeyConditionExpression("Id = :v_id and ReplyDateTime <= :v_reply_dt_tm") .withValueMap(new ValueMap() .withString(":v_id", replyId) .withString(":v_reply_dt_tm", twoWeeksAgoStr)); ItemCollection<QueryOutcome> items = table.query(spec); System.out.println("\nfindRepliesInLast15DaysWithConfig results:"); Iterator<Item> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
private static void findRepliesPostedWithinTimePeriod(String forumName, String threadSubject) { Table table = dynamoDB.getTable(tableName); long startDateMilli = (new Date()).getTime() - (15L*24L*60L*60L*1000L); long endDateMilli = (new Date()).getTime() - (5L*24L*60L*60L*1000L); java.text.SimpleDateFormat df = new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); String startDate = df.format(startDateMilli); String endDate = df.format(endDateMilli); String replyId = forumName + "#" + threadSubject; QuerySpec spec = new QuerySpec() .withProjectionExpression("Message, ReplyDateTime, PostedBy") .withKeyConditionExpression("Id = :v_id and ReplyDateTime between :v_start_dt and :v_end_dt") .withValueMap(new ValueMap() .withString(":v_id", replyId) .withString(":v_start_dt", startDate) .withString(":v_end_dt", endDate)); ItemCollection<QueryOutcome> items = table.query(spec); System.out.println("\nfindRepliesPostedWithinTimePeriod results:"); Iterator<Item> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
private static void findRepliesForAThread(String forumName, String threadSubject) { Table table = dynamoDB.getTable(tableName); String replyId = forumName + "#" + threadSubject; QuerySpec spec = new QuerySpec() .withKeyConditionExpression("Id = :v_id") .withValueMap(new ValueMap() .withString(":v_id", replyId)); ItemCollection<QueryOutcome> items = table.query(spec); System.out.println("\nfindRepliesForAThread results:"); Iterator<Item> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
List<Item> items = outcome.getTableItems().get(tableName); for (Item item : items) { System.out.println(item.toJSONPretty());
private static void findRepliesInLast15DaysWithConfig( String tableName, String forumName, String threadSubject) { String replyId = forumName + "#" + threadSubject; long twoWeeksAgoMilli = (new Date()).getTime() - (15L * 24L * 60L * 60L * 1000L); Date twoWeeksAgo = new Date(); twoWeeksAgo.setTime(twoWeeksAgoMilli); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); String twoWeeksAgoStr = df.format(twoWeeksAgo); Table table = dynamoDB.getTable(tableName); QuerySpec querySpec = new QuerySpec() .withKeyConditionExpression("Id = :v1 and ReplyDateTime > :v2") .withValueMap(new ValueMap() .withString(":v1", replyId) .withString(":v2", twoWeeksAgoStr)) .withProjectionExpression("Message, ReplyDateTime, PostedBy"); ItemCollection<QueryOutcome> items = table.query(querySpec); Iterator<Item> iterator = items.iterator(); System.out.println("Query: printing results..."); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
private static void findRepliesForAThreadSpecifyOptionalLimit(String forumName, String threadSubject) { Table table = dynamoDB.getTable(tableName); String replyId = forumName + "#" + threadSubject; QuerySpec spec = new QuerySpec() .withKeyConditionExpression("Id = :v_id") .withValueMap(new ValueMap() .withString(":v_id", replyId)) .withMaxPageSize(1); ItemCollection<QueryOutcome> items = table.query(spec); System.out.println("\nfindRepliesForAThreadSpecifyOptionalLimit results:"); // Process each page of results int pageNum = 0; for (Page<Item, QueryOutcome> page : items.pages()) { System.out.println("\nPage: " + ++pageNum); // Process each item on the current page Iterator<Item> item = page.iterator(); while (item.hasNext()) { System.out.println(item.next().toJSONPretty()); } } }
public static void main(String[] args) { AmazonDynamoDBClient client = new AmazonDynamoDBClient(); client.setEndpoint("http://localhost:8000"); DynamoDB dynamoDB = new DynamoDB(client); Table table = dynamoDB.getTable("Movies"); int year = 2015; String title = "The Big New Movie"; try { table.putItem(new Item() .withPrimaryKey("year", year, "title", title) .withJSON("info", "{\"plot\" : \"Something happens.\"}")); System.out.println("PutItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty()); } catch (Exception e) { System.out.println("PutItem failed"); e.printStackTrace(); } } }
private static void updateAddNewAttribute() { Table table = dynamoDB.getTable(tableName); try { Map<String, String> expressionAttributeNames = new HashMap<String, String>(); expressionAttributeNames.put("#na", "NewAttribute"); UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey("Id", 121) .withUpdateExpression("set #na = :val1") .withNameMap(new NameMap() .with("#na", "NewAttribute")) .withValueMap(new ValueMap() .withString(":val1", "Some value")) .withReturnValues(ReturnValue.ALL_NEW); UpdateItemOutcome outcome = table.updateItem(updateItemSpec); // Check the response. System.out.println("Printing item after adding new attribute..."); System.out.println(outcome.getItem().toJSONPretty()); } catch (Exception e) { System.err.println("Failed to add new attribute in " + tableName); System.err.println(e.getMessage()); } }
