Remedy AR System API architecture

This topic discusses the architectures of APIs that Remedy AR System employs:

Plug-in API—Extends the Remedy AR System server to integrate with external data sources
C and Java API—Creates an interface layer between the Remedy AR System server and C-based and Java-based Remedy AR System clients
REST API—A web service that conforms to the architectural principles of Representational State Transfer (REST)

Remedy AR System plug-in API architecture

Remedy AR System clients perform external data source operations on external forms through the Remedy AR System server, plug-in service, and plug-in APIs. The plug-in service extends the Remedy AR System server to integrate with external data sources. The Remedy AR System server connects to the plug-in service, which activates the plug-ins.

Plug-in architecture

Note

The arrows in this figure identify the directions in which each program or process can initiate API function calls. Data can flow in any direction.

Remedy AR System client code links to the provided C API libraries. The C APIs create an interface layer between the Remedy AR System server and C-based Remedy AR System clients. The Java API serves the same function for Java-based clients. Remedy AR System clients perform all database operations through the API interface.

Remedy AR System includes a plug-in server that extends its functionality to external data (data not contained in the Remedy AR System database). The plug-in service supports three types of plug-ins with corresponding C and Java APIs:

AREA plug-in
ARDBC plug-in
Remedy AR System Filter (AR Filter) API plug-in

Remedy AR System offers the following ready-to-use plug-ins that you access through Remedy Developer Studio:

Remedy AR System External Authentication (AREA) Lightweight Directory Access Protocol (LDAP) plug-in
Remedy AR System Database Connectivity (ARDBC) LDAP plug-in

Both plug-ins access LDAP services.

For information about the C plug-in APIs, see Remedy AR System plug-in API functions. For information about the Java Plug-in API, see the online documentation located at ARSystemServerInstallDir\ARserver\api\javaplugins\arpluginsdocVerNum.jar.

For information about configuring and running all types of plug-ins, see Enabling Plug-ins.

Remedy AR System C and Java API architecture

Note

The arrows in the preceding figure identify the directions in which each program or process can initiate API function calls. Data can flow in all directions.

Important

The Java API also uses a Java Native Interface (JNI) library and the C API library to connect to a pre-7.0.01 Remedy AR System server. You can control when the JNI library is used by setting the jniLoadMode parameter in the Java API configuration file. See the comments in the sample file, arsys_sample.xml.

C API

The Remedy AR System clients use the C APIs to manipulate data. For example, the clients use C APIs to create, retrieve, update, and delete schemas, entries, and menus, and to control workflow. You can use the C API to extend Remedy AR System functionality.

The Remedy AR System API contains data structures that store simple and complex information. Structures that store simple information (such as the type of value or the product of an arithmetic operation) serve as the building blocks for complex structures.

You can run API programs by using the following methods:

From a command line
From the Remedy AR System
- In the Set Field $PROCESS$ action from an active link, filter, or escalation
- With the Run Process action in an active link, filter, or escalation

The C APIs consist of a set of functions, most of which cause the server to perform a specific database or data source operation and return a result. For example, you can create an entry or retrieve information about a particular Remedy AR System object. Remedy AR System C API functions describes the purpose and use of each Remedy AR System C API function. Remedy AR System plug-in API functions describes the purpose and use of the common Remedy AR System, AREA, ARDBC, and Remedy AR filter API plug-in functions.

In addition, almost all of the Remedy AR System C API functions accept one or more structure-type parameters. Data structures explains some of the most common structures and the operations they apply to. The ar.h file defines the types. If you understand the functions and structures that comprise the API, you can interact with the Remedy AR System server to customize and extend your applications.

The driver directory contains source code for the driver program. This program provides a command-line interface for calling Remedy AR System C API functions. The driver program also includes print routines for every data structure in the API, making it a useful debugging tool. See Using the driver program for additional information about this topic.

Java API

The Remedy AR System Java API is a collection of Java classes that provide the full Remedy AR System API functionality in a Java development environment. The Java API:

Provides an object model of Remedy AR System server entities (also called server objects), definitions, and data.
Includes a single class, ARServerUser, that provides the context and the methods required to interact with the Remedy AR System server.

The JavaDriver directory contains source code for a Java program like the C driver program.

Use the Remedy AR System Java API to perform the following tasks:

Write server-side web applications that you access through the Java server page (JSP) or Java servlets web tier layer
Implement Remedy AR System clients in Java

For more information about the Java API, see Remedy AR System Java API overview and the Java API documentation HTML files in the ardocVerNum.jar file in the \Arserver\Api\doc folder (Windows) or the /ARServer/api/doc folder (UNIX). To access the Java API documentation, unzip the ardocVerNum.jar file to create a tree of directories, then open the index.html file.

Comparison of the Java and C APIs

The Remedy AR System Java and C APIs have a number of differences, for example:

The Java Virtual Machine (JVM) uses garbage collecting functions to automatically deallocate objects that are created with the Java API. The C API includes a set of memory deallocating functions that you can use to deallocate memory.
In the C API, the control parameter provides server access information with every call. In the Java API, the ARServerUser object encapsulates this information.
The C API and Java API have different naming conventions.

Remedy AR System REST API architecture

The API is a web service that conforms to the architectural principles of Representational State Transfer (REST). Each API is called by issuing a standard HTTP request method: POST, GET, PUT, or DELETE (more commonly known as the CRUD operations: Create, Read, Update, and Delete). The REST API is a simple stateless architecture that runs over the HTTP. The advantage of REST is having a limited number of operations for the interactions between clients and services.

The REST API uses the base URI for the web service, such as https://<localhost>:<port>/api/{namespace}/{version}

api - is the default prefix.

namespace - is used to help separate the different APIs.

version - is the version used for particular REST API.

For more information about the REST API, see Integrating-AR-System-forms-with-a-third-party-application-by-using-the-REST-API.