Examples with AttributeValueUpdate com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate used on opensource projects

Example 11 with AttributeValueUpdate

use of com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate in project aws-doc-sdk-examples by awsdocs.

the class UpdateItem method main.

public static void main(String[] args) {
    final String USAGE = "\n" + "Usage:\n" + "    UpdateItem <table> <name> <greeting>\n\n" + "Where:\n" + "    table    - the table to put the item in.\n" + "    name     - a name to update in the table. The name must exist,\n" + "               or an error will result.\n" + "Additional fields can be specified by appending them to the end of the\n" + "input.\n\n" + "Examples:\n" + "    UpdateItem SiteColors text default=000000 bold=b22222\n" + "    UpdateItem SiteColors background default=eeeeee code=d3d3d3\n\n";
    if (args.length < 3) {
        System.out.println(USAGE);
        System.exit(1);
    }
    String table_name = args[0];
    String name = args[1];
    ArrayList<String[]> extra_fields = new ArrayList<String[]>();
    // any additional args (fields to add or update)?
    for (int x = 2; x < args.length; x++) {
        String[] fields = args[x].split("=", 2);
        if (fields.length == 2) {
            extra_fields.add(fields);
        } else {
            System.out.format("Invalid argument: %s\n", args[x]);
            System.out.println(USAGE);
            System.exit(1);
        }
    }
    System.out.format("Updating \"%s\" in %s\n", name, table_name);
    if (extra_fields.size() > 0) {
        System.out.println("Additional fields:");
        for (String[] field : extra_fields) {
            System.out.format("  %s: %s\n", field[0], field[1]);
        }
    }
    HashMap<String, AttributeValue> item_key = new HashMap<String, AttributeValue>();
    item_key.put("Name", new AttributeValue(name));
    HashMap<String, AttributeValueUpdate> updated_values = new HashMap<String, AttributeValueUpdate>();
    for (String[] field : extra_fields) {
        updated_values.put(field[0], new AttributeValueUpdate(new AttributeValue(field[1]), AttributeAction.PUT));
    }
    final AmazonDynamoDB ddb = AmazonDynamoDBClientBuilder.defaultClient();
    try {
        ddb.updateItem(table_name, item_key, updated_values);
    } catch (ResourceNotFoundException e) {
        System.err.println(e.getMessage());
        System.exit(1);
    } catch (AmazonServiceException e) {
        System.err.println(e.getMessage());
        System.exit(1);
    }
    System.out.println("Done!");
}

Example 12 with AttributeValueUpdate

use of com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate in project aws-doc-sdk-examples by awsdocs.

the class StreamsLowLevelDemo method main.

