How do I get JSON from the server? [Java Code]

To request JSON from a URL using Java, you need to send an HTTP GET request to the server and provide the Accept: application/json request header with your request. The Accept header tells the server that our Java client is expecting JSON. The server informs the Java client that it has returned JSON with a Content-Type: application/json response header. In this Java request JSON example, we are making a GET request to the ReqBin echo URL. The Java code was automatically generated for the GET JSON example.
How do I get JSON from the server? [Java Code] Send
GET /echo/get/json HTTP/1.1
Host: reqbin.com
Accept: application/json

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Java code for GET JSON example

Java code for GET JSON Example

This Java code snippet was generated automatically for the GET JSON example.
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What it JSON?

JavaScript Object Notation (JSON) is a lightweight text-based, language-independent data exchange format. JSON defines a small set of formatting rules for the portable representation of structured data. JSON can represent four primitive types (strings, numbers, boolean values, and null) and two structured types (objects and arrays). JSON is used to exchange data between applications written in many programming languages, including JavaScript, Java, C++, C#, Go, PHP, Python, and many others.

How to request data in JSON format using Java?

To get data in JSON format from the server, the Java client must explicitly tell the server that it expects JSON by sending the Accept: application/json request header. Without the Accept header, the server may automatically send data in a different format that it thinks is best for the API client (based on the UserAgent header), and it might not be JSON.

JSON Accept Header Example
Accept: application/json

How to send and receive JSON data using JavaScript?

JSON data is transmitted over the network as a text string and must be converted to a JavaScript object before using it. Likewise, before sending JavaScript objects over the network in JSON format, they must be converted to strings. JavaScript has two built-in functions for converting JavaScript objects to JSON and vice versa:

  • JSON.parse() - converts a JSON string to a JavaScript object.
  • JSON.stringify() - converts a JavaScript object to a JSON string.

Java JSON Request Example

An example of an HTTP GET request to fetch JSON data from a ReqBin echo URL. Click Generate Code to see the Java code for this JSON request example.

JSON Request Example
GET /echo/get/json HTTP/1.1
Host: reqbin.com
Accept: application/json

The server response to our Java client's request.

JSON Response Example
HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: 19

{"success":"true"}

The server returned JSON in the body of the HTTP response message. The Content-Length: 19 header indicates the length of the JSON data in the response body, and the Content-Type: application/json response header indicates the type of data.

JSON MIME Type

The official MIME type for JSON is application/json:

JSON Content-Type Header Example
Content-Type: application/json

See also

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