JPostman

A Java wrapper for Postman collection files.

Docs

Postman Collection Overview

Postman Collection SDK (Node)

Getting started

1. Download the JAR file from the releases tab
2. Import com.postman.collection.Collection in your source code.
3. Instantiate a new collection by passing the path to a Postman collection .json file to the Collection.pmcFactory method

Collection pmcTest = Collection.pmcFactory("/path/to/your/exported/collection.json");

What you can do

Integrate with Java applications and platforms

Java is common in Enterprise software development environments. JPostman enables you to create a complete Java object model of a Postman collection from an exported collection JSON file. This provides a bridge for integrating with Java based applications and platforms such as JMeter.

Create collections from exported postman_collection.json files

  File jsonFile = new File("/path/to/your/exported/collection.json");
  Collection pmcTest = Collection.pmcFactory(jsonFile);

You can experiment with example collections in the Resources folder.

Import a collection directly from Postman

Got a Collection ID and a Postman API Key? Create Collection object directly from Postman:

Collection pmcTest = Collection.pmcFactory(new PostmanID("<your collection id>"));

NOTE: You must set an environment variable named POSTMAN_API_KEY with the value of your Postman API key.

Create Collections from scratch

You can create a new, empty collection as well

Collection newColl = Collection.pmcFactory();
newColl.setName("My new collection");

then create and add elements to your new collection

Add requests

You can add a new request just by providing a URL:

  Collection newColl = Collection.pmcFactory();
  newColl.addRequest("https://postman-echo.com/get");

Edit collections: add, remove, edit and move Collection elements

JPostman allows you to add new Folders and Requests to your Postman Collections. You can also add variables, Pre-Request and Test Scripts, requests, and responses. In fact, you can add, edit, or remove any element in a Postman collection. All add operations allow you to specify a position in the array of items on the object, meaning that you preserve the order of Folders, Requests, etc, in the collection.

For example, adding a new Folder as the third item in the collection:

 // Add a new folder to the 3rd position beneath the root of the collection
  Collection pmcTest = Collection.pmcFactory("/path/to/your/exported/collection.json");
  Folder newFolder = new Folder("new Folder");
  pmcTest.addFolder(newFolder, 2);
  

Move collection elements

You can easily move elements from one parent to another. For example, move a request to a new folder, or a folder to another folder or to the top level in the collection.

  Collection pmcTest = Collection.pmcFactory("/path/to/your/exported/collection.json");
  Item newFolder1 = new Folder("new Folder One");
  Item newFolder2 = new Folder("new Folder Two");
  pmcTest.addFolder(newFolder1);
  pmcTest.addFolder(newFolder2);
  pmcTest.moveItem(newFolder2, newFolder1);

Combining collections

You can combine collections as well.

// Combine collections, inserting the source collection as a Folder in the 2d position from the root of the target collection
Collection pmcTarget = Collection.pmcFactory("/path/to/your/exported/collection.json");
Collection pmcSource = Collection.pmcFactory("/path/to/another/collection.json");
pmcTest.addCollection(pmcSource);

When a collection is added, a new Folder is created and all of the added collection's elements are linked to that folder. The folder in turn is then linked to the target collection. All folders, requests, pre-request and test scripts are copied over from the source to the target collection. Collection variables are appended to the target collections array of variables.

There are options for copying (or not copying) the source collections scripts and variables as well. You can also specify a specific parent to receive the source collection.

Write your edited collections to a JSON file

JPostman allows you to generate JSON for your collections. You can also write your collections to a file which can then be imported into Postman.

  // Combine collections, inserting the source collection as a Folder in the 2d position from the root of the target collection
  // Then set the value of a String variable to the JSON for the new, combined collection.  
  Collection pmcTarget = Collection.pmcFactory("/path/to/your/exported/collection.json");
  Collection pmcSource = Collection.pmcFactory("/path/to/another/collection.json");
  pmcTest.addCollection(pmcSource);
  pmcTest.writeToFile("new-collection.json");

Create or update a collection in Postman

You can upsert (create or update) a collection in Postman, optionally adding it to a workspace.

• If a collection does not have a collection ID, it will be created on Postman, and given the UUID returned by Postman
• You can optionally include a workspace ID to link the newly created collection to that workspace

  pmcTest.upsertToPostman(new PostmanID(<POSTMAN_WORKSPACE_ID>"));

• If a collection has a collection ID, it will be updated in Postman.

Validate collections (and any collection element) against the Postman Collection Schema

Use the `Collection.validate() method to ensure that the JSON emitted by your instance of Collection conforms with the Postman Collection schema:

 boolean isValid = myCollection.validate();

JPostman uses the NetworkNT json-schema-validator to validate JSON against a JSON schema.

If the validate() method returns false, call getValidationMessages() for an array of ValidationMessage objects describing differences between your collections generated JSON and the Postman schema.

Individual Elements

Since collections and the elements they contain all extend the CollectionElement class they have the potential to be individually validated as well. Currently, element validation is supported for:

• Collection
• Item
• RequestAuth
• BodyElement

Implementation

Java does not natively support JSON in the way that NodeJS does. Object models based on JSON must be manually constructed. Forutnately the brilliant folks at Google came up with GSON a library that does this automatically. Basically you create Java classes with member variables that match the keys in the JSON file. GSON then parses the file and builds out the object model. GSON also allows for an object model to be written out to JSON.

GSON does not link parents to their child objects, so deriving parent objects is not straightforward. In this implementation we recurse the object tree until we find the object which contains the target object, and return that as the parent.

GSON also works with arrays by default rather than more convenient Java collections mechanisms like Collections, Maps, etc. This has the advantage of simplicity but does make adding, removing, or re-ordering collection elements somewhat more complex and onerous.

Postman Collection File Structure

You can review the schema for the Postman Collection v2.1 format here. The Postman team have provided a comprehensive overview of the Collection format here

In a nutshell, a Postman collection file consists of the following elements

1. An info section containing collection metadata, including it's name, description, and Postman UID
2. Zero or more item elements, which can themselves contain an array if item elements. There are two types of item objects

• A Request is an item that contains a request key. These are rendered in Postman as Requests. Request items do not contain sub-items, they are always leaf elements.
• A folder is an item that contains zero or more sub-items, but which does NOT contain a request key.

3. Pre-Request and Test scripts are stored in an event key. Any item can have an event key.
4. Collection variables are stored under the variables key.

Thus, a collection is info, variables, events, and an arry if items, each of which can contain any number of sub-items.