HTTP Classes

These classes expose the general HTTP request/response functionality:

Http Class. Use this class to initiate an HTTP request and response.
HttpRequest Class: Use this class to programmatically create HTTP requests like GET, POST, PUT, and DELETE.
HttpResponse Class: Use this class to handle the HTTP response returned by HTTP.

The HttpRequest and HttpResponse classes support the following elements:

HttpRequest:
- HTTP request types such as GET, POST, PUT, DELETE, TRACE, CONNECT, HEAD, and OPTIONS.
- Request headers if needed.
- Read and connection timeouts.
- Redirects if needed.
- Content of the message body.
HttpResponse:
- The HTTP status code.
- Response headers if needed.
- Content of the response body.

The following example shows an HTTP GET request made to the external server specified by the value of url that gets passed into the getContent method. This example also shows accessing the body of the returned response:

public class HttpCalloutSample {

// Pass in the endpoint to be used using the string url  
    
  public String getContent(String url) {

// Instantiate a new http object  
    
    Http h = new Http();

// Instantiate a new HTTP request, specify the method (GET) as well as the endpoint  
    
    HttpRequest req = new HttpRequest();
    req.setEndpoint(url);
    req.setMethod('GET');

// Send the request, and return a response  
    
    HttpResponse res = h.send(req);
    return res.getBody();
  }
}

Before you can access external servers from an endpoint or redirect endpoint using Apex or any other feature, you must add the remote site to a list of authorized remote sites in the Salesforce.com user interface. To do this, log in to Salesforce.com and select Setup | Security Controls | Remote Proxy Settings.

Note

The AJAX proxy handles redirects and authentication challenges (401/407 responses) automatically. For more information about the AJAX proxy, see AJAX Toolkit documentation.

Use the DOM Classes to parse XML content in the body of a request created by HttpRequest or a response accessed by HttpResponse.