Set properties in a work area

 

 

Overview

An application with a current work area can insert properties into the work area and retrieve the properties from the work area. The UserWorkArea interface provides two set methods for setting properties and a get method for retrieving properties. The two-argument set method inserts the property with the property mode of normal. The three-argument set method takes a property mode as the third argument. (See "Setting property modes", later in this topic.)

Both set methods take the key and the value as arguments. The key is a String; the value is an object of the type java.io.Serializable. None of the arguments can be null, which causes the java.lang.NullPointer exception to be raised.

The Example: Using work areas in the SimpleSample application uses objects of two classes, the SimpleSampleCompany class and the SimpleSampleProperty class, as values for properties. The SimpleSampleCompany class is used for the site identifier, and the SimpleSamplePriority class is used for the priority. These classes are shown in following code example:

public class SimpleSampleServlet {
   ...
   userWorkArea.begin("SimpleSampleServlet");

   try {
      // Set the site-identifier (default is Main).
      userWorkArea.set("company",
         SimpleSampleCompany.Main, PropertyModeType.read_only);

      // Set the priority.
      userWorkArea.set("priority", SimpleSamplePriority.Silver);   }

   catch (PropertyReadOnly e) {
     // The company was previously set with the read-only or
     // fixed read-only mode.
     ...   }

    catch (NotOriginator e) {
     // The work area originated in another process,
     // so it can't be modified here.
     ...   }

   catch (NoWorkArea e) {
      // There is no work area begun on this thread.
      ...   }

   // Do application work.
   ...
}

The get method takes the key as an argument and returns a Java Serializable object as the value associated with the key. For example, to retrieve the value of the company key from the work area, the code example above uses the get method on the work area to retrieve the value.

Setting property modes. The two-argument set method on the UserWorkArea interface takes a key and a value as arguments and inserts the property with the default property mode of normal. To set a property with a different mode, applications must use the three-argument set method, which takes a property mode as the third argument. The values used to request the property modes are as follows:

 

• Normal: PropertyModeType.normal

   

• Fixed normal: PropertyModeType.fixed_normal

   

• Read-only: PropertyModeType.read_only

   

• Fixed read-only: PropertyModeType.fixed_readonly

 

What to do next

For additional information about work area, see the com.ibm.websphere.workarea package in the API documentation. The generated API documentation is available in the information center table of contents from the path Reference > Developer > API documentation > Application programming interfaces.

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Work area property modes