Introduction to Troubleshooting FAQ

When coding on any platform, you can sometimes run into issues that have no clear resolution. This can be particularly frustrating. If you have issues building, deploying, or running modules, you want to resolve them fast. These frequently asked questions and answers help you troubleshoot problems that arise based on the underlying OSGi platform, and then correct them.

Here are the troubleshooting sections:

• Modules
• Services and Components

Click a question to view the answer.

Modules

How can I configure dependencies on Liferay Portal artifacts? 

See Configuring Dependencies.

What are optional package imports and how can I specify them? 

When developing Liferay Portal modules, you can declare optional package imports. An optional package import is one your module can use if it's available, but can still function without it. Specifying optional package imports is straightforward.

How can I connect to a JNDI data source from my module? 

Connecting to an application server's JNDI data sources from Liferay Portal's OSGi environment is almost the same as connecting to them from the Java EE environment. In an OSGi environment, the only difference is that you must use Liferay Portal's class loader to load the application server's JNDI classes.

How can I make sure my module works? 

The Testing tutorials demonstrate several ways to test Liferay Portal modules:

• Unit testing
• Integration testing
• Functional testing

My module has an unresolved requirement. What can I do? 

If one of your bundles imports a package that no other bundle in the Liferay OSGi runtime exports, Liferay Portal reports an unresolved requirement:

! could not resolve the bundles: ...
    Unresolved requirement: Import-Package: ...
    ...
    Unresolved requirement: Require-Capability ...
    

To satisfy the requirement, find a module that provides the capability, add it to your build file's dependencies, and deploy it.

An IllegalContextNameException reports that my bundle's context name does not follow Bundle-SymbolicName syntax. How can I fix the context name? 

Adjust the Bundle-SymbolicName to adhere to the syntax.

Why aren't my module's JavaScript and CSS changes showing? 

Incorrect component properties or stale browser cache can prevent JavaScript and CSS changes from showing.

Why aren't my fragment's JSP overrides showing? 

Make sure your Fragment-Host's bundle version is compatible with the host's bundle version.

The application server and database started, but Liferay DXP failed to connect to the database. What happened and how can I fix this? 

Liferay Portal initialization can fail while attempting to connect to a database server that isn't ready. Configuring Liferay Portal startup to retry JDBC connections facilitates connecting Liferay Portal to databases.

How can I adjust my module's logging? 

See Adjusting Module Logging.

How can I implement logging in my module or plugin? 

Use Simple Logging Facade for Java (SLF4J) to log messages.

Why did the entity sort order change when I migrated to a new database type? 

Your new database uses a different default query result order--you should be able to configure a different order.

Services and Components

How can I detect unresolved OSGi components? 

Liferay Portal module components that use Service Builder use Dependency Manager (DM) and most other Liferay Portal module components use Declarative Services (DS). Gogo shell commands and tools help you find and inspect unsatisfied component references for DM and DS components.

What is the safest way to call non-OSGi code that uses OSGi services? 

See Calling Non-OSGi Code that Uses OSGi Services.

How can I use files to configure components? 

See Using Files to Configure Module Components.

How can I use OSGi services from Ext Plugins? 

The registry API lets Ext Plugins use OSGi services .