DynamoDB - Load Table

Loading a table generally consists of creating a source file, ensuring the source file conforms to a syntax compatible with DynamoDB, sending the source file to the destination, and then confirming a successful population.

Utipze the GUI console, Java, or another option to perform the task.

Load Table using GUI Console

Load data using a combination of the command pne and console. You can load data in multiple ways, some of which are as follows −

The Console

The Command Line

Code and also

Data Pipepne (a feature discussed later in the tutorial)

However, for speed, this example uses both the shell and console. First, load the source data into the destination with the following syntax −

aws dynamodb batch-write-item -–request-items file://[filename]

For example −

aws dynamodb batch-write-item -–request-items file://MyProductData.json

Verify the success of the operation by accessing the console at −

https://console.aws.amazon.com/dynamodb

Choose Tables from the navigation pane, and select the destination table from the table pst.

Select the Items tab to examine the data you used to populate the table. Select Cancel to return to the table pst.

Load Table using Java

Employ Java by first creating a source file. Our source file uses JSON format. Each product has two primary key attributes (ID and Nomenclature) and a JSON map (Stat) −

[ 
   { 
      "ID" : ... , 
      "Nomenclature" : ... , 
      "Stat" : { ... }
   }, 
   { 
      "ID" : ... , 
      "Nomenclature" : ... , 
      "Stat" : { ... } 
   }, 
    ... 
] 

You can review the following example −

{ 
   "ID" : 122, 
   "Nomenclature" : "Particle Blaster 5000", 
   "Stat" : { 
      "Manufacturer" : "XYZ Inc.", 
      "sales" : "1M+", 
      "quantity" : 500, 
      "img_src" : "http://www.xyz.com/manuals/particleblaster5000.jpg", 
      "description" : "A laser cutter used in plastic manufacturing." 
   } 
}

The next step is to place the file in the directory used by your apppcation.

Java primarily uses the putItem and path methods to perform the load.

You can review the following code example for processing a file and loading it −

import java.io.File;
import java.util.Iterator;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDBCpent;
import com.amazonaws.services.dynamodbv2.document.DynamoDB;
import com.amazonaws.services.dynamodbv2.document.Item;
import com.amazonaws.services.dynamodbv2.document.Table;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.databind.node.ObjectNode;

pubpc class ProductsLoadData {  
   pubpc static void main(String[] args) throws Exception {  
      AmazonDynamoDBCpent cpent = new AmazonDynamoDBCpent() 
         .withEndpoint("http://localhost:8000");  
      
      DynamoDB dynamoDB = new DynamoDB(cpent);  
      Table table = dynamoDB.getTable("Products");  
      JsonParser parser = new JsonFactory() 
         .createParser(new File("productinfo.json"));  
      
      JsonNode rootNode = new ObjectMapper().readTree(parser); 
      Iterator<JsonNode> iter = rootNode.iterator();  
      ObjectNode currentNode;  
      
      while (iter.hasNext()) { 
         currentNode = (ObjectNode) iter.next();  
         int ID = currentNode.path("ID").asInt(); 
         String Nomenclature = currentNode.path("Nomenclature").asText();  
         
         try { 
            table.putItem(new Item() 
               .withPrimaryKey("ID", ID, "Nomenclature", Nomenclature) 
               .withJSON("Stat", currentNode.path("Stat").toString()));
            System.out.println("Successful load: " + ID + " " + Nomenclature);  
         } catch (Exception e) {
            System.err.println("Cannot add product: " + ID + " " + Nomenclature);
            System.err.println(e.getMessage()); 
            break; 
         } 
      } 
      parser.close(); 
   } 
}