java - Jackson 不忽略空值

Question

这是我的对象

public class TokenTO {
    private String clientId;
    private String clientSecret;
    private String authCode;
    private String authToken;
    ....
}

当我收到 JSON 响应时，我看到

{"clientId":null,"clientSecret":null,"authCode":null,"authToken":"312301658396979836978200915715157679015:80bf41c2-bc97-492f-a65e-172bef9efb7c:922000000"} 

我的JacksonContextResolver看起来像

public JacksonContextResolver() {
        objectMapper = new ObjectMapper()
                .setSerializationInclusion(JsonSerialize.Inclusion.ALWAYS);

        final AnnotationIntrospector annotationIntrospector = new JaxbAnnotationIntrospector();
        objectMapper
                .enable(DeserializationConfig.Feature.READ_ENUMS_USING_TO_STRING)
                .setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL)
                .setDeserializationConfig(objectMapper.getDeserializationConfig().withAnnotationIntrospector(annotationIntrospector))
                .setSerializationConfig(objectMapper.getSerializationConfig().withAnnotationIntrospector(annotationIntrospector));
    }  

我尝试了 How to tell Jackson to ignore a field during serialization if its value is null? 中的答案和jackson ignore empty values (or null)但它们都不起作用。

我的 maven 依赖项看起来像

 <properties>
     <jaxrs-api.version>3.0.8.Final</jaxrs-api.version>
     <maven-war-plugin.version>2.4</maven-war-plugin.version>
     <resteasy-jaxrs.version>3.0.9.Final</resteasy-jaxrs.version>
     <jackson.version>1.9.13</jackson.version>
    <jaxrs-api.version>3.0.8.Final</jaxrs-api.version>
 </properties>
 <dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-xc</artifactId>
    <version>${jackson.version}</version>
</dependency>

问题

如何删除 JSON 中的 null 值？

Answer 1

由于我使用的是 Java EE 7，因此我尝试使用 JSON Processing .

我所做的更改是

为了测试，我添加了

    <dependency>
        <groupId>org.glassfish</groupId>
        <artifactId>javax.json</artifactId>
        <version>1.0.4</version>
        <scope>test</scope>
    </dependency>

在源代码中，我创建了 JSON 为

public JsonObject getAuthToken(@Nonnull final TokenManager tokenManager) {
        final String token = tokenManager.getAccessToken(clientId, clientSecret, authCode);
        return Json.createObjectBuilder().add("authToken", token).build();
    }

为了测试，我做了一些事情

final JsonObject jsonReply = getJsonObjectFromResponse(response);
assertNotNull(jsonReply.getString("authToken"));

和

    @Nonnull
    protected JsonObject getJsonObjectFromResponse(@Nonnull final Response response) {
        final JsonReader jsonReader = Json.createReader(new StringReader(response.readEntity(String.class)));
        return jsonReader.readObject();
    }

现在，部署后，我只能看到我创建的内容

{"authToken":"165099393037221788471723459805657963846:8b0f2514-938f-4509-964f-ee073dbab4ed:238000000"} 

所以我根本不使用Jackson，而且我的代码更加简洁