The first step is to create a superclass that all of our DAO test cases will inherit. This abstract class looks like the following code snippet:

package com.gieman.tttracker.dao;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests;

@ContextConfiguration("/testingContext.xml")
public abstract class AbstractDaoForTesting extends AbstractTransactionalJUnit4SpringContextTests {

    protected final Logger logger = LoggerFactory.getLogger(this.getClass());
    @Autowired(required = true)
    protected CompanyDao companyDao;
    @Autowired(required = true)
    protected ProjectDao projectDao;
    @Autowired(required = true)
    protected TaskDao taskDao;
    @Autowired(required = true)
    protected UserDao userDao;
    @Autowired(required = true)
    protected TaskLogDao taskLogDao;
}

The AbstractDaoForTesting class is marked as abstract so that it cannot be instantiated directly. It provides member variables that are accessible to all the subclasses, thus removing the need to replicate code in the descendents. As a result, each subclass will have access to the DAO instances as well as the SLF4J logger. There are two new Spring annotations:

The final important thing to notice is that the AbstractDaoForTesting class extends the Spring AbstractTransactionalJUnit4SpringContextTests class. Apart from being a very long class name, this class provides transparent transactional rollbacks at the end of each test method. This means the database state at the end of any DAO testing operations (including any insert, update, or delete) will be the same as at the start of testing. If this behavior is not required, you should extend AbstractJUnit4SpringContextTests instead. In this case any testing database operations can be examined and confirmed after the tests have been run. It is also possible to mark a single method with @Rollback(false) when using AbstractTransactionalJUnit4SpringContextTests to commit changes if required.

Let's now write our first test case for the CompanyDao operation.