WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

For packaging the property files, you have two approaches. Either you include
the property files within the EAR file itself or you distribute them separately. To
include them within an EAR file, the easiest approach is to create a utility JAR
project, add the property files to it, and then add that project as a dependent
project to the projects that will read the property files. The utility JAR project is
then made available on the class path for the other projects. The best practice,
however, is to centralize access to the property files using a custom property
manager class, so access to the properties is not scattered all over your code.
For example, to load a property file using the class loader, you can use the code
snippet in Example 8-1.
Example 8-1 Loading a property file using the class loader code snippet
Properties props = new Properties();
InputStream in =
MyClass.class.getClassLoader().getResourceAsStream(“my.properties”);
props.load(in);
in.close();
Property files packaged in a JAR file in the EAR file are a good solution for
property files that should not be modified after the application has been deployed
(the application-specific category described in 8.10.1, “Classifying configuration
settings” on page 301).
If you want to make the property files easily accessible after the application has
been deployed, you might want to store them in a folder outside the EAR file. To
load the property files, you either make the folder available on the class path for
the application (and use the code snippet in Example 8-1) or you use an absolute
path name and the code snippet in Example 8-2 (assuming the file to load is
/opt/apps/OrderApp/my.properties).
Example 8-2 Absolute path name code snippet
Properties props = new Properties();
InputStream in = new
FileInputStream(“/opt/apps/OrderApp/my.properties”);
props.load(in);
in.close();
Using absolute path names is usually a bad idea because it tends to hard code
strings into your code, which is not what you want to do. A better approach is to
make the folder with the property files available on the class path for the
application. You can do this by defining a shared library to WebSphere
Application Server. Instead of specifying JAR files, you specify the name of the
folder that holds the property files, such as “/opt/apps/OrderApp”, in the
Classpath field for the shared library.
Chapter 8. Application development and deployment 303