How to Batch Multiple Requests Through DWR Servlets

Do you have many request that need to be sent to the server at once? Batching multiple requests through DWR Servlets can save you vast amounts of time and resources. This document will show you how to batch multiple requests using DWR Servlets and also answer some of the FAQs regarding this process.

Step 1: Set Up DWR Servlet

In order for you to be able to batch multiple requests, you will need to set up the DWR Servlet. This servlet acts as the bridge between your server and the web browser, allowing it to execute requests and retrieve a response.

To set up the servlet, you will have to add the following section to your web.xml file:

<servlet>
  <servlet-name>dwr-invoker</servlet-name>
  <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>dwr-invoker</servlet-name>
  <url-pattern>/dwr/*</url-pattern>
</servlet-mapping>

Once you do that, the server will be able to use DWR Servlets for batching requests.

Step 2: Create a New Batched Request

Now that you have completed the setup, you can begin creating batch request. The first step is to create a request object. The request object should include a data object, which will contain the parameters and the data that you need to send to the server.

For example:

var data = {
    "name": "Mark",
    "email": "[email protected]"
};

var request = {
    url: "/users/save",
    method: "POST",
    data: data
};

Step 3: Create the Batch Assembler

Once your request is created, you will have to create the batch assembler. This assembler will be responsible for collecting, organizing and sending multiple requests to the server in a batch.

For example:

// Create a new 
var batch = DWR.util.createBatch();

// Attach the request to the batch 
batch.addRequest({
    url: "/users/save",
    method: "POST",
    data: data
});

// Send the batch to the server 
batch.send();

When you send the batch to the server, it will process your requests and send back a response containing the status of each request. If you need to send multiple requests in a single batch, then you will have to add them to the batch in the same way as described above.

Step 4: Handle the Response

Finally, when the server has finished processing the batch, it will send back a response in a JSON format. This response will contain the status of each request (e.g. success or failure) as well as any additional information that is relevant to the request.

You can then use this response to check the status of each request and make sure that it was processed successfully.

FAQ

How Do I Batch Multiple Requests?

Batching multiple requests is a simple process that involves setting up a DWR Servlet, creating a request object, creating a batch assembler and handling the response from the server. These steps are explained in detail in the sections above.

Can I Send Large Amounts of Data with a Batch Request?

Yes, you can. You just need to make sure that the data does not exceed the maximum size limit for a batch request, which is usually 2MB.

Is Batching Requests Faster Than Sending them Individually?

Yes, it is. Batching multiple requests can reduce the time and resources required for sending and receiving multiple requests, as the server only needs to handle one request instead of multiple requests.

Does a Batch Request Return an Array of Responses?

No, a batch request does not return an array of responses. Instead, it returns a single response in a JSON format, which contains the status of each request.

What Is the Maximum Size Limit for a Batch Request?

The maximum size limit for a batch request is usually 2MB. If you need to send larger amounts of data, then it is better to break the data into multiple batches.