Apex Developer Guide

Apex Developer Guide
Release Notes
Getting Started with Apex
Writing Apex
Running Apex
Invoking Apex
Apex Transactions and Governor Limits
Using Salesforce Features with Apex
Integration and Apex Utilities
Invoking Callouts Using Apex
Adding Remote Site Settings
Named Credentials as Callout Endpoints
SOAP Services: Defining a Class from a WSDL Document
Invoking HTTP Callouts
Using Certificates
Callout Limits and Limitations
Make Long-Running Callouts with Continuations
JSON Support
XML Support
ZIP Support
Securing Your Data
Encoding Your Data
Using Patterns and Matchers
Debugging, Testing, and Deploying Apex
Apex Reference
Appendices
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Invoking Callouts Using Apex

An Apex callout enables you to tightly integrate your Apex with an external service by making a call to an external Web service or sending a HTTP request from Apex code and then receiving the response. Apex provides integration with Web services that utilize SOAP and WSDL, or HTTP services (RESTful services).

Before any Apex callout can call an external site, that site must be registered in the Remote Site Settings page, or the callout fails. Salesforce prevents calls to unauthorized network addresses.

If the callout specifies a named credential as the endpoint, you don’t need to configure remote site settings. A named credential specifies the URL of a callout endpoint and its required authentication parameters in one definition. To set up named credentials, see “Define a Named Credential” in the Salesforce Help.

Note

To learn more about the types of callouts, see:

Callouts enable Apex to invoke external web or HTTP services. Apex Web services allow an external application to invoke Apex methods through Web services.

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