Creating JCo Destinations 

Use

If you choose Create JCo destination in the Web Dynpro Content Administrator, a wizard opens with which you can define a new JCo destination.

You can find details about the SAP Java Connector in the SAP Library under SAP NetWeaver ®  Application Platform (SAP Web Application Server) ® Connectivity ® Components of SAP Communications Technology ® Communications Between ABAP and Non-ABAP Technologies ® SAP Java Connector.

If you are using an adaptive RFC model in a Web Dynpro application, you must define two JCo destinations:

·        The application gets metadata from the first connection. When defining  JCo destinations for metadata, you may only use authentication method User/Password. For further information, see Point 5 in the procedure.

·        The application gets the application data from the second destination.

Prerequisites

You have administrator authorization for the J2EE Engine and access to a System Landscape Directory (SLD).

Procedure

You can either copy the data needed for a JCo destination from an existing destination by selecting the checkbox in the first step of the wizard or define it as follows in the wizard steps:

...

       1.      Define general data
Define a logical name for the JCo destination. This name must be unique and you should choose a self-explanatory name. In addition, you can define the client.
You can also specify the configuration of the JCo pool for a JCo destination in the left group. At runtime, the JCo connection is implemented with a pool. This pool is a set of client connections for a specific JCo destinations. The pool can automatically generate new connections for an SAP system and provides methods to return the connections to the pool if they are not needed any more. It also checks periodically which connections are no longer used by the application and can therefore be closed.
To minimize the use of resources, you can define the maximum number of connections that can be contained in a pool by using the option Maximum Pool Size. The pool keeps as many JCo connections open as you defined for the maximum pool size and these connections do not have to be newly created. You can reuse these connections any time. The JCo pool can, however, contain more connections than you defined for the Maximum Pool Size. This number of connections is specified by the option Maximum Connections. This is the maximum number of connections that can be set up at runtime.
If the number of Maximum Connections is higher than the number of Maximum Pool Size, the JCo connections that are not needed are immediately closed.
If the application needs more connections than defined for Maximum Connections, the required connections are sent to a queue and can only be opened when other JCo connections are closed.
For more information about JCo pool, refer to the SAP Library under SAP NetWeaver  ® Application Platform (SAP Web Application Server) ® Connectivity  ® Components of SAP Communication Technology  ® Communication Between ABAP and Non-ABAP Technologies ® SAP Java Connector ® SAP JCo Client Programming ® Establishing Connection to an SAP Server ® Connection Pools, or refer to the help of the SAP NetWeawer Developer Studio for the description of the class JCO.Pool under SAP NetWeaver Developer Studio Documentation ® SAP Web AS for Java Applications ® API WAS ® Java Connector ® com.sap.mw.jco ® JCO.Pool.

¡        Maximum Pool Size
Specifies the maximum number of open connections stored in the pool. They can be immediately used by the application.

¡        Maximum Connections
Specifies the maximum number of connections available in the pool. They can be generated at runtime. If all connections are used and the capacity of the pool is exhausted, the next requested connection is sent to a queue until another connection is closed. The duration of the waiting time in the queue is specifed by the option Maximum Waiting Time. If no connection is closed during this waiting time, an error message appears.If the number of Maximum Connections is higher than the number of Maximum Pool Size, the JCo connections that are not needed are immediately closed.

¡        Connection Timeout (sec.)
Specifies the time after which an opened connection that is not needed is closed.

¡        Maximum Waiting Time (sec.)
Specifies the maximum time to open a connection in the pool when the capacity of the pool is exhausted.

       2.      Define the J2EE cluster
Assign the JCo destination to a J2EE Engine cluster. A cluster is a distributed system of the J2EE Engine dispatcher and other server elements that appear to the client as a unit.
The default is the locally installed J2EE Engine and it is labeled Use local J2EE Engine.

       3.      Define the data type and connection type

In this step you select the data type for the JCo destination. You can choose one of the following values in the radio button group

¡        Dictionary metadata

¡        Application data

You then define the destination type. It can be one of the following:

¡        Load-balanced connection

¡        Single server connection

The destination type for data type Dictionary metadata can only be a load-balanced connection. You therefore cannot select a single server connection.

There are two destination types available for data type Application data.

However, you should only use a single server connection for debugging a Web Dynpro application.

 

       4.      Define the application server or message server
Below you can define the application or message server type, depending on the selected connection type. If you are using a SAProuter, you can also define the SAProuter string in this step. If you selected connection type Load-balanced connection, you must define a message server.
For more information about the SAProuter, see the SAP Library under SAP NetWeaver ® Security ® SAPNetWeaver Security Guide ® Network Infrastructure ® Firewalls ® SAProuter.

       5.      Define the security settings
You have to take security matters into consideration and define the security settings when you specify a JCo destination.
You first select the required authentication method for user authentication.

¡        If you select User/Password, you must define a user and the corresponding password.

This authentication method is used to define JCo destinations for metadata. The user is predefined for authentication method User/Password and cannot be changed. This user is a technical user who does not need dialog authorization. The name and password assigned to this user must be known in the backend. The authorizations for this user must be set in the backend so that this user can access all DDIC function modules.

¡        If you select Ticket, ticket authentication is expected and you need not define a user and password.

¡        The same is true for Client Certificate (X509). You need not define a user and password here either.

You also have to make the settings for Secure Network Communication (SNC).

Note that you have to make other settings to activate the Secure Network Connection on your J2EE Engine. For detailed documentation about security, see the SAP Library at SAP NetWeaver ® Security. For information about SNC, see SAP NetWeaver ® Security ® SAPNetWeaver Security Guide ® Network Infrastructure ® Transport Layer Security ® Secure Network Communications.

       6.      Summary of the defined parameters
The last step of the wizard gives you an overview of the defined parameters. To change parameters, navigate back to the location to be changed with Previous and make the corresponding changes.
You end the wizard with Finish. You have now created a new JCo destination.

You can also edit the JCo destinations you created by selecting Maintain JCo destinations in the toolbar of the Web Dynpro Content Administrator.