Overriding Liferay Services (Service Wrappers)

Why might you need to customize Liferay services? Perhaps you’ve added a new field to Liferay’s User object and you want its value to be saved whenever the addUser or updateUser methods of Liferay’s API are called. Or maybe you want to add some additional logging functionality to some Liferay APIs or other services built using Service Builder. Whatever your case may be, Liferay’s service wrappers provide easy-to-use extension points for customizing Liferay’s services.

To create a module that overrides one of Liferay’s services, follow the Service Wrapper Template reference article to create a servicewrapper project type.

As an example, here’s the UserLocalServiceOverride class that’s generated in the Service Wrapper Template tutorial:

package com.liferay.docs.serviceoverride;

import com.liferay.portal.kernel.service.UserLocalServiceWrapper;
import com.liferay.portal.kernel.service.ServiceWrapper;
import org.osgi.service.component.annotations.Component;

@Component(
    immediate = true,
    property = {
    },
    service = ServiceWrapper.class
)
public class UserLocalServiceOverride extends UserLocalServiceWrapper {

    public UserLocalServiceOverride() {
        super(null);
    }

}

Notice that you must specify the fully qualified class name of the service wrapper class that you want to extend. The service argument was used in full in this import statement:

import com.liferay.portal.service.UserLocalServiceWrapper

This import statement, in turn, allowed the short form of the service wrapper class name to be used in the class declaration of your component class:

public class UserLocalServiceOverride extends UserLocalServiceWrapper

The bottom line is that when using blade create to create a service wrapper project, you must specify a fully qualified class name as the service argument. (This is also true when using blade create to create a service project.) For information about creating service projects, please see the Service Builder tutorial.

The generated UserLocalServiceOverride class does not actually customize any Liferay service. Before you can test that your service wrapper module actually works, you need to override at least one service method.

Open your UserLocalServiceOverride class and add the following methods:

@Override
public int authenticateByEmailAddress(long companyId, String emailAddress,
        String password, Map<String, String[]> headerMap,
        Map<String, String[]> parameterMap, Map<String, Object> resultsMap)
    throws PortalException {

    System.out.println(
        "Authenticating user by email address " + emailAddress);
    return super.authenticateByEmailAddress(companyId, emailAddress, password,
        headerMap, parameterMap, resultsMap);
}

@Override
public User getUser(long userId) throws PortalException {
    System.out.println("Getting user by id " + userId);
    return super.getUser(userId);
}

Each of these methods overrides a Liferay service method. These implementations merely execute a few print statements that before executing the original service implementations.

Lastly, you must add the following method to the bottom of your service wrapper so it can find the appropriate service it’s overriding on deployment.

@Reference(unbind = "-")
private void serviceSetter(UserLocalService userLocalService) {
    setWrappedService(userLocalService);
}

Build and deploy your module. Congratulations! You’ve created and deployed a Liferay service wrapper!

Related Topics

Upgrading Service Wrappers

Installing Blade CLI

Creating Projects with Blade CLI