Spring boot + redis

问题

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);
    }
}

回答1:

You set the constructor as private... change it to public

@Autowired
public StudentRepositoryImpl(RedisTemplate redisTemplate) {
    this.redisTemplate = redisTemplate;
}

回答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.

来源：https://stackoverflow.com/questions/45705726/spring-boot-redis