public static void main(String[] args) throws InterruptedException {
    AmazonDynamoDB dynamoDBClient = AmazonDynamoDBClientBuilder.standard().withRegion(Regions.US_EAST_2).withCredentials(new DefaultAWSCredentialsProviderChain()).build();
    AmazonDynamoDBStreams streamsClient = AmazonDynamoDBStreamsClientBuilder.standard().withRegion(Regions.US_EAST_2).withCredentials(new DefaultAWSCredentialsProviderChain()).build();
    // Create a table, with a stream enabled
    String tableName = "TestTableForStreams";
    ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<>(Arrays.asList(new AttributeDefinition().withAttributeName("Id").withAttributeType("N")));
    ArrayList<KeySchemaElement> keySchema = new ArrayList<>(Arrays.asList(new KeySchemaElement().withAttributeName("Id").withKeyType(// Partition key
    KeyType.HASH)));
    StreamSpecification streamSpecification = new StreamSpecification().withStreamEnabled(true).withStreamViewType(StreamViewType.NEW_AND_OLD_IMAGES);
    CreateTableRequest createTableRequest = new CreateTableRequest().withTableName(tableName).withKeySchema(keySchema).withAttributeDefinitions(attributeDefinitions).withProvisionedThroughput(new ProvisionedThroughput().withReadCapacityUnits(10L).withWriteCapacityUnits(10L)).withStreamSpecification(streamSpecification);
    System.out.println("Issuing CreateTable request for " + tableName);
    dynamoDBClient.createTable(createTableRequest);
    System.out.println("Waiting for " + tableName + " to be created...");
    try {
        TableUtils.waitUntilActive(dynamoDBClient, tableName);
    } catch (AmazonClientException e) {
        e.printStackTrace();
    }
    // Print the stream settings for the table
    DescribeTableResult describeTableResult = dynamoDBClient.describeTable(tableName);
    String streamArn = describeTableResult.getTable().getLatestStreamArn();
    System.out.println("Current stream ARN for " + tableName + ": " + describeTableResult.getTable().getLatestStreamArn());
    StreamSpecification streamSpec = describeTableResult.getTable().getStreamSpecification();
    System.out.println("Stream enabled: " + streamSpec.getStreamEnabled());
    System.out.println("Update view type: " + streamSpec.getStreamViewType());
    System.out.println();
    // Generate write activity in the table
    System.out.println("Performing write activities on " + tableName);
    int maxItemCount = 100;
    for (Integer i = 1; i <= maxItemCount; i++) {
        System.out.println("Processing item " + i + " of " + maxItemCount);
        // Write a new item
        Map<String, AttributeValue> item = new HashMap<>();
        item.put("Id", new AttributeValue().withN(i.toString()));
        item.put("Message", new AttributeValue().withS("New item!"));
        dynamoDBClient.putItem(tableName, item);
        // Update the item
        Map<String, AttributeValue> key = new HashMap<>();
        key.put("Id", new AttributeValue().withN(i.toString()));
        Map<String, AttributeValueUpdate> attributeUpdates = new HashMap<>();
        attributeUpdates.put("Message", new AttributeValueUpdate().withAction(AttributeAction.PUT).withValue(new AttributeValue().withS("This item has changed")));
        dynamoDBClient.updateItem(tableName, key, attributeUpdates);
        // Delete the item
        dynamoDBClient.deleteItem(tableName, key);
    }
    // Get all the shard IDs from the stream.  Note that DescribeStream returns
    // the shard IDs one page at a time.
    String lastEvaluatedShardId = null;
    do {
        DescribeStreamResult describeStreamResult = streamsClient.describeStream(new DescribeStreamRequest().withStreamArn(streamArn).withExclusiveStartShardId(lastEvaluatedShardId));
        List<Shard> shards = describeStreamResult.getStreamDescription().getShards();
        for (Shard shard : shards) {
            String shardId = shard.getShardId();
            System.out.println("Shard: " + shard);
            // Get an iterator for the current shard
            GetShardIteratorRequest getShardIteratorRequest = new GetShardIteratorRequest().withStreamArn(streamArn).withShardId(shardId).withShardIteratorType(ShardIteratorType.TRIM_HORIZON);
            GetShardIteratorResult getShardIteratorResult = streamsClient.getShardIterator(getShardIteratorRequest);
            String currentShardIter = getShardIteratorResult.getShardIterator();
            // Shard iterator is not null until the Shard is sealed (marked as READ_ONLY).
            // To prevent running the loop until the Shard is sealed, which will be on average
            // 4 hours, we process only the items that were written into DynamoDB and then exit.
            int processedRecordCount = 0;
            while (currentShardIter != null && processedRecordCount < maxItemCount) {
                System.out.println("    Shard iterator: " + currentShardIter.substring(380));
                // Use the shard iterator to read the stream records
                GetRecordsResult getRecordsResult = streamsClient.getRecords(new GetRecordsRequest().withShardIterator(currentShardIter));
                List<Record> records = getRecordsResult.getRecords();
                for (Record record : records) {
                    System.out.println("        " + record.getDynamodb());
                }
                processedRecordCount += records.size();
                currentShardIter = getRecordsResult.getNextShardIterator();
            }
        }
        // If LastEvaluatedShardId is set, then there is
        // at least one more page of shard IDs to retrieve
        lastEvaluatedShardId = describeStreamResult.getStreamDescription().getLastEvaluatedShardId();
    } while (lastEvaluatedShardId != null);
    // Delete the table
    System.out.println("Deleting the table...");
    dynamoDBClient.deleteTable(tableName);
    System.out.println("Demo complete");
}