104

我的目标是以objectMapper仅序列化带有注释的元素的方式配置@JsonProperty.

为了做到这一点，我遵循了这个解释，它说明了如何配置对象映射器。

我包含了这里描述的自定义对象映射器。

但是，当类NumbersOfNewEvents被序列化时，它仍然包含 json 中的所有属性。

有人有提示吗？提前致谢

杰克逊 1.8.0 春季 3.0.5

自定义对象映射器

public class CompanyObjectMapper extends ObjectMapper {
    public CompanyObjectMapper() {
        super();
        setVisibilityChecker(getSerializationConfig()
                .getDefaultVisibilityChecker()
                .withCreatorVisibility(JsonAutoDetect.Visibility.NONE)
                .withFieldVisibility(JsonAutoDetect.Visibility.NONE)
                .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withIsGetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withSetterVisibility(JsonAutoDetect.Visibility.DEFAULT));
    }
}

servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="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-3.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan base-package="de.Company.backend.web" />

    <mvc:annotation-driven />

    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                    <property name="objectMapper" ref="jacksonObjectMapper" />
                </bean>
            </list>
        </property>
    </bean>

    <bean id="jacksonObjectMapper" class="de.Company.backend.web.CompanyObjectMapper" />
</beans>

NumbersOfNewEvents

public class NumbersOfNewEvents implements StatusAttribute {

    public Integer newAccepts;
    public Integer openRequests;

    public NumbersOfNewEvents() {
        super();
    }
}
4

12 回答 12

153

使用 Spring Boot (1.2.4) 和 Jackson (2.4.6) 以下基于注释的配置对我有用。

@Configuration
public class JacksonConfiguration {

    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        mapper.configure(MapperFeature.DEFAULT_VIEW_INCLUSION, true);

        return mapper;
    }
}
于 2015-09-29T11:39:23.640 回答
27

可能是因为我使用的是 Spring 3.1（而不是您问题指定的 Spring 3.0.5），但 Steve Eastwood 的回答对我不起作用。此解决方案适用于 Spring 3.1：

在您的 spring xml 上下文中：

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
            <property name="objectMapper" ref="jacksonObjectMapper" />
        </bean>        
    </mvc:message-converters>
</mvc:annotation-driven>

<bean id="jacksonObjectMapper" class="de.Company.backend.web.CompanyObjectMapper" />
于 2011-12-22T15:44:18.737 回答
21

有很org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean长一段时间。从 Spring Boot 的 1.2 版本开始，有org.springframework.http.converter.json.Jackson2ObjectMapperBuilderJava Config。

在 String Boot 中配置可以很简单：

spring.jackson.deserialization.<feature_name>=true|false
spring.jackson.generator.<feature_name>=true|false
spring.jackson.mapper.<feature_name>=true|false
spring.jackson.parser.<feature_name>=true|false
spring.jackson.serialization.<feature_name>=true|false
spring.jackson.default-property-inclusion=always|non_null|non_absent|non_default|non_empty

在类中classpath:application.properties或一些 Java 代码中@Configuration：

@Bean
public Jackson2ObjectMapperBuilder jacksonBuilder() {
    Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
    builder.indentOutput(true).dateFormat(new SimpleDateFormat("yyyy-MM-dd"));
    return builder;
}

看：

于 2017-03-13T07:33:10.240 回答
16

我已经将它与 Jackson 2.x和 Spring 3.1.2+ 一起使用

servlet-context.xml：

请注意，根元素是<beans:beans>，因此您可能需要根据您的设置删除beans和添加mvc其中一些元素。

    <annotation-driven>
        <message-converters>
            <beans:bean
                class="org.springframework.http.converter.StringHttpMessageConverter" />
            <beans:bean
                class="org.springframework.http.converter.ResourceHttpMessageConverter" />
            <beans:bean
                class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <beans:property name="objectMapper" ref="jacksonObjectMapper" />
            </beans:bean>
        </message-converters>
    </annotation-driven>

    <beans:bean id="jacksonObjectMapper"
        class="au.edu.unimelb.atcom.transfer.json.mappers.JSONMapper" />

au.edu.unimelb.atcom.transfer.json.mappers.JSONMapper.java：

public class JSONMapper extends ObjectMapper {

    public JSONMapper() {
        SimpleModule module = new SimpleModule("JSONModule", new Version(2, 0, 0, null, null, null));
        module.addSerializer(Date.class, new DateSerializer());
        module.addDeserializer(Date.class, new DateDeserializer());
        // Add more here ...
        registerModule(module);
    }

