HttpRequest Class in Salesforce for generating HttpRequest

Use the HttpRequest class to programmatically create HTTP requests like GET, POST, PUT, and DELETE.

Use the DOM Classes  or Json Classes to Parse XML or JSON content in the body of a request created by HttpRequest.

Methods:

The HttpRequest class contains the following public methods:

Name	Arguments	Return Type	Description
getBody		String	Retrieves the body of this request.
getBodyAsBlob		Blob	Retrieves the body of this request as a Blob.
getBodyDocument		Dom.Document	Retrieves the body of this request as a DOM document. Use it as a shortcut for: String xml = httpRequest.getBody(); Dom.Document domDoc = new Dom.Document(xml);
getCompressed		Boolean	If true, the request body is compressed, false otherwise.
getEndpoint		String	Retrieves the URL for the endpoint of the external server for this request.
getHeader	String key	String	Retrieves the contents of the request header.
getMethod		String	Returns the type of method used by HttpRequest. For example: DELETE GET HEAD POST PUT TRACE
setBody	String body	Void	Sets the contents of the body for this request. Limit: 3 MB. The HTTP request and response sizes count towards the total heap size.
setBodyAsBlob	Blob body	Void	Sets the contents of the body for this request using a Blob. Limit: 3 MB. The HTTP request and response sizes count towards the total heap size.
setBodyDocument	Dom.Document document	Void	Sets the contents of the body for this request. The contents represent a DOM document. Limit: 3 MB.
setClientCertificate	String clientCert String password	Void	This method is deprecated. Use setClientCertificateName instead. If the server requires a client certificate for authentication, set the client certificate PKCS12 key store and password.
setClientCertificateName	String certDevName	Void	If the external service requires a client certificate for authentication, set the certificate name. See Using Certificates with HTTP Requests.
setCompressed	Boolean flag	Void	If true, the data in the body is delivered to the endpoint in the gzip compressed format. If false, no compression format is used.
setEndpoint	String endpoint	Void	Sets the URL for the endpoint of the external server for this request.
setHeader	String key String Value	Void	Sets the contents of the request header. Limit 100 KB.
setMethod	String method		Sets the type of method to be used for the HTTP request. For example: DELETE GET HEAD POST PUT TRACE You can also use this method to set any required options.
setTimeout	Integer timeout	Void	Sets the timeout in milliseconds for the request. This can be any value between 1 and 120,000 milliseconds.
toString		String	Returns a string containing the URL for the endpoint of the external server for this request and the method used, for example, Endpoint=http://YourServer, Method=POST

The following example illustrates how you can use an authorization header with a request, and handle the response:

Example:

public class AuthCallout 
{ 
  public void basicAuthCallout()
  {  
    HttpRequest req = new HttpRequest();
    req.setEndpoint('http://www.yahoo.com');
    req.setMethod('GET');

    // Specify the required user name and password to access the endpoint
    // As well as the header and header information
     String username = 'myname';
     String password = 'mypwd';
  
     Blob headerValue = Blob.valueOf(username + ':' + password);
     String authorizationHeader = 'BASIC ' +
     EncodingUtil.base64Encode(headerValue);
     req.setHeader('Authorization', authorizationHeader);
   
    // Create a new http object to send the request object
    // A response object is generated as a result of the request  
  
     Http http = new Http();
     HTTPResponse res = http.send(req);
     System.debug(res.getBody());
   }
}

Compression

If you need to compress the data you send, use setCompressed, as the following sample illustrates:

HttpRequest req = new HttpRequest();
req.setEndPoint('my_endpoint');
req.setCompressed(true);
req.setBody('some post body');

If a response comes back in compressed format, getBody automatically recognizes the format, uncompresses it, and returns the uncompressed value.