How to Obtain an InputStream Using RestTemplate Instead of URL in Java?

How can I get InputStream with RestTemplate instead of using URL?

InputStream input = new URL(url).openStream();  
JsonReader reader = new JsonReader(new InputStreamReader(input, StandardCharsets.UTF_8.displayName()));

In Java, the RestTemplate class, part of the Spring Framework, is a powerful tool for making RESTful HTTP calls. Unlike using the URL class directly to obtain an InputStream, RestTemplate allows you to easily handle HTTP requests and responses, making the code cleaner and more maintainable.

RestTemplate restTemplate = new RestTemplate();  
ResponseEntity<InputStream> responseEntity = restTemplate.exchange(url, HttpMethod.GET, null, InputStream.class);  
InputStream inputStream = responseEntity.getBody();  
JsonReader reader = new JsonReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));

Causes

• Need for more flexibility and error handling in HTTP requests.
• Desire to simplify processing of JSON responses from RESTful services.

Solutions

• Utilize RestTemplate's exchange method to make a GET request that returns an InputStream.
• Configure the RestTemplate to read the response as a stream.

Mistake: Not handling the InputStream properly which may lead to resource leaks.

Solution: Always close the InputStream in a finally block or use try-with-resources for automatic management.

Mistake: Ignoring HTTP errors while trying to obtain the InputStream, leading to exceptions.

Solution: Check the response status code, and handle errors accordingly, possibly using RestTemplate's ResponseErrorHandler.