Test APIs by Postman

In this step, we will test the three APIs we deployed — GET, POST, and DELETE — using Postman.

Make sure you have the Invoke URLs saved from the previous steps:

• GET / POST: https://<api-id>.execute-api.ap-southeast-1.amazonaws.com/staging/books
• DELETE: https://<api-id>.execute-api.ap-southeast-1.amazonaws.com/staging/books/{id}

Test the GET API (List books)

1. Open Postman. Click + to open a new tab.

   • Select the GET method.
   • Enter the Invoke URL for the listing API saved from section 4.2.
   • Click Send.

   The response body returns a JSON array containing all items from the Books DynamoDB table, including book details, image URLs, and comments. The status code is 200 OK.

   

Test the POST API (Create a book)

2. Click + to open a new tab.

   • Select the POST method.

   • Enter the Invoke URL for the writing API saved from section 4.3.

   • Click the Body tab, then select form-data.

   • Fill in the following key-value pairs. For the image key, change its type dropdown from Text to File, then select a local image file from your machine.

   • Download the image aws-logo.png at Link and select this image file.

     Key	Type	Value
     name	Text	Amazon Web Services in Action 2nd Edition
     author	Text	Andreas Wittig
     price	Text	59.99
     category	Text	IT
     description	Text	Amazon Web Services in Action, Second Edition is a comprehensive introduction to computing, storing, and networking in the AWS cloud.
     image	File	(select a local image file, e.g., aws-logo.png)

   • Click Send. The response body returns “Successfully created item!” with status 200 OK.

   

3. Open DynamoDB console.

   • Click Explore items → select the Books table → click Run.
   • Confirm that the new item (e.g., id = 5, author = Andreas Wittig) appears in the table. The total item count should have increased by 1 (now 10 items).

   

Test the DELETE API (Delete a book)

4. Click + to open a new tab.

   • Select the DELETE method.
   • Enter the Invoke URL for the DELETE API saved from section 4.4. Replace {id} with the ID of the book you just created, e.g., 5:

     https://<api-id>.execute-api.ap-southeast-1.amazonaws.com/staging/books/5
     

   • Click Send. The response body returns “Successfully delete item!” with status 200 OK.

   

5. Return to DynamoDB console → Explore items → Books table → click Run again.

   • Confirm the item with id = 5 is no longer present. The total item count should have decreased by 1 (now 9 items).

   

6. Open Amazon S3 console and navigate to the book-image-resize-shop-by-tranvix bucket.

   • Confirm that the uploaded image file (aws-logo.png) has been removed. The bucket should show Objects (0).