无法在 Spring Boot 中使用 Crud Repository 从 Redis 获取结果?
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【中文标题】无法在 Spring Boot 中使用 Crud Repository 从 Redis 获取结果?【英文标题】:Unable to get result from the Redis using Crud Repository in Spring Boot? 【发布时间】:2019-04-06 21:05:06 【问题描述】:我正在开发 Spring Boot + Redis 示例。我从链接中获取了参考:https://www.baeldung.com/spring-data-redis-tutorial。在此示例中,我开发了存储库方法 Student findByNameAndGender(String name, Gender gender);
甚至是 Student findByName(String name);
,但在这两种情况下我都没有得到任何结果。?
有什么快速的帮助吗? Redis 查询 -
redis 127.0.0.1:6379> KEYS *
1) "Student"
2) "Student:bb4df14a-7f42-4fc3-b608-fc4b7d45109e"
3) "Student:69affaa4-e56c-49e3-9ef4-1cd7509d299b"
redis 127.0.0.1:6379>
Student.java
@Data
@AllArgsConstructor
@Builder
@NoArgsConstructor
@RedisHash("Student")
public class Student
public enum Gender
MALE, FEMALE
private String id;
private String name;
private Gender gender;
private int grade;
StudentRepository.java
@Repository
public interface StudentRepository extends CrudRepository<Student, String>
Student findByNameAndGender(String name, Gender gender);
RedisConfig.java
@Configuration
@EnableRedisRepositories
public class RedisConfig
@Bean
JedisConnectionFactory jedisConnectionFactory()
return new JedisConnectionFactory();
@Bean
public RedisTemplate<String, Object> redisTemplate()
final RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
template.setConnectionFactory(jedisConnectionFactory());
template.setValueSerializer(new GenericToStringSerializer<Object>(Object.class));
return template;
SpringDataRedisEugenpApplication.java
@SpringBootApplication
public class SpringDataRedisEugenpApplication implements CommandLineRunner
@Autowired
private StudentRepository repository;
public static void main(String[] args)
SpringApplication.run(SpringDataRedisEugenpApplication.class, args);
@Override
public void run(String... args) throws Exception
repository.save(Student.builder().name("John").gender(Student.Gender.MALE).grade(1).build());
repository.save(Student.builder().name("Michael").gender(Student.Gender.MALE).grade(2).build());
Iterable<Student> students = repository.findAll();
for (Student student : students)
System.out.println("=============================");
System.out.println("Details ? "+student.toString());
Student s = repository.findByNameAndGender("John", Student.Gender.MALE);
System.out.println("Student ="+s.toString()); //line-34
错误 -
java.lang.IllegalStateException: Failed to execute CommandLineRunner
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:795) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:776) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1242) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1230) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at com.baeldung.SpringDataRedisEugenpApplication.main(SpringDataRedisEugenpApplication.java:19) [classes/:na]
Caused by: java.lang.NullPointerException: null
at com.baeldung.SpringDataRedisEugenpApplication.run(SpringDataRedisEugenpApplication.java:34) [classes/:na]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:792) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
... 5 common frames omitted
很少的查询 -
1)如何查看redis中实际存储的数据?
2)我们如何控制Id从一个开始?
edis 127.0.0.1:6379> get Student:1
(error) ERR Operation against a key holding the wrong kind of value
redis 127.0.0.1:6379> get Student:2
(error) ERR Operation against a key holding the wrong kind of value
redis 127.0.0.1:6379>
我真的很难看到
redis 127.0.0.1:6379> mget Student:1
1) (nil)
redis 127.0.0.1:6379> mget Student:2
1) (nil)
redis 127.0.0.1:6379> mget Student
1) (nil)
【问题讨论】:
34
在你的SpringDataRedisEugenpApplication
类中是哪一行?
【参考方案1】:
我自己能够找出以下问题的答案。
您只需将@Index
注释放在字段级别。 @Index
注释将该属性标记为用于索引,它使用 Redis @literal SET 来跟踪具有匹配值的对象。
@Indexed
private String name;
@Ref:https://scalegrid.io/blog/introduction-to-redis-data-structures-hashes/
1) 如何查看redis中实际存储的数据?
redis 127.0.0.1:6379> hgetall Student:1
1) "_class"
2) "com.baeldung.spring.data.redis.model.Student"
3) "id"
4) "1"
5) "name"
6) "John Doe"
7) "gender"
8) "MALE"
9) "grade._class"
10) "java.lang.Integer"
11) "grade"
12) "1"
redis 127.0.0.1:6379> hgetall Student:2
1) "_class"
2) "com.baeldung.spring.data.redis.model.Student"
3) "id"
4) "2"
5) "name"
6) "Michael Harford"
7) "gender"
8) "MALE"
9) "grade._class"
10) "java.lang.Integer"
11) "grade"
12) "2"
【讨论】:
您是否在名称和性别字段中添加了@Index 注释?我可以把它们放到 id 字段中吗? @mertaksu - 是的,你可以这样做,如果你这样做,你可以看到已经为它创建了单独的索引数据结构 不适合我。尝试了几乎所有关于 SO 的建议。我正在使用 redis 服务器版本 6.0.9 和 spring-boot 2.3.5。我有一个类用户和另一个类地址。用户有一个地址列表。我没有用任何东西注释地址。但是将 @Indexed 放在 User 类中的属性“名称”上。使用 CrudRepository以上是关于无法在 Spring Boot 中使用 Crud Repository 从 Redis 获取结果?的主要内容,如果未能解决你的问题,请参考以下文章
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