SpringBoot 2.2.2：用于自定义分页的Jackson序列化器不起作用

2024-05-12 • 问答

从SpringBoot 2.2.2开始，带有Jackson（2.10.1）的自定义分页序列化程序不起作用，并且在序列化时不执行。

/**
 * This class allows to specify configuration related to the Web MVC part.
 */
@Configuration
public class WebConfiguration implements WebMvcConfigurer {

    private static final String JSON_DATA_PROPERTY = "data";

    /**
     * Allows to configure a {@link JsonSerializer} for pagination.
     *
     * @return an instance of {@link Module}.
     */
    @SuppressWarnings("rawtypes")
    @Bean
    public Module springDataPageModule() {
        return new SimpleModule().addSerializer(Page.class,new JsonSerializer<Page>() {
            @Override
            public void serialize(final Page page,final JsonGenerator jsonGenerator,final SerializerProvider serializers) throws IOException {

                jsonGenerator.writeStartObject();
                jsonGenerator.writeObjectField(JSON_DATA_PROPERTY,page.getcontent());
                jsonGenerator.writeObjectFieldStart("paging");
                jsonGenerator.writeNumberField("page",page.getNumber() + 1);
                jsonGenerator.writeNumberField("totalPages",page.getTotalPages());
                jsonGenerator.writeNumberField("totalElements",page.getTotalElements());
                jsonGenerator.writeNumberField("perPage",page.getSize());
                jsonGenerator.writeEndObject();
                jsonGenerator.writeEndObject();
            }
        });
    }
...
}

在SpringBoot 2.2.1中，此自定义分页序列化程序已应用并可以工作。你看到这个问题了吗？

自SpringBoot 2.2.2起，行为已更改。您必须完成模块的注册

/**
 * This class allows to specify configuration related to the Web MVC part.
 */
@Configuration
public class WebConfiguration implements WebMvcConfigurer {

    private static final String JSON_DATA_PROPERTY = "data";

    /**
     * Allows to configure a {@link JsonSerializer} for pagination.
     *
     * @return an instance of {@link Module}.
     */
    private Module preparePageModule() {
        return new SimpleModule().addSerializer(Page.class,new JsonSerializer<>() {
            @Override
            public void serialize(@SuppressWarnings("rawtypes") final Page page,final JsonGenerator jsonGenerator,final SerializerProvider serializers) throws IOException {

                jsonGenerator.writeStartObject();
                jsonGenerator.writeObjectField(JSON_DATA_PROPERTY,page.getContent());
                jsonGenerator.writeObjectFieldStart("paging");
                jsonGenerator.writeNumberField("page",page.getNumber() + 1);
                jsonGenerator.writeNumberField("totalPages",page.getTotalPages());
                jsonGenerator.writeNumberField("totalElements",page.getTotalElements());
                jsonGenerator.writeNumberField("perPage",page.getSize());
                jsonGenerator.writeEndObject();
                jsonGenerator.writeEndObject();
            }
        });
    }

    /**
     * Allows to configure the Jackson object mapper.
     *
     * @param objectMapper
     *            an instance of {@link ObjectMapper}.
     */
    @Autowired
    public void configureJacksonObjectMapper(final ObjectMapper objectMapper) {
        ...
        objectMapper.registerModule(preparePageModule());
    }
...
}
`

SpringBoot 2.2.2：用于自定义分页的Jackson序列化器不起作用

zhurouxia 回答：SpringBoot 2.2.2：用于自定义分页的Jackson序列化器不起作用

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