}

日期序列化器.java：

public class DateSerializer extends StdSerializer<Date> {

    public DateSerializer() {
        super(Date.class);
    }

    @Override
    public void serialize(Date date, JsonGenerator json,
            SerializerProvider provider) throws IOException,
            JsonGenerationException {
        // The client side will handle presentation, we just want it accurate
        DateFormat df = StdDateFormat.getBlueprintISO8601Format();
        String out = df.format(date);
        json.writeString(out);
    }

}

DateDeserializer.java：

public class DateDeserializer extends StdDeserializer<Date> {

    public DateDeserializer() {
        super(Date.class);
    }

    @Override
    public Date deserialize(JsonParser json, DeserializationContext context)
            throws IOException, JsonProcessingException {
        try {
            DateFormat df = StdDateFormat.getBlueprintISO8601Format();
            return df.parse(json.getText());
        } catch (ParseException e) {
            return null;
        }
    }

}
于 2012-09-27T09:11:39.790 回答
13

解决方案 1

第一个（经过测试的）工作解决方案很有用，尤其是在使用时@EnableWebMvc：

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private ObjectMapper objectMapper;// created elsewhere
    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        // this won't add a 2nd MappingJackson2HttpMessageConverter 
        // as the SOLUTION 2 is doing but also might seem complicated
        converters.stream().filter(c -> c instanceof MappingJackson2HttpMessageConverter).forEach(c -> {
            // check default included objectMapper._registeredModuleTypes,
            // e.g. Jdk8Module, JavaTimeModule when creating the ObjectMapper
            // without Jackson2ObjectMapperBuilder
            ((MappingJackson2HttpMessageConverter) c).setObjectMapper(this.objectMapper);
        });
    }

解决方案 2

当然，下面的常用方法也适用（也适用于@EnableWebMvc）：

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private ObjectMapper objectMapper;// created elsewhere
    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        // this will add a 2nd MappingJackson2HttpMessageConverter 
        // (additional to the default one) but will work and you 
        // won't lose the default converters as you'll do when overwriting
        // configureMessageConverters(List<HttpMessageConverter<?>> converters)
        // 
        // you still have to check default included
        // objectMapper._registeredModuleTypes, e.g.
        // Jdk8Module, JavaTimeModule when creating the ObjectMapper
        // without Jackson2ObjectMapperBuilder
        converters.add(new MappingJackson2HttpMessageConverter(this.objectMapper));
    }

为什么@EnableWebMvc 的使用是个问题？

@EnableWebMvc正在使用DelegatingWebMvcConfigurationwhich extends WebMvcConfigurationSupportwhich 这样做：

if (jackson2Present) {
    Jackson2ObjectMapperBuilder builder = Jackson2ObjectMapperBuilder.json();
    if (this.applicationContext != null) {
        builder.applicationContext(this.applicationContext);
    }
    messageConverters.add(new MappingJackson2HttpMessageConverter(builder.build()));
}

这意味着没有办法注入您自己ObjectMapper的以准备将其用于MappingJackson2HttpMessageConverter在使用@EnableWebMvc.

于 2019-05-02T19:19:21.423 回答
10

我现在找到了基于https://github.com/FasterXML/jackson-module-hibernate的解决方案

我扩展了对象映射器并在继承的构造函数中添加了属性。

然后将新的对象映射器注册为 bean。

<!-- https://github.com/FasterXML/jackson-module-hibernate -->
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    <property name="messageConverters">
        <array>
            <bean id="jsonConverter"
            class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                <property name="objectMapper">
                    <bean class="de.company.backend.spring.PtxObjectMapper"/>
                </property>
            </bean>
        </array>
    </property>
</bean>
于 2011-10-31T09:21:24.970 回答
9

如果您想添加自定义 ObjectMapper 来注册自定义序列化程序，请尝试我的回答。

就我而言（Spring 3.2.4 和 Jackson 2.3.1），自定义序列化程序的 XML 配置：

<mvc:annotation-driven>
    <mvc:message-converters register-defaults="false">
        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="objectMapper">
                <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                    <property name="serializers">
                        <array>
                            <bean class="com.example.business.serializer.json.CustomObjectSerializer"/>
                        </array>
                    </property>
                </bean>
            </property>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

