java - 无法让 jersey 2 应用程序使用自定义 jackson XmlMapper

Question

我正在使用 Jersey 2.22.1 和 Jackson 2.6.3 编写 Web 应用程序。我的 pom.xml 看起来像这样:

<!-- JERSEY -->
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet</artifactId>
        <version>2.22.1</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-client</artifactId>
        <version>2.22.1</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-json-jackson</artifactId>
        <version>2.22.1</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-multipart</artifactId>
        <version>2.22.1</version>
    </dependency>
    <dependency>
        <groupId>asm</groupId>
        <artifactId>asm</artifactId>
        <version>3.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.woodstox</groupId>
        <artifactId>woodstox-core-asl</artifactId>
        <version>4.4.1</version>
    </dependency>
    <!-- JACKSON -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.6.3</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.6.3</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.6.3</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.dataformat</groupId>
        <artifactId>jackson-dataformat-xml</artifactId>
        <version>2.6.3</version>
    </dependency>

目标是使用不同的自定义 ObjectMappers 进行 JSON 和 XML 映射。我创建了两个提供者类:JSONMapperProvider

    @Provider
    @Produces(MediaType.APPLICATION_JSON)
    public class JSONMapperProvider implements ContextResolver<ObjectMapper> {
    private static ObjectMapper objectMapper;

    public JSONMapperProvider() {
    init();
    }

    public static void init() {
    if (objectMapper == null) {
        objectMapper = new ObjectMapper();
        // SERIALIZATION
        objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true)
            .configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false)
            .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
            .configure(SerializationFeature.WRITE_DATE_KEYS_AS_TIMESTAMPS, false)
            .setSerializationInclusion(Include.NON_NULL)
            .setSerializationInclusion(Include.NON_EMPTY);
        // DESERIALIZATION
        objectMapper.configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true)
            .configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
        // set up ISO 8601 date/time stamp format:
        ObjectMapperProvider.DATE_FORMAT_ISO8601.setTimeZone(TimeZone.getTimeZone("GMT"));
        objectMapper.setDateFormat(ObjectMapperProvider.DATE_FORMAT_ISO8601);
        // Custom deserializer for date which helps deserialization of date
        // without time
        SimpleModule dateDeserializerModule = new SimpleModule("DateDeserializerModule", Version.unknownVersion());
        dateDeserializerModule.addDeserializer(Date.class, new CustomJsonDateDeserializer());
        //objectMapper.registerModule(dateDeserializerModule);
    }
    }

    @Override
    public ObjectMapper getContext(Class<?> type) {
    System.out.println("JSONMapperProvider.getContext() called with type: "
        + type);
    return objectMapper;
    }

    private static class CustomJsonDateDeserializer extends JsonDeserializer<Date> {
    @Override
    public Date deserialize(JsonParser jsonparser, DeserializationContext deserializationcontext) throws IOException, JsonProcessingException {
        String date = jsonparser.getText();
        try {
        return DateUtil.parseDate(date);
        } catch (ParseException e) {
        throw new RuntimeException(e);
        }
    }
    }
}

和 XMLMapperProvider

    @Provider
    @Produces({ MediaType.APPLICATION_XML })
    public class XMLMapperProvider implements ContextResolver<ObjectMapper>     {

    private static ObjectMapper objectMapper;

    public XMLMapperProvider() {
    init();
    }

    public static void init() {
    if (objectMapper == null) {
        JacksonXmlModule module = new JacksonXmlModule();
        module.setDefaultUseWrapper(false);
        objectMapper = new XmlMapper(module);
        // SERIALIZATION
        objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true)
            .configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false)
            .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
            .configure(SerializationFeature.WRITE_DATE_KEYS_AS_TIMESTAMPS, false)
            .setSerializationInclusion(Include.NON_NULL)
            .setSerializationInclusion(Include.NON_EMPTY);
        // DESERIALIZATION
        objectMapper.configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true)
            .configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
        // set up ISO 8601 date/time stamp format:
        ObjectMapperProvider.DATE_FORMAT_ISO8601.setTimeZone(TimeZone.getTimeZone("GMT"));
        objectMapper.setDateFormat(ObjectMapperProvider.DATE_FORMAT_ISO8601);
        // Custom deserializer for date which helps deserialization of date
        // without time
        SimpleModule dateDeserializerModule = new SimpleModule("DateDeserializerModule", Version.unknownVersion());
        dateDeserializerModule.addDeserializer(Date.class, new CustomJsonDateDeserializer());
        objectMapper.registerModule(dateDeserializerModule);
    }
    }

    @Override
    public ObjectMapper getContext(Class<?> type) {
    System.out.println("XMLMapperProvider.getContext() called with type: "
        + type);
    return objectMapper;
    }

    private static class CustomJsonDateDeserializer extends JsonDeserializer<Date> {
    @Override
    public Date deserialize(JsonParser jsonparser, DeserializationContext deserializationcontext) throws IOException, JsonProcessingException {
        String date = jsonparser.getText();
        try {
        return DateUtil.parseDate(date);
        } catch (ParseException e) {
        throw new RuntimeException(e);
        }
    }
    }
}

它们都在同一个包中，在Application资源类中注册

@ApplicationPath("resources")
public class CCRestResources extends ResourceConfig {
    public CCRestResources() {
        register(JacksonFeature.class);
        packages("com.cc.rest.jersey");
    }
}

如果我向 @Produces(MediaType.APPLICATION_JSON) 方法发出 GET 请求，一切都很好，并且使用了我的自定义映射器。但是，如果我对 @Produces(MediaType.APPLICATION_XML) 应用程序提出相同的请求，则使用一些默认映射器而不是我的自定义映射器。如果您有任何想法，请提供帮助。谢谢!

Answer 1

所以有几件事。首先，您需要的不仅仅是核心 Jackson xml 依赖项，您还需要实际的 jaxrs provider

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-xml-provider</artifactId>
    <version>${jackson2.version}</version>
</dependency>

然后您应该排除 JAXB 提供程序，它是 Jersey 使用的默认提供程序。 (我在测试时没有遇到任何问题，但如果你不打算使用它，我会排除它)。它由 jersey-server 引入，因此您应该显式声明 jersey-server 并从中排除 jersey-media-jaxb

<dependency>
    <groupId>org.glassfish.jersey.core</groupId>
    <artifactId>jersey-server</artifactId>
    <version>${jersey2.version}</version>
    <exclusions>
        <exclusion>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-jaxb</artifactId>
        </exclusion>
    </exclusions>
</dependency>

然后您需要注册 JacksonJaxbXMLProvider (如果您不需要或不打算使用 JAXB 注释，则只需 JacksonXMLProvider)。

public CCRestResources() {
    register(JacksonFeature.class);
    register(JacksonJaxbXMLProvider.class);
    packages("com.cc.rest.jersey");
}

最后，您需要将 ContextResolver 参数化为 XmlMapper 类型，而不是 ObjectMapper。如所见here ，提供者为 XmlMapper 寻找 ContextResolver，而不是 ObjectMapper。