Spring boot + redis - spring-boot

Question

I am working demo Spring boot application with integration of Redis.
I have referred various site reference but lastly I preferred to follow this: http://www.baeldung.com/spring-data-redis-tutorial
My code is almost same as given in above link. Only change is that I have autowired StudentRepository in my RestController class.
Now when I try to do maven-install at that time it gives me error that
java.lang.IllegalStateException: Failed to load ApplicationContext
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentController': Unsatisfied dependency expressed through field 'studentRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentRepositoryImpl' defined in file [/home/klevu/work/Nimesh/Spring Boot Workspace/bootDemo/target/classes/com/example/demo/redis/repository/StudentRepositoryImpl.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class com.example.demo.redis.repository.StudentRepositoryImpl]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class com.example.demo.redis.repository.StudentRepositoryImpl
When I tried to keep constructor public, it creates build successfully. But I don't know I should do it or not here. I was thinking that rather than Autowiring constructor, I should be able to do setter injection. I also tried below:
#Autowired
private RedisTemplate<String, Student> redisTemplate;
But it is also not working.
package com.example.demo.redis.repository;
import java.util.Map;
import javax.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Repository;
import com.example.demo.redis.bean.Student;
#Repository
public class StudentRepositoryImpl implements StudentRepository {
private static final String KEY = "Student";
//#Autowired
private RedisTemplate<String, Student> redisTemplate;
private HashOperations<String, String, Student> hashOps;
#Autowired
private StudentRepositoryImpl(RedisTemplate redisTemplate) {
this.redisTemplate = redisTemplate;
}
#PostConstruct
private void init() {
hashOps = redisTemplate.opsForHash();
}
#Override
public void saveStudent(Student person) {
hashOps.put(KEY, person.getId(), person);
}
#Override
public void updateStudent(Student person) {
hashOps.put(KEY, person.getId(), person);
}
#Override
public Student findStudent(String id) {
return hashOps.get(KEY, id);
}
#Override
public Map<String, Student> findAllStudents() {
return hashOps.entries(KEY);
}
#Override
public void deleteStudent(String id) {
hashOps.delete(KEY, id);
}
}
RedisConfiguration are default and code as below:
package com.example.demo.configuration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
#Configuration
public class RedisConfiguration {
#Bean
JedisConnectionFactory jedisConnectionFactory() {
return new JedisConnectionFactory();
}
#Bean
public RedisTemplate<String, Object> redisTemplate(){
RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
template.setConnectionFactory(jedisConnectionFactory());
return template;
}
}
Spring boot main entry point is declared as below:
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import org.springframework.data.redis.repository.configuration.EnableRedisRepositories;
#SpringBootApplication
#EnableMongoRepositories(basePackages = {"com.example.demo.mongo.repository"} )
#EnableRedisRepositories(basePackages = {"com.example.demo.redis.repository"})
public class BootDemoApplication {
public static void main(String[] args) {
SpringApplication.run(BootDemoApplication.class, args);
}
}
Demo controller to test redis is as below:
package com.example.demo.controller;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.example.demo.redis.bean.Student;
import com.example.demo.redis.repository.StudentRepository;
#RestController
#RequestMapping("/student")
public class StudentController {
#Autowired
private StudentRepository studentRepository;
#GetMapping
public ResponseEntity<Map<String, Student>> index() {
Map<String, Student> students = studentRepository.findAllStudents();
return new ResponseEntity<Map<String, Student>>(students, HttpStatus.OK);
}
#RequestMapping(method = RequestMethod.GET, value = "/{id}")
public ResponseEntity<Student> getStudentById(#PathVariable("id") String id) {
Student student = studentRepository.findStudent(id);
return new ResponseEntity<Student>(student, HttpStatus.OK);
}
#RequestMapping(method = RequestMethod.POST)
public ResponseEntity<Student> saveStudent(#RequestBody Student student) {
studentRepository.saveStudent(student);
return new ResponseEntity<Student>(student, HttpStatus.CREATED);
}
#RequestMapping(method = RequestMethod.PUT, value = "/{id}")
public ResponseEntity<Student> updateStudent(#RequestBody Student student) {
studentRepository.updateStudent(student);
return new ResponseEntity<Student>(student, HttpStatus.OK);
}
#RequestMapping(method = RequestMethod.DELETE, value = "/{id}")
public ResponseEntity<Student> deleteMessage(#PathVariable("id") String id) {
studentRepository.deleteStudent(id);
return new ResponseEntity<Student>(HttpStatus.OK);
}
}

Answer 1

You set the constructor as private... change it to public
#Autowired
public StudentRepositoryImpl(RedisTemplate redisTemplate) {
this.redisTemplate = redisTemplate;
}

Answer 2

Change the following redis configuration:
Your original:
#Bean
public RedisTemplate<String, Object> redisTemplate() {
...
}
Change it to:
#Bean
public RedisTemplate<String, ?> redisTemplate(){
...
}
It should work now for you.

Answer 3

You could use Spring Data Redis
Add dependencies:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</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-data-redis</artifactId>
</dependency>
Enable Caching
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
#SpringBootApplication
#EnableCaching
public class RedisDemoApplication {
public static void main(String[] args) {
SpringApplication.run(RedisDemoApplication.class, args);
}
}
Add Cacheable annotation at method to cache in redis
#Cacheable(value = "employee", key = "#id")
public Employee getEmployee(Integer id) {
log.info("Get Employee By Id: {}", id);
Optional<Employee> employeeOptional = employeeRepository.findById(id);
if (!employeeOptional.isPresent()) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Id Not foud");
}
return employeeOptional.get();
}