杰克逊自动将 Joda DateTime 格式化为 ISO 8601 格式

Question

根据http://wiki.fasterxml.com/JacksonFAQDateHandling，“DateTime 可以自动序列化/反序列化，类似于处理 java.util.Date 的方式。”但是，我无法完成这个自动功能。有与此主题相关的 StackOverflow 讨论，但大多数都涉及基于代码的解决方案，但根据上面的引用，我应该能够通过简单的配置来完成此操作。

根据http://wiki.fasterxml.com/JacksonFAQDateHandling，我设置了我的配置，以便将日期写为时间戳是错误的。结果是 java.util.Date 类型被序列化为 ISO 8601 格式，但 org.joda.time.DateTime 类型被序列化为长对象表示。

我的环境是这样的：

杰克逊 2.1
乔达时间 2.1
春季 3.2
Java 1.6

我的 jsonMapper bean 的 Spring 配置是

@Bean
public ObjectMapper jsonMapper() {
    ObjectMapper objectMapper = new ObjectMapper();

    //Fully qualified path shows I am using latest enum
    ObjectMapper.configure(com.fasterxml.jackson.databind.SerializationFeature.
        WRITE_DATES_AS_TIMESTAMPS , false);

    return objectMapper;
}

我的测试代码sn-p是这样的

Date d = new Date();
DateTime dt = new DateTime(d); //Joda time 
Map<String, Object> link = new LinkedHashMap<String, Object>();
link.put("date", d);
link.put("createdDateTime", dt);

JSON 输出的结果 sn-p 是这样的：

{"date":"2012-12-24T21:20:47.668+0000"}

{"createdDateTime": {"year":2012,"dayOfMonth":24,"dayOfWeek":1,"era":1,"dayOfYear":359,"centuryOfEra":20,"yearOfEra":2012,"yearOfCentury":12,"weekyear":2012,"monthOfYear":12 *... remainder snipped for brevity*}}

我的期望是 DateTime 对象应该与基于配置的 Date 对象匹配。我做错了什么，或者我误解了什么？我是不是对 Jackson 文档中的 automatically 这个词读得太多了，而事实上，虽然不是 ISO 8601，但产生了一个字符串表示，正在产生广告中的自动功能？

Answer 1

我能够从 Jackson 用户邮件列表中得到答案，并希望与您分享，因为这是一个新手问题。通过阅读 Jackson Date 常见问题解答，我没有意识到需要额外的依赖项和注册，但事实就是如此。它记录在 git hub 项目页面https://github.com/FasterXML/jackson-datatype-joda

基本上，我必须向特定于 Joda 数据类型的 Jackson jar 添加另一个依赖项，然后我必须在对象映射器上注册该模块的使用。代码sn-ps如下。

对于我的 Jackson Joda 数据类型 Maven 依赖项设置，我使用了这个：

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-joda</artifactId>
    <version>${jackson.version}</version>
</dependency>

为了注册 Joda 序列化/反序列化功能，我使用了这个：

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JodaModule());
objectMapper.configure(com.fasterxml.jackson.databind.SerializationFeature.
    WRITE_DATES_AS_TIMESTAMPS , false);

Answer 2

使用 Spring Boot。

添加到您的 Maven 配置...

<dependency>
  <groupId>com.fasterxml.jackson.datatype</groupId>
  <artifactId>jackson-datatype-joda</artifactId>
  <version>2.7.5</version>
</dependency>

然后到您的 WebConfiguration...

@Configuration
public class WebConfiguration extends WebMvcConfigurerAdapter
{
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters)
    {
      final MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
      final ObjectMapper objectMapper = new ObjectMapper();

      //configure Joda serialization
      objectMapper.registerModule(new JodaModule());
      objectMapper.configure(
          com.fasterxml.jackson.databind.SerializationFeature.
            WRITE_DATES_AS_TIMESTAMPS , false);

      // Other options such as how to deal with nulls or identing...
      objectMapper.setSerializationInclusion (
         JsonInclude.Include.NON_NULL);
      objectMapper.enable(SerializationFeature.INDENT_OUTPUT);

      converter.setObjectMapper(objectMapper);
      converters.add(converter);
      super.configureMessageConverters(converters);
    }
}

Answer 3

在 Spring Boot 中，配置更加简单。您只需声明 Maven 依赖项

    <dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-joda</artifactId>
    </dependency>

然后将配置参数添加到您的 application.yml/properties 文件中：

spring.jackson.serialization.write-dates-as-timestamps: false

Answer 4

我想我会使用以下方法发布一个更新的工作示例： Spring 4.2.0.RELEASE、Jackson 2.6.1、Joda 2.8.2

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/util  http://www.springframework.org/schema/util/spring-util.xsd
        ">

