无法设置简单的Redis + Spring项目：“默认情况下不支持Java 8日期/时间类型`java.time.Instant`”

问题描述 投票：0回答：1

非常感谢您提前提供的帮助！我正在尝试使用 IntelliJ 建立一个简单的 Spring + Redis 项目，遗憾的是它不起作用。

我在这里检查了无数的论坛帖子，但遗憾的是没有结果。虽然其中许多内容有些相关，但它们并不相同，我无法将所提供的见解用于我的特定情况。

为了方便重现问题，我在下面列出了我所做的每一步：

项目设置

  1. 启动IntelliJ IDEA 2023.1.4（终极版）
  2. 文件 -> 新建 -> 项目... -> Spring Initializr
  3. 语言：Java
  4. 类型：Gradle - Kotlin
  5. 单击下一步
  6. Spring 启动：3.1.4
  7. 选择：Lombok + Spring Web + Spring Data Redis（访问+驱动）

应用属性

  1. 我将以下内容添加到
    application.properties
    中的
    src/main/resources
    ：
spring.data.redis.host=localhost
spring.data.redis.port=6379

（请注意，Redis 在容器中本地运行，我测试它工作正常/可以在端口 6379 上访问）

自定义数据类

  1. 右键单击主包（在我的例子中为
    com.example.demo
    ），然后单击New -> Java Class
  2. 将类命名为 
    MyObject
    并添加以下内容：
package com.example.demo;

import lombok.Data;

import java.time.Instant;

@Data
public class MyObject {
    Instant timestamp;
    String textPayload;
}

配置类

  1. 右键单击主包（在我的例子中为
    com.example.demo
    ），然后单击New -> Java Class
  2. 将类命名为 
    AppConfig
    并添加以下代码：
package com.example.demo;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class AppConfig {
    @Bean
    public RedisTemplate<String, MyObject> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, MyObject> template = new RedisTemplate<>();
        template.setConnectionFactory(factory);

        // Serialization for keys. By default, it uses JdkSerializationRedisSerializer
        template.setKeySerializer(new StringRedisSerializer());

        // Serialization for values. By default, it uses JdkSerializationRedisSerializer
        // Here, we use Jackson to convert MyObject to JSON
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());

        return template;
    }
}

创建控制器

  1. 右键单击主包（在我的例子中为
    com.example.demo
    ），然后单击New -> Java Class
  2. 将类命名为 
    MyController
    并添加以下代码：
package com.example.demo;

import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;
import lombok.experimental.FieldDefaults;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.time.Instant;

@FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
@RequiredArgsConstructor
@RestController
public class MyController {
    RedisTemplate<String, MyObject> redisTemplate;

    @GetMapping("/save")
    public ResponseEntity<String> saveObject() {
        MyObject myObject = new MyObject();
        myObject.setTimestamp(Instant.now());
        myObject.setTextPayload("some data");
        redisTemplate.opsForValue().set("myObject", myObject);
        return ResponseEntity.ok("Object saved");
    }

    @GetMapping("/read")
    public ResponseEntity<MyObject> readObject() {
        return ResponseEntity.ok(redisTemplate.opsForValue().get("myObject"));
    }
}

结果

当尝试调用 `/save/ 端点时，上述内容将导致以下异常：

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Java 8 date/time type `java.time.Instant` not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling (through reference chain: com.example.demo.MyObject["timestamp"])
    at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1308) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.impl.UnsupportedTypeSerializer.serialize(UnsupportedTypeSerializer.java:35) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:732) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:772) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeWithType(BeanSerializerBase.java:655) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.impl.TypeWrappedSerializer.serialize(TypeWrappedSerializer.java:32) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:479) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:318) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ObjectMapper._writeValueAndClose(ObjectMapper.java:4719) ~[jackson-databind-2.15.2.jar:2.15.2]
    at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsBytes(ObjectMapper.java:3987) ~[jackson-databind-2.15.2.jar:2.15.2]
    at org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer.serialize(GenericJackson2JsonRedisSerializer.java:220) ~[spring-data-redis-3.1.4.jar:3.1.4]
    at org.springframework.data.redis.core.AbstractOperations.rawValue(AbstractOperations.java:128) ~[spring-data-redis-3.1.4.jar:3.1.4]
    at org.springframework.data.redis.core.DefaultValueOperations.set(DefaultValueOperations.java:236) ~[spring-data-redis-3.1.4.jar:3.1.4]
    at com.example.demo.MyController.saveObject(MyController.java:24) ~[main/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-6.0.12.jar:6.0.12]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564) ~[tomcat-embed-core-10.1.13.jar:6.0]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.12.jar:6.0.12]
    at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658) ~[tomcat-embed-core-10.1.13.jar:6.0]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.12.jar:6.0.12]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.12.jar:6.0.12]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.12.jar:6.0.12]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.12.jar:6.0.12]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.12.jar:6.0.12]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.12.jar:6.0.12]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1740) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.13.jar:10.1.13]
    at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

