Spring Boot 之使用 Json 详解

@ResponseBody
@RequestMapping(name = "/getInfo", method = RequestMethod.GET)
public InfoDTO getInfo() {
    return new InfoDTO();
}

@RequestMapping(name = "/postInfo", method = RequestMethod.POST)
public void postInfo(@RequestBody InfoDTO infoDTO) {
    // ...
}

import java.io.*;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import org.springframework.boot.jackson.*;

@JsonComponent
public class Example {

    public static class Serializer extends JsonSerializer<SomeObject> {
        // ...
    }

    public static class Deserializer extends JsonDeserializer<SomeObject> {
        // ...
    }

}

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration org.springframework.boot.test.autoconfigure.json.JsonTestersAutoConfiguration

@JsonTest
@RunWith(SpringRunner.class)
public class SimpleJsonTest {

    private final Logger log = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private JacksonTester<InfoDTO> json;

    @Test
    public void testSerialize() throws Exception {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        InfoDTO infoDTO = new InfoDTO("JSON测试应用", "1.0.0", sdf.parse("2019-01-01 12:00:00"));
        JsonContent<InfoDTO> jsonContent = json.write(infoDTO);
        log.info("json content: {}", jsonContent.getJson());
        // 或者使用基于JSON path的校验
        assertThat(jsonContent).hasJsonPathStringValue("@.appName");
        assertThat(jsonContent).extractingJsonPathStringValue("@.appName").isEqualTo("JSON测试应用");
        assertThat(jsonContent).hasJsonPathStringValue("@.version");
        assertThat(jsonContent).extractingJsonPathStringValue("@.version").isEqualTo("1.0.0");
        assertThat(jsonContent).hasJsonPathStringValue("@.date");
        assertThat(jsonContent).extractingJsonPathStringValue("@.date").isEqualTo("2019-01-01 12:00:00");
    }

    @Test
    public void testDeserialize() throws Exception {
        String content = "{\"appName\":\"JSON测试应用\",\"version\":\"1.0.0\",\"date\":\"2019-01-01\"}";
        InfoDTO actual = json.parseObject(content);
        assertThat(actual.getAppName()).isEqualTo("JSON测试应用");
        assertThat(actual.getVersion()).isEqualTo("1.0.0");
    }
}

spring.jackson.date-format= # Date format string or a fully-qualified date format class name. For instance, `yyyy-MM-dd HH:mm:ss`.
spring.jackson.default-property-inclusion= # Controls the inclusion of properties during serialization. Configured with one of the values in Jackson's JsonInclude.Include enumeration.
spring.jackson.deserialization.*= # Jackson on/off features that affect the way Java objects are deserialized.
spring.jackson.generator.*= # Jackson on/off features for generators.
spring.jackson.joda-date-time-format= # Joda date time format string. If not configured, "date-format" is used as a fallback if it is configured with a format string.
spring.jackson.locale= # Locale used for formatting.
spring.jackson.mapper.*= # Jackson general purpose on/off features.
spring.jackson.parser.*= # Jackson on/off features for parsers.
spring.jackson.property-naming-strategy= # One of the constants on Jackson's PropertyNamingStrategy. Can also be a fully-qualified class name of a PropertyNamingStrategy subclass.
spring.jackson.serialization.*= # Jackson on/off features that affect the way Java objects are serialized.
spring.jackson.time-zone= #  Time zone used when formatting dates. For instance, "America/Los_Angeles" or "GMT+10".
spring.jackson.visibility.*= # Jackson visibility thresholds that can be used to limit which methods (and fields) are auto-detected.

spring.gson.date-format= # Format to use when serializing Date objects.
spring.gson.disable-html-escaping= # Whether to disable the escaping of HTML characters such as '<', '>', etc.
spring.gson.disable-inner-class-serialization= # Whether to exclude inner classes during serialization.
spring.gson.enable-complex-map-key-serialization= # Whether to enable serialization of complex map keys (i.e. non-primitives).
spring.gson.exclude-fields-without-expose-annotation= # Whether to exclude all fields from consideration for serialization or deserialization that do not have the "Expose" annotation.
spring.gson.field-naming-policy= # Naming policy that should be applied to an object's field during serialization and deserialization.
spring.gson.generate-non-executable-json= # Whether to generate non executable JSON by prefixing the output with some special text.
spring.gson.lenient= # Whether to be lenient about parsing JSON that doesn't conform to RFC 4627.
spring.gson.long-serialization-policy= # Serialization policy for Long and long types.
spring.gson.pretty-printing= # Whether to output serialized JSON that fits in a page for pretty printing.
spring.gson.serialize-nulls= # Whether to serialize null fields.

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.54</version>
</dependency>

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    private final Logger log = LoggerFactory.getLogger(this.getClass());

    /**
     * 自定义消息转换器
     * @param converters
     */
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        // 清除默认 Json 转换器
        converters.removeIf(converter -> converter instanceof MappingJackson2HttpMessageConverter);

        // 配置 FastJson
        FastJsonConfig config = new FastJsonConfig();
        config.setSerializerFeatures(SerializerFeature.QuoteFieldNames, SerializerFeature.WriteEnumUsingToString,
            SerializerFeature.WriteMapNullValue, SerializerFeature.WriteDateUseDateFormat,
            SerializerFeature.DisableCircularReferenceDetect);

        // 添加 FastJsonHttpMessageConverter
        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
        fastJsonHttpMessageConverter.setFastJsonConfig(config);
        List<MediaType> fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        fastJsonHttpMessageConverter.setSupportedMediaTypes(fastMediaTypes);
        converters.add(fastJsonHttpMessageConverter);

        // 添加 StringHttpMessageConverter，解决中文乱码问题
        StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        converters.add(stringHttpMessageConverter);
    }

    // ...
}