REST Service Application

The REST Application allows to invoke REST Services with Process Data and retrieve data from the response of the REST services into Process Data.

You can perform following operations on a REST Service Application.

• Viewing and Editing Properties
  • Parameters
  • Test
  • Configuration
  • Security
  • Comments
• Proxy Configuration

Viewing and Editing Properties

Following properties should be specified:

Figure: Properties - REST Service Application

• UUID - A unique identifier ID gets generated as an identifier for client server communication
• ID - An ID generated automatically based on the application name. If element with the same name exists then during ID generation, a numerical suffix gets added to the ID. If the element is renamed, the ID gets regenerated.

The UUID and ID options are displayed only when you switch to Integrator profile.

• Application Name - Specify name of the application
• Description - Specify the description
• Public Visibility - By default, this check box is selected. It indicates that the element is visible and available for reference from any other model.

Parameters

You can define parameters to access the data associated with the application. The REST Application only allows for zero or one Output Parameter which is representing the HTTP Response content of the REST Service invocation. It allows for multiple Input Parameters. One Input Parameter can be selected to be transferred in the body of the HTTP Request of the REST Service invocation. All other Input Parameters are expected to be provided in the header and hence have to be primitive data. Click the Add icon to add the parameters.

• Body Input Access Point - By default None is selected. When you select Body Input access point then the data value will be in the body of the exchange. All other IN access points will be set to the header of the exchange.
• Body Output Access Point - By default None is selected. When you select Body Output access point then the data value will be in the body of the exchange. All other OUT access points will be set to the header of the exchange.
• Name - Specify name for the new parameter
• Direction - Select direction for the data from the Direction drop-down list. If at least one out mapping is provided then application is considered send/receive. If no out mapping provided the application is considered as send only. Following options are provided:
  • In - For read access. If an IN access point is used in the request URL it should not be defined as Body Input Access Point.
  • Out - For write access
• Data Type - Following data types are supported:
  • Primitive - If you select Primitive data type, you need to provide Primitive Type.
  • Structured Data - If you select structured data, you need to provide Structure Type. It also lists structured types from other models.

To delete the parameters, select the added parameter and click the Delete icon.

Test

• Reinitialize Input Data Fields - Input generates a string representation top-level JSON object with all Input Parameters as fields. The objects underneath these fields represent empty structures or primitive literals of the data types of the Input Parameters. For arrays, one entry is created.
• Reinitialize External Web Application - Invoking the test performs the REST call and displays a string value of the body of the HTTP response of the REST Service.

Figure: Properties - Test

Configuration

Figure: Properties - Configuration

• URI - Specify the URI of REST web services. If you don't specify using place holders anywhere in your URL, IN access point get appended as URL parameter. However, as soon as you use a place holder for a certain IN access point in your URL, the concrete value should end up where you have specified it. For example, in the following URL: localhost://RestService.vcs/GetRestData/{id} Should replace the place holder {id} with the value for IN access point id at runtime.
• Query String - Based on input parameters, the query string gets formed and displayed. The formed string automatically gets appended to the URI for REST call. Each IN access point will be appended as URL parameter with two exceptions:
  • There is an explicit place holder for it. In that case the place holder will be replaced by the actual value at runtime.
  • The IN access point has been defined as Body Input Access Point. In that case it will be handled as payload for a POST request.
• Command - By default, GET is selected. You can select following options as request methods:
  • GET
  • POST
  • PUT
  • DELETE
• Request Type - By default, None is selected. You can select the following request types based on the type of web service:
  • Text
  • HTML
  • XML
  • JSON
• Response Type - By default, HTML is selected. You can select following types based on the response returned by web service.
  • HTML
  • XML
  • JSON
• Allow Cross Domain Call - Select this checkbox to allow a web page to make XMLHttpRequests to another domain. For more information, please refer to the Cross-origin resource sharing.

Security

Based on the security mode you need to specify the details. For more information please refer to chapter Security Propagation for Web Applications of the Concepts Security Propagation for Web Applications in the Concepts handbook. The following options are provided in the Security Mode drop down list:

• None
• Basic HTTP Authentication
• Custom Security Token

Basic HTTP Basic Authentication

Figure: Basic HTTP Basic Authentication

• Username - Specify the user name
• Password - Specify the configuration variable
• Use Configuration Variable for Password - We recommend you to select this checkbox if you want to use configuration variable for Password field. If you select this checkbox, then in the model properties, the configuration variable of type Password is created automatically. However, do not specify the default value for it in model properties itself.

  
  Figure: Configuration Variable - Password Type

  Specify the value of type password in the Configuration Variable view of the Administration perspective after deployment.
• Authentication Preemptive - Specify whether the authentication should be attempted preemptively.

Custom Security Token

Figure: Custom Security Token

The key/value pair gets added to the header of the HTTP request.

• Token Key - Specify the token key to be passed to the HTTP header
• Token Value - Specify the configuration variable
• Use Configuration Variable for Token - We recommend you to select this checkbox if you want to use configuration variable for Password field. If you select this checkbox, then in the model properties, the configuration variable of type Password is created automatically. However, do not specify the default value for it in model properties itself.

  
  Figure: Configuration Variable - Password Type

• HTTP Headers
  • Name - Specify the name to be passed to HTTP header
  • Value - Specify the value to be passed to HTTP header

You can add and delete the rows in the HTTP headers table.

Comments

Click the Comments tab to add comments for the application. To add the comment, specify the comment in the text box and click Submit. The newest comment gets displayed at the top of the table. To delete the comment, select the comment and click the Delete icon. The user, who has submitted the comment, can delete that comment. If the other user selects the comment or no comment is selected, the Delete icon remains in disabled state.

Figure: Comments

Proxy Configuration

However, note that you may need to add proxy settings to access the service. To do the proxy settings, add the following bean in the context file or any Spring configuration file.

<bean id="httpConfiguration" class="org.apache.camel.component.http.HttpConfiguration">
<property name="proxyHost" value="<yourhostname>"/>
<property name="proxyPort" value="<yourportname>" />
</bean>
<bean id="http" class="org.apache.camel.component.http.HttpComponent">
<property name="camelContext" ref="defaultCamelContext" />
<property name="httpConfiguration" ref="httpConfiguration" />
</bean>