问题
I am using Spring Data Redis with the Spring Boot 2.0 example. In this example, I am trying to save the Customer data + Student data together. I'm not very sure how the data modelling happens here, but assuming its same like as Mongo DB (pure non relational).
Could someone please help with the below error ? As its clear that some conversion has been expected to see the data.
Error:
org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [com.javasampleapproach.redis.model.Customer] to type [java.lang.String]
at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:321)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:194)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:174)
at org.springframework.data.redis.serializer.GenericToStringSerializer$Converter.convert(GenericToStringSerializer.java:120)
at org.springframework.data.redis.serializer.GenericToStringSerializer.serialize(GenericToStringSerializer.java:88)
at org.springframework.data.redis.core.AbstractOperations.rawHashValue(AbstractOperations.java:184)
at org.springframework.data.redis.core.DefaultHashOperations.put(DefaultHashOperations.java:175)
at com.javasampleapproach.redis.repository.CustomerRepositoryImpl.save(CustomerRepositoryImpl.java:33)
at com.javasampleapproach.redis.repository.CustomerRepositoryImpl$$FastClassBySpringCGLIB$$88e26a2c.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at com.javasampleapproach.redis.repository.CustomerRepositoryImpl$$EnhancerBySpringCGLIB$$7d20fd4e.save(<generated>)
at com.javasampleapproach.controller.WebController.save(WebController.java:31)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
RedisConfig.java
@Configuration
@ComponentScan("com.javasampleapproach.*")
public class RedisConfig {
@Bean
public JedisConnectionFactory jedisConnectionFactory() {
return new JedisConnectionFactory();
}
@Bean
public RedisTemplate<String, Object> redisTemplate(){
final RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(jedisConnectionFactory());
template.setKeySerializer(new StringRedisSerializer());
template.setHashValueSerializer(new GenericToStringSerializer<Object>(Object.class));
template.setValueSerializer(new GenericToStringSerializer<Object>(Object.class));
return template;
}
}
Controller.java
@RequestMapping("/save")
public String save() {
List<Student> students = new ArrayList<>();
Student student = Student.builder().firstName("John").build();
students.add(student);
customerRepository.save(Customer.builder().id(1).firstName("Jack").lastName("Smith").students(students).build());
return "Done";
}
CustomerRepositoryImpl.java
@Repository
public class CustomerRepositoryImpl implements CustomerRepository {
private static final String KEY = "Customer";
private RedisTemplate<String, Object> redisTemplate;
private HashOperations<String, Long, Customer> hashOperations;
@Autowired
public CustomerRepositoryImpl(RedisTemplate<String, Object> redisTemplate) {
this.redisTemplate = redisTemplate;
}
@PostConstruct
private void init() {
hashOperations = redisTemplate.opsForHash();
}
@Override
public void save(Customer customer) {
hashOperations.put(KEY, customer.getId(), customer);
}
@Override
public Customer find(Long id) {
return hashOperations.get(KEY, id);
}
@Override
public Map<Long, Customer> findAll() {
return hashOperations.entries(KEY);
}
@Override
public void update(Customer customer) {
hashOperations.put(KEY, customer.getId(), customer);
}
@Override
public void delete(Long id) {
hashOperations.delete(KEY, id);
}
}
pom.xml
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
回答1:
You should use a serializer before persisting your object. See this part of the Spring Data Redis docs:
Data can be stored by using various data structures within Redis. Jackson2JsonRedisSerializer can convert objects in JSON format. Ideally, JSON can be stored as a value by using plain keys. You can achieve a more sophisticated mapping of structured objects by using Redis hashes. Spring Data Redis offers various strategies for mapping data to hashes (depending on the use case):
- Direct mapping, by using HashOperations and a serializer
- Using Redis Repositories
- Using HashMapper and HashOperations
EDIT:
Replace your GenericToStringSerializer in the RedisTemplate bean definition with JdkSerializationRedisSerializer (the default serializer) or Jackson2JsonRedisSerializer or GenericJackson2JsonRedisSerializer to serialize in JSON format.
回答2:
As per guidance from @Gustavo Passini and taking reference from https://www.programcreek.com/java-api-examples/index.php?api=org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer.
Here is the
@Bean
public RedisTemplate<String, Object> redisTemplate(){
Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
final RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(jedisConnectionFactory());
template.setKeySerializer(new StringRedisSerializer());
template.setHashValueSerializer(jackson2JsonRedisSerializer);
template.setValueSerializer(jackson2JsonRedisSerializer);
return template;
}
来源：https://stackoverflow.com/questions/53119756/org-springframework-core-convert-converternotfoundexception-no-converter-found