How to enable basic caching with Spring Data JPA - spring

Question

I am trying to enable basic caching with Spring Data JPA. But I cannot understand why the DAO methods are still querying the database instead of using the cache.
Given the following Spring Boot 1.5.1 application
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
#SpringBootApplication
#EnableCaching
public class Server{
public static void main(String[] args) {
SpringApplication.run(Server.class, args);
}
}
Controller
#Controller
public class PasswordsController {
#Autowired
private PasswordService service;
#SuppressWarnings("unchecked")
#RequestMapping("/passwords.htm")
public void passwords(Map model,
HttpServletRequest request) {
model.put("passwords", service.getPasswords(request));
}
...
Service
#Service
#Transactional
public class PasswordService extends BaseService {
#Autowired
private PasswordJpaDao passwordDao;
public Collection<Password> getPasswords(HttpServletRequest request) {
Collection<Password> passwords = passwordDao.getPasswords(params);
return passwords;
}
...
Interface
#Transactional
public interface PasswordJpaDaoCustom {
public Collection<Password> getPasswords(PasswordSearchParameters params);
}
and implementation
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.transaction.Transactional;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Repository;
import com.crm.entity.Password;
import com.crm.search.PasswordSearchParameters;
#Transactional
#Repository
public class PasswordJpaDaoImpl implements PasswordJpaDaoCustom {
#PersistenceContext
private EntityManager em;
#Override
#Cacheable("passwords")
public Collection<Password> getPasswords(PasswordSearchParameters params) {
System.err.println("got here");
return em.createQuery(hql, Password.class);
}
...
Maven Dependencies
<!-- Spring Boot start -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<!-- Spring Boot end -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
</dependency>
I understand that Spring Boot will implicitly use ConcurrentHashMap for caching without any specific configuration necessary?
But the getPasswords() dao method is always called instead of using the cache. Why is this?

Answer 1

Yes, spring boot by default uses ConcurrentHashMap for caching and the issue with your code is that you did not set any key for your passwords cache, so it is calling the database every time for fetching the data.
So you need to the key (any unique identifier) using the params object variables as shown below:
#Cacheable(value="passwords", key="#params.id")//any unique identifier
public Collection<Password> getPasswords(PasswordSearchParameters params) {
System.err.println("got here");
return em.createQuery(hql, Password.class);
}