    <!-- DispatcherServlet Context: defines this servlet's request-processing 
        infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <annotation-driven>
        <message-converters>
            <beans:bean
                class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <beans:property name="objectMapper" ref="objectMapper" />
            </beans:bean>
        </message-converters>
    </annotation-driven>

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving 
        up static resources in the ${webappRoot}/resources directory -->
    <resources mapping="/resources/**" location="/resources/" />

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources 
        in the /WEB-INF/views directory -->
    <beans:bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="prefix" value="/WEB-INF/views/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <beans:bean id="objectMapper"
        class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
        <beans:property name="featuresToDisable">
            <beans:array>
                <util:constant
                    static-field="com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS" />
            </beans:array>
        </beans:property>
        <beans:property name="modulesToInstall"
            value="com.fasterxml.jackson.datatype.joda.JodaModule" />
    </beans:bean>

    <beans:bean id="localeResolver"
        class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
        <beans:property name="defaultLocale" value="en" />
    </beans:bean>

    <!-- Configure the Message Locale Resources -->
    <beans:bean id="messageSource"
        class="org.springframework.context.support.ResourceBundleMessageSource">
        <beans:property name="basename" value="errors" />
    </beans:bean>

    <beans:bean id="versionSource"
        class="org.springframework.context.support.ResourceBundleMessageSource">
        <beans:property name="basename" value="version" />
    </beans:bean>


    <!-- DataSource -->
    <beans:bean id="dataSource"
        class="org.springframework.jndi.JndiObjectFactoryBean">
        <beans:property name="jndiName" value="java:comp/env/jdbc/TestDB" />
    </beans:bean>


    <!-- POJO: Configure the DAO Implementation -->
    <beans:bean id="publicationsDAO"
        class="com.test.api.publication.PublicationsDAOJdbcImpl">
        <beans:property name="dataSource" ref="dataSource" />
    </beans:bean>


    <!-- Things to auto-load -->
    <context:component-scan base-package="com.test.api" />
    <context:component-scan base-package="com.test.rest" />

</beans:beans>

API 代码

package com.test.api.publication;

import java.util.Map;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonRootName;

@JsonRootName("event")
@JsonIgnoreProperties(ignoreUnknown=true)
public class Publication {

    private Map<String, Object> tokens;
    private String href;
    private String policy_path;

    @JsonProperty("tokens")
    public Map<String, Object> getTokens() {
        return tokens;
    }

    @JsonProperty("tokens")
    public void setTokens(Map<String, Object> tokens) {
        this.tokens = tokens;
    }

    @JsonProperty("href")
    public String getHref() {
        return href;
    }

    @JsonProperty("href")
    public void setHref(String href) {
        this.href = href;
    }

    @JsonProperty("policyPath")
    public String getPolicyPath() {
        return policy_path;
    }

    @JsonProperty("policyPath")
    public void setPolicyPath(String policy_path) {
        this.policy_path = policy_path;
    }


}


package com.test.api.publication;

import javax.sql.DataSource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class PublicationsDAOJdbcImpl implements PublicationsDAO{

    static final Logger logger = LoggerFactory.getLogger(PublicationsDAOJdbcImpl.class.getName());
    private DataSource _dataSource;

    @Override
    public void setDataSource(DataSource ds) {
        // TODO Auto-generated method stub

    }

    @Override
    public void close() {
        // TODO Auto-generated method stub

    }

    @Override
    public Publication getPublication(String policyPath) {
        Publication ret = new Publication();
        //TODO: do something
        return ret;
    }

}



package com.test.rest.publication;

import java.util.HashMap;

import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.test.api.publication.Publication;
import com.test.api.publication.PublicationsDAO;
import com.test.rest.error.UnknownResourceException;

@RestController
@RequestMapping("/pub")
public class PublicationController {

        private static final Logger logger = LoggerFactory.getLogger(PublicationController.class);

        @Autowired
        @Qualifier("publicationsDAO")
        private PublicationsDAO publicationsDAO;

        /**********************************************************************************************************************
         * 
         * @param policyPath
         * @return
         * @throws UnknownResourceException
         */
        @RequestMapping(value = "/{policyPath}", method = RequestMethod.GET)
        public Publication getByPolicyPath(@PathVariable String policyPath) throws UnknownResourceException{
            logger.debug("policyPath=" + policyPath);

            Publication ret = publicationsDAO.getPublication(policyPath);

            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("TEST1", null);
            map.put("TEST2", new Integer(101));
            map.put("TEST3", "QuinnZilla");
            map.put("TEST4", new DateTime());
            ret.setTokens(map);
            return ret;

        }

}

我得到了输出结果

{
  "tokens": {
    "TEST2": 101,
    "TEST3": "QuinnZilla",
    "TEST4": "2015-10-06T16:59:35.120Z",
    "TEST1": null
  },
  "href": null,
  "policyPath": null
}