LowLevelScan.java

/*
* Copyright 2014-2015 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.
*/
package com.amazonaws.codesamples.lowlevel;

import java.util.HashMap;
import java.util.Map;


import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodbv2.model.AttributeValue;
import com.amazonaws.services.dynamodbv2.model.ScanRequest;
import com.amazonaws.services.dynamodbv2.model.ScanResult;

public class LowLevelScan {

    static AmazonDynamoDBClient client = new AmazonDynamoDBClient(new ProfileCredentialsProvider());
    static String tableName = "ProductCatalog";

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

        findProductsForPriceLessThanZero();
    }


    private static void findProductsForPriceLessThanZero() {
        
        Map<String, AttributeValue> expressionAttributeValues = new HashMap<String, AttributeValue>();
        expressionAttributeValues.put(":pr", new AttributeValue().withN("100"));
        
        ScanRequest scanRequest = new ScanRequest()
            .withTableName(tableName)
            .withFilterExpression("Price < :pr")
            .withExpressionAttributeValues(expressionAttributeValues)
            .withProjectionExpression("Id, Title, ProductCategory, Price");

        ScanResult result = client.scan(scanRequest);
        
        System.out.println("Scan of " + tableName + " for items with a price less than 100.");
        for (Map<String, AttributeValue> item : result.getItems()) {
            System.out.println("");
            printItem(item);
        }
    }
    
    private static void printItem(Map<String, AttributeValue> attributeList) {
        for (Map.Entry<String, AttributeValue> item : attributeList.entrySet()) {
            String attributeName = item.getKey();
            AttributeValue value = item.getValue();
            System.out.println(attributeName + " "
                    + (value.getS() == null ? "" : "S=[" + value.getS() + "]")
                    + (value.getN() == null ? "" : "N=[" + value.getN() + "]")
                    + (value.getB() == null ? "" : "B=[" + value.getB() + "]")
                    + (value.getSS() == null ? "" : "SS=[" + value.getSS() + "]")
                    + (value.getNS() == null ? "" : "NS=[" + value.getNS() + "]")
                    + (value.getBS() == null ? "" : "BS=[" + value.getBS() + "] \n"));
        }
    }
}