解决方案#1

我的第一次尝试是遵循异常消息中给出的建议：“com.fasterxml.jackson.databind.exc.InvalidDefinitionException：Java 8日期/时间类型

java.time.Instant
默认不支持：添加模块”com.fasterxml .jackson.datatype:jackson-datatype-jsr310" 以启用处理（通过参考链：com.example.demo.MyObject["timestamp"]）"

所以我将以下行添加到我的 

build.gradle.kts
文件中：

implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310")

...然后点击 Gradle 重新加载按钮/在 IntelliJ 中按 Ctrl + Shift + O

结果：与上面相同的异常。

解决方案#2

为了更好地保留新添加的依赖项，我尝试了 Stack Overflow 上建议的其他几种解决方案。

在我的配置中为
ObjectMapper
单例添加一个bean

来源：Spring Boot 2.5.0 和 InvalidDefinitionException：Java 8 日期/时间类型 

java.time.Instant
默认不支持

    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.registerModule(new JavaTimeModule());
        return objectMapper;
    }

结果：与上面相同的异常。

解决方案#3

ObjectMapper
单例的另一种变体

来源：如何使用 Jackson 启用 JSR310 对 LocalDate 的支持？

    @Bean
    public ObjectMapper objectMapper() {
        return JsonMapper.builder()
                         .addModule(new JavaTimeModule())
                         .build();
    }

结果：与上面相同的异常。

解决方案#4

指定 
Jackson2ObjectMapperBuilder

的 bean

来源：ChatGPT的建议

    @Bean
    public Jackson2ObjectMapperBuilder jackson2ObjectMapperBuilder() {
        return new Jackson2ObjectMapperBuilder().modules(new JavaTimeModule());
    }

结果：与上面相同的异常。

帮忙？

我尝试了很多其他的方法，在这个问题上花了相当多的时间，但没有任何效果。使用 Spring/Redis 序列化 Instant 真的那么难吗？我缺少什么？有人可以帮忙吗？

提前非常感谢！

java spring redis jackson spring-data-redis
1个回答
0
投票

我注意到您正在手动创建 

GenericJackson2JsonRedisSerializer
。当您这样做时，它会自动创建一个新的 ObjectMapper，该对象不是通过 Spring 设置的，并且没有自动模块加载功能。一个快速修复方法是将 ObjectMapper 注入到 
redisTemplate
bean 函数中，或者在函数内部创建一个 ObjectMapper，然后将其交给 
GenericJackson2JsonRedisSerializer
的构造函数。这应该能解决问题。顺便说一句，采用注入路线是一个好主意，因为它允许您使用默认的全局设置的 ObjectMapper。请注意，不要忘记包含 
com.fasterxml.jackson.datatype:jackson-datatype-jsr310
依赖项。

所以一个好的解决方案可以是这样的：

@Bean
public RedisTemplate<String, MyObject> redisTemplate(RedisConnectionFactory factory, ObjectMapper mapper) {
    RedisTemplate<String, MyObject> template = new RedisTemplate<>();
    template.setConnectionFactory(factory);

    // Serialization for keys. By default, it uses JdkSerializationRedisSerializer
    template.setKeySerializer(new StringRedisSerializer());

    // Serialization for values. By default, it uses JdkSerializationRedisSerializer
    // Here, we use Jackson to convert MyObject to JSON
    template.setValueSerializer(new GenericJackson2JsonRedisSerializer(mapper));

    return template;
}

希望这有帮助！

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