com.amazonaws.services.dynamodbv2.document.spec.ScanSpec Java Examples

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");
        
        ScanSpec scanSpec = new ScanSpec()
            .withProjectionExpression("#yr, title, info.rating")
            .withFilterExpression("#yr between :start_yr and :end_yr")
            .withNameMap(new NameMap().with("#yr",  "year"))
            .withValueMap(new ValueMap().withNumber(":start_yr", 1950).withNumber(":end_yr", 1959));
        
        ItemCollection<ScanOutcome> items = table.scan(scanSpec);
        
        Iterator<Item> iter = items.iterator();
        while (iter.hasNext()) {
            Item item = iter.next();
            System.out.println(item.toString());
        }
    }
 

@Override
public final Response scan(final Request request) {
    final Table table = dynamoDB.getTable(request.getTableName());

    final String projectionExpression = request.getPartitionKey() + " , " + request.getSortKey();
    final ScanSpec scanSpec = new ScanSpec()
            .withProjectionExpression(projectionExpression);

    StringBuilder filterExpressionBuilder;
    Map<String, Object> valueMap;
    if (request.getFilterData() != null) {
        filterExpressionBuilder = new StringBuilder();
        valueMap = new HashMap<>();
        processFilterData(request, filterExpressionBuilder, valueMap);
        // Add to ScanSpec.
        scanSpec.withFilterExpression(filterExpressionBuilder.toString());
        scanSpec.withValueMap(valueMap);
    }

    ItemCollection<ScanOutcome> scanItems = table.scan(scanSpec);

    final StringBuilder response = new StringBuilder();
    response.append("PK of items read with scan (V1): ");
    for (Item item : scanItems) {
        response.append(prepareKeyStr(item, request));
    }

    return new Response(response.toString(), null);
}
 

public static void main(String[] args) throws Exception {

        AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard()
            .withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration("http://localhost:8000", "us-west-2"))
            .build();

        DynamoDB dynamoDB = new DynamoDB(client);

        Table table = dynamoDB.getTable("Movies");

        ScanSpec scanSpec = new ScanSpec().withProjectionExpression("#yr, title, info.rating")
            .withFilterExpression("#yr between :start_yr and :end_yr").withNameMap(new NameMap().with("#yr", "year"))
            .withValueMap(new ValueMap().withNumber(":start_yr", 1950).withNumber(":end_yr", 1959));

        try {
            ItemCollection<ScanOutcome> items = table.scan(scanSpec);

            Iterator<Item> iter = items.iterator();
            while (iter.hasNext()) {
                Item item = iter.next();
                System.out.println(item.toString());
            }

        }
        catch (Exception e) {
            System.err.println("Unable to scan the table:");
            System.err.println(e.getMessage());
        }
    }
 

@Override
public void run() {
    System.out.println("Scanning " + tableName + " segment " + segment + " out of " + totalSegments
        + " segments " + itemLimit + " items at a time...");
    int totalScannedItemCount = 0;

    Table table = dynamoDB.getTable(tableName);

    try {
        ScanSpec spec = new ScanSpec().withMaxResultSize(itemLimit).withTotalSegments(totalSegments)
            .withSegment(segment);

        ItemCollection<ScanOutcome> items = table.scan(spec);
        Iterator<Item> iterator = items.iterator();

        Item currentItem = null;
        while (iterator.hasNext()) {
            totalScannedItemCount++;
            currentItem = iterator.next();
            System.out.println(currentItem.toString());
        }

    }
    catch (Exception e) {
        System.err.println(e.getMessage());
    }
    finally {
        System.out.println("Scanned " + totalScannedItemCount + " items from segment " + segment + " out of "
            + totalSegments + " of " + tableName);
    }
}
 

@Override
public void run() {
    System.out.println("Scanning " + tableName + " segment " + segment + " out of " + totalSegments + " segments " + itemLimit + " items at a time...");
    int totalScannedItemCount = 0;

    Table table = dynamoDB.getTable(tableName);
    
    try {
        ScanSpec spec = new ScanSpec()
            .withMaxResultSize(itemLimit)
            .withTotalSegments(totalSegments)
            .withSegment(segment);
        
        ItemCollection<ScanOutcome> items = table.scan(spec);
        Iterator<Item> iterator = items.iterator();
          
        Item currentItem = null;
        while (iterator.hasNext()) {
            totalScannedItemCount++;
            currentItem = iterator.next();
            System.out.println(currentItem.toString());
        }    
            
    } catch (Exception e) {
        System.err.println(e.getMessage());
    } finally {
        System.out.println("Scanned " + totalScannedItemCount 
            + " items from segment " + segment + " out of " 
            + totalSegments + " of " + tableName);
    }
}
 

private Set<String> getAuthorizedSpaces(Marker marker, SpaceAuthorizationCondition authorizedCondition) throws AmazonDynamoDBException {
  final Set<String> authorizedSpaces = new LinkedHashSet<>();

  logger.info(marker, "Getting authorized spaces by condition");

  try {
    // get the space ids which are authorized by the authorizedCondition
    if (authorizedCondition.spaceIds != null) {
      authorizedSpaces.addAll(authorizedCondition.spaceIds);
      logger.debug(marker, "Number of space IDs after addition from authorized condition space IDs: {}", authorizedSpaces.size());
    }

    // then get the owners which are authorized by the authorizedCondition
    if (authorizedCondition.ownerIds != null) {
      authorizedCondition.ownerIds.forEach(owner ->
          spaces.getIndex("owner-index").query("owner", owner).pages().forEach(p -> p.forEach(i -> {
            authorizedSpaces.add(i.getString("id"));
          }))
      );
      logger.debug(marker, "Number of space IDs after addition from owners: {}", authorizedSpaces.size());
    }

    // then get the packages which are authorized by the authorizedCondition
    if (authorizedCondition.packages != null) {
      authorizedCondition.packages.forEach(packageName ->
          packages.query("packageName", packageName).pages().forEach(p -> p.forEach(i -> {
            authorizedSpaces.add(i.getString("spaceId"));
          }))
      );
      logger.debug(marker, "Number of space IDs after addition from packages: {}", authorizedSpaces.size());
    }

    // then get the "empty" case, when no spaceIds or ownerIds os packages are provided, meaning select ALL spaces
    if (CollectionUtils.isNullOrEmpty(authorizedCondition.spaceIds)
        && CollectionUtils.isNullOrEmpty(authorizedCondition.ownerIds)
        && CollectionUtils.isNullOrEmpty(authorizedCondition.packages)) {
      spaces.scan(new ScanSpec().withProjectionExpression("id")).pages()
          .forEach(p -> p.forEach(i -> authorizedSpaces.add(i.getString("id"))));
    }
  } catch (AmazonDynamoDBException e) {
    logger.error(marker, "Failure to get the authorized spaces", e);
    throw e;
  }

  logger.info(marker, "Returning the list of authorized spaces with size of: {}", authorizedSpaces.size());
  return authorizedSpaces;
}
 

@AfterEach
public void truncateLockTable() {
    for (Item item : lockTable.scan(new ScanSpec())) {
        lockTable.deleteItem(new PrimaryKey(ID, item.getString(ID)));
    }
}