What is JNDI Name?
In a software context, a JNDI name is a string that uniquely identifies an object or resource in a Java naming and directory interface (JNDI)-compliant naming service. This naming service allows applications to access resources without hard-coding the resource's physical location or implementation details.
The JNDI name is similar to a URL in that it specifies the protocol, hostname, and port of the resource, but it also includes a path to the resource within the naming service. JNDI names are often used in Java Enterprise Edition (JEE) applications to access resources such as data sources, message queues, and EJBs.
Where to Find JNDI Name in WebLogic
There are a few ways to find the JNDI name of a resource in WebLogic.
- Use the WebLogic Server Administration Console:
Log in to the WebLogic Server Administration Console and navigate to the ‘Resources’ tab. Then, select the type of resource you are interested in (e.g., ‘JDBC Data Sources’). Right-click on the resource and select ‘Properties’. The JNDI name of the resource will be displayed in the ‘Name’ field. - Use the WebLogic Server Command Line Interface (CLI):
Open a command prompt and navigate to the directory where the WebLogic Server CLI is installed (e.g., C:\Oracle\Middleware\wlserver\server\bin). Then, run the following command:java weblogic.WLST
This will start the WebLogic Server CLI. Once the CLI is running, connect to the WebLogic Server instance you are interested in by running the following command:
connect(<username>, <password>, <url>)
Where <username> is the username of the WebLogic Server administrator, <password> is the password of the WebLogic Server administrator, and <url> is the URL of the WebLogic Server instance (e.g., t3://localhost:7001).
Once you are connected to the WebLogic Server instance, run the following command to get the JNDI name of a resource:
print(get('JDBCDataSource', '<name>').getJNDIName())
Where '<name>' is the name of the resource you are interested in.
- Use a Java application:
You can also use a Java application to find the JNDI name of a resource in WebLogic. The following code snippet shows an example of how to do this:import javax.naming.*; public class FindJNDIName { public static void main(String[] args) { try { // Create a JNDI context factory InitialContextFactory contextFactory = new com.sun.jndi.rmi.registry.RegistryContextFactory(); // Create a JNDI context Context context = contextFactory.getInitialContext(); // Look up the resource Object resource = context.lookup("jdbc/myDataSource"); // Print the JNDI name of the resource System.out.println(resource.toString()); } catch (NamingException e) { System.err.println("Error finding JNDI name: " + e.getMessage()); } } }
Things to Keep in Mind
When looking up JNDI names in WebLogic, there are a few things to keep in mind:
- The JNDI name is case-sensitive.
- The JNDI name must be unique within the naming service.
- The JNDI name can be changed at any time, but this can have unintended consequences for applications that rely on the resource.
Conclusion
JNDI names are a powerful tool for accessing resources in a Java application. By understanding how to find the JNDI name of a resource in WebLogic, you can make your applications more flexible and maintainable. It enables applications to access resources without hard-coding the resource's physical location or implementation details.
For instance, you can move the resource to a different server without having to change the code in the application. This flexibility is especially valuable in large-scale distributed systems where resources may be located on different servers.
FAQs
Q1. What is a JNDI name in WebLogic?
A1. A JNDI name is a string that uniquely identifies an object or resource in a Java naming and directory interface (JNDI)-compliant naming service in WebLogic.
Q2. How do I find the JNDI name of a resource in WebLogic?
A2. You can find the JNDI name of a resource in WebLogic by using the WebLogic Server Administration Console, the WebLogic Server Command Line Interface (CLI), or a Java application.
Q3. What are some things to keep in mind when looking up JNDI names in WebLogic?
A3. When looking up JNDI names in WebLogic, there are a few things to keep in mind, such as the case-sensitivity of the name, its uniqueness within the naming service, and the potential unintended consequences of changing the name.
Q4. What are the benefits of using JNDI names in a Java application?
A4. JNDI names provide several benefits in a Java application, including increased flexibility and maintainability, as well as improved scalability and performance.
Q5. Can I use JNDI names in other application servers besides WebLogic?
A5. Yes, JNDI names can be used in other application servers besides WebLogic, as long as the application server supports the Java naming and directory interface (JNDI).