private static void findRepliesUsingAFilterExpression(String forumName, String threadSubject) { Table table = dynamoDB.getTable(tableName); String replyId = forumName + "#" + threadSubject; QuerySpec spec = new QuerySpec() .withProjectionExpression("Message, ReplyDateTime, PostedBy") .withKeyConditionExpression("Id = :v_id") .withFilterExpression("PostedBy = :v_postedby") .withValueMap(new ValueMap() .withString(":v_id", replyId) .withString(":v_postedby", "User B")); ItemCollection<QueryOutcome> items = table.query(spec); System.out.println("\nfindRepliesUsingAFilterExpression results:"); Iterator<Item> iterator = items.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toJSONPretty()); } }
private static void deleteItem() { Table table = dynamoDB.getTable(tableName); try { DeleteItemSpec deleteItemSpec = new DeleteItemSpec() .withPrimaryKey("Id", 120) .withConditionExpression("#ip = :val") .withNameMap(new NameMap() .with("#ip", "InPublication")) .withValueMap(new ValueMap() .withBoolean(":val", false)) .withReturnValues(ReturnValue.ALL_OLD); DeleteItemOutcome outcome = table.deleteItem(deleteItemSpec); // Check the response. System.out.println("Printing item that was deleted..."); System.out.println(outcome.getItem().toJSONPretty()); } catch (Exception e) { System.err.println("Error deleting item in " + tableName); System.err.println(e.getMessage()); } } }
public static void main(String[] args) { AmazonDynamoDBClient client = new AmazonDynamoDBClient(); client.setEndpoint("http://localhost:8000"); DynamoDB dynamoDB = new DynamoDB(client); Table table = dynamoDB.getTable("Movies"); int year = 2015; String title = "The Big New Movie"; UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey("year", year, "title", title) .withUpdateExpression("set info.rating = info.rating + :val") .withValueMap(new ValueMap() .withNumber(":val", 1)); System.out.println("Incrementing an atomic counter..."); try { table.updateItem(updateItemSpec); System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty()); } catch (Exception e) { System.out.println("UpdateItem failed"); e.printStackTrace(); } }
public static void main(String[] args) { AmazonDynamoDBClient client = new AmazonDynamoDBClient(); client.setEndpoint("http://localhost:8000"); DynamoDB dynamoDB = new DynamoDB(client); Table table = dynamoDB.getTable("Movies"); int year = 2015; String title = "The Big New Movie"; UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey("year", year, "title", title) .withUpdateExpression("set info.rating = :r, info.plot=:p, info.actors=:a") .withValueMap(new ValueMap() .withNumber(":r", 5.5) .withString(":p", "Everything happens all at once.") .withList(":a", Arrays.asList("Larry","Moe","Curly"))); System.out.println("Updating the item..."); try { table.updateItem(updateItemSpec); System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty()); } catch (Exception e) { System.out.println("UpdateItem failed"); e.printStackTrace(); } }
private static void updateMultipleAttributes() { Table table = dynamoDB.getTable(tableName); try { UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey("Id", 120) .withUpdateExpression("add #a :val1 set #na=:val2") .withNameMap(new NameMap() .with("#a", "Authors") .with("#na", "NewAttribute")) .withValueMap(new ValueMap() .withStringSet(":val1", "Author YY", "Author ZZ") .withString(":val2", "someValue")) .withReturnValues(ReturnValue.ALL_NEW); UpdateItemOutcome outcome = table.updateItem(updateItemSpec); // Check the response. System.out .println("Printing item after multiple attribute update..."); System.out.println(outcome.getItem().toJSONPretty()); } catch (Exception e) { System.err.println("Failed to update multiple attributes in " + tableName); System.err.println(e.getMessage()); } }
private static void updateExistingAttributeConditionally() { Table table = dynamoDB.getTable(tableName); try { // Specify the desired price (25.00) and also the condition (price = // 20.00) UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey("Id", 120) .withReturnValues(ReturnValue.ALL_NEW) .withUpdateExpression("set #p = :val1") .withConditionExpression("#p = :val2") .withNameMap(new NameMap() .with("#p", "Price")) .withValueMap(new ValueMap() .withNumber(":val1", 25) .withNumber(":val2", 20)); UpdateItemOutcome outcome = table.updateItem(updateItemSpec); // Check the response. System.out .println("Printing item after conditional update to new attribute..."); System.out.println(outcome.getItem().toJSONPretty()); } catch (Exception e) { System.err.println("Error updating item in " + tableName); System.err.println(e.getMessage()); } }
System.out.println(iterator.next().toJSONPretty());
try { table.putItem(putItemSpec); System.out.println("PutItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty()); } catch (ConditionalCheckFailedException e) { e.printStackTrace(System.err);
public static void main(String[] args) { AmazonDynamoDBClient client = new AmazonDynamoDBClient(); client.setEndpoint("http://localhost:8000"); DynamoDB dynamoDB = new DynamoDB(client); Table table = dynamoDB.getTable("Movies"); int year = 2015; String title = "The Big New Movie"; // Conditional update (will fail) UpdateItemSpec updateItemSpec = new UpdateItemSpec() .withPrimaryKey(new PrimaryKey("year", 2015, "title", "The Big New Movie")) .withUpdateExpression("remove info.actors[0]") .withConditionExpression("size(info.actors) > :num") .withValueMap(new ValueMap().withNumber(":num", 3)); System.out.println("Attempting a conditional update..."); try { table.updateItem(updateItemSpec); System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty()); } catch (ConditionalCheckFailedException e) { e.printStackTrace(); System.out.println("UpdateItem failed"); } } }