Example usage for com.amazonaws.services.dynamodbv2.document ScanFilter ScanFilter

Introduction

In this page you can find the example usage for com.amazonaws.services.dynamodbv2.document ScanFilter ScanFilter.

Prototype

public ScanFilter(String attr) 

Source Link

Document

A <a href="http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Scan.html#DDB-Scan-request-ScanFilter" >scan filter</a>.

Usage

From source file:com.github.sdmcraft.slingdynamo.impl.DynamoDBResourceProvider.java

License:Open Source License

/**
 * Returns a resource from this resource provider or null if the resource provider cannot find it.
 * The table-name, id and child-ids are parsed out from the path and queried against dynamodb to fetch the specified resource.
 *
 * @param resolver the ResourceResolver to which the returned Resource is attached.
 * @param req the HttpServletRequest made to get this resource
 * @param path the path of the resource. The path is of the format <table-name>/<id>/[<child-id1>/.../<child-idn>]
 * @return the resource at the specified path if it exists else returns null
 *///from   w  w w  . j  a v  a2 s. c  o m
public Resource getResource(ResourceResolver resolver, HttpServletRequest req, String path) {
    Resource resource = null;

    try {
        Map<String, Object> resourceProps = new HashMap<String, Object>();
        ResourceMetadata resourceMetadata = new ResourceMetadata();
        resourceMetadata.setResolutionPath(path);

        if (!path.contains(".")) {
            if (path.length() > root.length()) {
                String subPath = path.substring(root.length() + 1);
                String[] subPathSplits = subPath.split("/");
                String table = subPathSplits[0];
                resourceMetadata.put("table", table);

                Table dbtable = dynamoDB.getTable(table);

                if (subPathSplits.length == 1) {
                    DescribeTableRequest describeTableRequest = new DescribeTableRequest(table);
                    DescribeTableResult describeTableResult = null;

                    describeTableResult = dynamoDBClient.describeTable(describeTableRequest);

                    Date creationDate = describeTableResult.getTable().getCreationDateTime();
                    long itemCount = describeTableResult.getTable().getItemCount();

                    resourceProps.put("creation-date", creationDate);
                    resourceProps.put("record-count", itemCount);
                    resourceProps.put("table-name", table);
                } else if (subPathSplits.length == 2) {
                    int id = Integer.parseInt(subPathSplits[1]);
                    ScanFilter idFilter = new ScanFilter("id").eq(id);
                    ItemCollection<ScanOutcome> items = dbtable.scan(idFilter);
                    Iterator<Item> itemItr = items.iterator();

                    Item item = itemItr.next();
                    resourceProps = itemToMap(item);
                } else if (subPathSplits.length > 2) {
                    int parent = Integer.parseInt(subPathSplits[1]);
                    Item item = null;

                    for (int i = 2; i < subPathSplits.length; i++) {
                        int child = Integer.parseInt(subPathSplits[i]);
                        ScanFilter parentFilter = new ScanFilter("parent").eq(parent);
                        ScanFilter childFilter = new ScanFilter("child_id").eq(child);
                        ItemCollection<ScanOutcome> items = dbtable.scan(parentFilter, childFilter);
                        Iterator<Item> itemItr = items.iterator();
                        item = itemItr.next();
                        parent = item.getInt("id");
                    }

                    resourceProps = itemToMap(item);
                }
            }

            resourceProps.put("hello", "world");

            ModifiableValueMapDecorator valueMap = new ModifiableValueMapDecorator(resourceProps);

            resource = new DynamoDBResource(resolver, resourceMetadata, valueMap, resourceType);
        }
    } catch (Throwable ex) {
        LOGGER.error(ex.getMessage(), ex);
        throw new RuntimeException(ex);
    }

    return resource;
}

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From source file:com.github.sdmcraft.slingdynamo.impl.DynamoDBResourceProvider.java

License:Open Source License

/**
 * Gets the children./*  ww  w . j a v a  2  s .co m*/
 *
 * @param dbtable the dbtable
 * @param parent the parent
 * @param childIds the child ids
 * @param path the path
 * @param resolver the resolver
 * @return the children
 */
private List<Resource> getChildren(Table dbtable, int parent, Object[] childIds, String path,
        ResourceResolver resolver) {
    ScanFilter idFilter = new ScanFilter("parent").in(parent);
    ScanFilter childIdsFilter = new ScanFilter("child_id").in(childIds);
    ItemCollection<ScanOutcome> items = dbtable.scan(idFilter, childIdsFilter);
    Iterator<Item> itemItr = items.iterator();
    List<Resource> children = new ArrayList<Resource>();

    while (itemItr.hasNext()) {
        Item item = itemItr.next();
        Iterable<Entry<String, Object>> attributes = item.attributes();
        Iterator<Entry<String, Object>> attributesItr = attributes.iterator();
        Map<String, Object> resourceProps = new HashMap<String, Object>();

        while (attributesItr.hasNext()) {
            Entry<String, Object> attribute = attributesItr.next();
            resourceProps.put(attribute.getKey(), attribute.getValue());
        }

        ModifiableValueMapDecorator valueMap = new ModifiableValueMapDecorator(resourceProps);
        ResourceMetadata resourceMetadata = new ResourceMetadata();
        resourceMetadata.setResolutionPath(path + '/' + resourceProps.get("child_id"));
        resourceMetadata.put("table", dbtable.getTableName());

        children.add(new DynamoDBResource(resolver, resourceMetadata, valueMap, resourceType));
    }

    return children;
}

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