Scan items for DynamoDB

Description

Demo Code

/*//  www  .  j  a v a2s. c  o  m
 * Copyright 2012-2014 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.
 */
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
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.ComparisonOperator;
import com.amazonaws.services.dynamodbv2.model.Condition;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.DescribeTableRequest;
import com.amazonaws.services.dynamodbv2.model.KeySchemaElement;
import com.amazonaws.services.dynamodbv2.model.KeyType;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.PutItemRequest;
import com.amazonaws.services.dynamodbv2.model.PutItemResult;
import com.amazonaws.services.dynamodbv2.model.ScalarAttributeType;
import com.amazonaws.services.dynamodbv2.model.ScanRequest;
import com.amazonaws.services.dynamodbv2.model.ScanResult;
import com.amazonaws.services.dynamodbv2.model.TableDescription;
import com.amazonaws.services.dynamodbv2.util.Tables;

/**
 * This sample demonstrates how to perform a few simple operations with the
 * Amazon DynamoDB service.
 */
public class RandomQuery1OnDynamoDB {

    /*
     * WANRNING: To avoid accidental leakage of your credentials, DO NOT keep
     * the credentials file in your source directory.
     */

    static AmazonDynamoDBClient dynamoDB;
    static AmazonDynamoDBClient client = new AmazonDynamoDBClient(
            new ProfileCredentialsProvider());
    static String tableName = "weather-100k";

    /**
     * The only information needed to create a client are security credentials
     * consisting of the AWS Access Key ID and Secret Access Key. All other
     * configuration, such as the service endpoints, are performed
     * automatically. Client parameters, such as proxies, can be specified in an
     * optional ClientConfiguration object when constructing a client.
     * 
     * @see com.amazonaws.auth.BasicAWSCredentials
     * @see com.amazonaws.auth.ProfilesConfigFile
     * @see com.amazonaws.ClientConfiguration
     */
    private static void init() throws Exception {
        /*
         * The ProfileCredentialsProvider will return your [default] credential
         * profile by reading from the credentials file located at
         * (C:\\Users\\Divendar\\.aws\\credentials).
         */

        AWSCredentials credentials = null;
        try {
            credentials = new ProfileCredentialsProvider("default")
                    .getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException(
                    "Cannot load the credentials from the credential profiles file. "
                            + "Please make sure that your credentials file is at the correct "
                            + "location (C:\\Users\\Divendar\\.aws\\credentials), and is in valid format.",
                    e);
        }
        dynamoDB = new AmazonDynamoDBClient(credentials);
        Region usWest2 = Region.getRegion(Regions.US_WEST_2);
        dynamoDB.setRegion(usWest2);
    }

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

        try {

            // Describe our new table
            DescribeTableRequest describeTableRequest = new DescribeTableRequest()
                    .withTableName(tableName);
            TableDescription tableDescription = dynamoDB.describeTable(
                    describeTableRequest).getTable();
            System.out.println("Table Description: " + tableDescription);

            System.out.println("Table count :"
                    + tableDescription.getItemCount());

            long lStartTime = new Date().getTime();
            System.out.println("start time: " + lStartTime);
            Random rn = new Random();
            // Scan items for movies with a year attribute greater than 1985
            Long lItem = tableDescription.getItemCount();
            int iNoOfItems = lItem.intValue();
            System.out.println("no of item " + lItem);
            for (int i = 0; i <= 49999; i++) {
                String randomInt = Integer.toString(rn.nextInt(iNoOfItems));
                HashMap<String, Condition> scanFilter = new HashMap<String, Condition>();
                Condition condition = new Condition()
                        .withComparisonOperator(
                                ComparisonOperator.EQ.toString())
                        .withAttributeValueList(
                                new AttributeValue().withN(randomInt));
                scanFilter.put("id", condition);
                ScanRequest scanRequest = new ScanRequest(tableName)
                        .withScanFilter(scanFilter);
                ScanResult scanResult = dynamoDB.scan(scanRequest);
                System.out.println("Random No :" + randomInt
                        + ":: Query no: " + (i + 1));

            }
            // calculate time difference for update file time
            long lEndTime = new Date().getTime();
            long difference = lEndTime - lStartTime;
            System.out.println("Elapsed milliseconds: " + difference);
            System.out.println("Elapsed seconds: " + difference * 0.001);
            System.out.println("Elapsed Minutes: "
                    + (int) ((difference / (1000 * 60)) % 60));

        } catch (AmazonServiceException ase) {
            System.out
                    .println("Caught an AmazonServiceException, which means your request made it "
                            + "to AWS, but was rejected with an error response for some reason.");
            System.out.println("Error Message:    " + ase.getMessage());
            System.out.println("HTTP Status Code: " + ase.getStatusCode());
            System.out.println("AWS Error Code:   " + ase.getErrorCode());
            System.out.println("Error Type:       " + ase.getErrorType());
            System.out.println("Request ID:       " + ase.getRequestId());
        } catch (AmazonClientException ace) {
            System.out
                    .println("Caught an AmazonClientException, which means the client encountered "
                            + "a serious internal problem while trying to communicate with AWS, "
                            + "such as not being able to access the network.");
            System.out.println("Error Message: " + ace.getMessage());
        }
    }

}
Scan items for DynamoDB - Java AWS

Description

Demo Code

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