以无法解释的方式被某些东西覆盖回默认值。

这对我有用：

自定义对象.java

@JsonSerialize(using = CustomObjectSerializer.class)
public class CustomObject {

    private Long value;

    public Long getValue() {
        return value;
    }

    public void setValue(Long value) {
        this.value = value;
    }
}

CustomObjectSerializer.java

public class CustomObjectSerializer extends JsonSerializer<CustomObject> {

    @Override
    public void serialize(CustomObject value, JsonGenerator jgen,
        SerializerProvider provider) throws IOException,JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeNumberField("y", value.getValue());
        jgen.writeEndObject();
    }

    @Override
    public Class<CustomObject> handledType() {
        return CustomObject.class;
    }
}

<mvc:message-converters>(...)</mvc:message-converters>我的解决方案中不需要 XML 配置 ( )。

于 2014-02-12T11:24:39.947 回答
6

我正在使用 Spring 4.1.6 和 Jackson FasterXML 2.1.4。

    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="com.fasterxml.jackson.databind.ObjectMapper">
                        <!-- 设置不输出null字段-->
                        <property name="serializationInclusion" value="NON_NULL"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

这适用于我的 applicationContext.xml 配置

于 2016-05-12T10:23:08.977 回答
4

要在纯 spring-web 中配置消息转换器，在这种情况下要启用 Java 8 JSR-310 JavaTimeModule，您首先需要WebMvcConfigurer在您的@Configuration类中实现，然后覆盖该configureMessageConverters方法：

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json().modules(new JavaTimeModule(), new Jdk8Module()).build()
            .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
    converters.add(new MappingJackson2HttpMessageConverter(objectMapper));
}

ObjectMapper像这样，您可以注册在基于 Java 的 Spring 配置中定义的任何自定义。

于 2018-03-21T10:57:17.593 回答
3

在 Spring Boot2.2.x中，您需要像这样配置它：

@Bean
public ObjectMapper objectMapper(Jackson2ObjectMapperBuilder builder) {
    return builder.build()
}

科特林：

@Bean
fun objectMapper(builder: Jackson2ObjectMapperBuilder) = builder.build()
于 2020-03-27T10:39:52.197 回答
2

MappingJacksonHttpMessageConverter在 Spring 4 以上，如果只打算配置，则无需配置ObjectMapper。

（配置MappingJacksonHttpMessageConverter会导致你丢失其他MessageConverter）

你只需要这样做：

public class MyObjectMapper extends ObjectMapper {

    private static final long serialVersionUID = 4219938065516862637L;

    public MyObjectMapper() {
        super();
        enable(SerializationFeature.INDENT_OUTPUT);
    }       
}

在你的 Spring 配置中，创建这个 bean：

@Bean 
public MyObjectMapper myObjectMapper() {        
    return new MyObjectMapper();
}
于 2017-10-19T06:41:10.233 回答
1

我正在使用 Spring 3.2.4 和 Jackson FasterXML 2.1.1。

我创建了一个自定义 JacksonObjectMapper，它与映射对象的每个属性的显式注释一起使用：

package com.test;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

public class MyJaxbJacksonObjectMapper extends ObjectMapper {

public MyJaxbJacksonObjectMapper() {

    this.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY)
            .setVisibility(PropertyAccessor.CREATOR, JsonAutoDetect.Visibility.ANY)
            .setVisibility(PropertyAccessor.SETTER, JsonAutoDetect.Visibility.NONE)
            .setVisibility(PropertyAccessor.GETTER, JsonAutoDetect.Visibility.NONE)
            .setVisibility(PropertyAccessor.IS_GETTER, JsonAutoDetect.Visibility.NONE);

    this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
    }
}

然后在上下文配置（servlet-context.xml）中实例化：

<mvc:annotation-driven>
    <mvc:message-converters>

        <beans:bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <beans:property name="objectMapper">
                <beans:bean class="com.test.MyJaxbJacksonObjectMapper" />
            </beans:property>
        </beans:bean>

    </mvc:message-converters>
</mvc:annotation-driven>

这很好用！

于 2014-03-18T11:24:30.017 回答