1、依赖导入

 		<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
        </dependency>

因为springBoot做了jar包版本管理，所以不需要引入version标签

2、application.yaml配置

spring.mvc.converters.preferred-json-mapper: gson

3、GsonConfig

@Configuration
public class GsonConfig {

    /**
     * 自定义gson配置
     */
    @Bean
    public GsonBuilderCustomizer customizer() {
        return b -> b
            .setLongSerializationPolicy(LongSerializationPolicy.STRING)
            .registerTypeAdapter(LocalDate.class, new LocalDateAdapter())
            .registerTypeAdapter(LocalDateTime.class, new LocalDateTimeAdapter())
            // The date format will be used to serialize and deserialize Date and in case the java.sql module is present, also java.sql
            // .Timestamp and java.sql.Date.
            .setDateFormat("yyyy-MM-dd HH:mm:ss")
            .serializeNulls()
            .create();
    }

    /**
     * 只有序列化功能
     */
    // public static class LocalDateTimeSerializer implements JsonSerializer<LocalDateTime> {
    //
    //     @Override
    //     public JsonElement serialize(LocalDateTime localDateTime, Type type, JsonSerializationContext jsonSerializationContext) {
    //         return new JsonPrimitive(localDateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
    //     }
    // }
    //
    // public static class LocalDateSerializer implements JsonSerializer<LocalDate> {
    //
    //     @Override
    //     public JsonElement serialize(LocalDate localDate, Type type, JsonSerializationContext jsonSerializationContext) {
    //         return new JsonPrimitive(localDate.format(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
    //     }
    // }

    public static class LocalDateAdapter extends TypeAdapter<LocalDate> {

        @Override
        public void write(final JsonWriter jsonWriter, final LocalDate localDate) throws IOException {
            if (localDate == null) {
                jsonWriter.nullValue();
            } else {
                jsonWriter.value(localDate.toString());
            }
        }

        @Override
        public LocalDate read(final JsonReader jsonReader) throws IOException {
            if (jsonReader.peek() == JsonToken.NULL) {
                jsonReader.nextNull();
                return null;
            } else {
                return LocalDate.parse(jsonReader.nextString());
            }
        }
    }

    public static class LocalDateTimeAdapter extends TypeAdapter<LocalDateTime> {

        @Override
        public void write(final JsonWriter jsonWriter, final LocalDateTime localDate) throws IOException {
            if (localDate == null) {
                jsonWriter.nullValue();
            } else {
                jsonWriter.value(localDate.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
            }
        }

        @Override
        public LocalDateTime read(final JsonReader jsonReader) throws IOException {
            if (jsonReader.peek() == JsonToken.NULL) {
                jsonReader.nextNull();
                return null;
            } else {
                return LocalDateTime.parse(jsonReader.nextString(), DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
            }
        }
    }
}

4、测试

@Data
public class Book {

    private Long id;
    private String name;

    //@JsonAdapter(value = GsonConfig.LocalDateAdapter.class)
    private LocalDate publishDate;
   //@JsonAdapter(value = GsonConfig.LocalDateTimeAdapter.class)
    private LocalDateTime createTime;
}

@RestController
@RequestMapping("/book")
public class IndexController {

    @PostMapping
    public Book save(@RequestBody Book book) {
        return book;
    }

    @GetMapping
    public Book get() {
        Book book = new Book();
        book.setId(1L);
        book.setName("tcoding");
        book.setCreateTime(LocalDateTime.now());
        book.setPublishDate(LocalDate.now());
        return book;
    }
}

curl 127.0.0.1:8080/book                  
{"id":"1","name":"tcoding","publishDate":"2022-09-10","createTime":"2022-09-10 15:32:17"}%

 curl -X POST 127.0.0.1:8080/book --header 'Content-Type: application/json'    --data-raw '{"id":"1","name":"tcoding","publishDate":"2022-09-10","createTime":"2022-09-10 15:32:17"}'                              
{"id":"1","name":"tcoding","publishDate":"2022-09-10","createTime":"2022-09-10 15:32:17"}%

5、 SpringBoot Gson自动配置流程

GsonAutoConfiguration

在这里插入图片描述

上面GsonConfig配置类里面

  @Bean
    public GsonBuilderCustomizer customizer() {
        return b -> b
            .setLongSerializationPolicy(LongSerializationPolicy.STRING)
            .registerTypeAdapter(LocalDate.class, new LocalDateAdapter())
            .registerTypeAdapter(LocalDateTime.class, new LocalDateTimeAdapter())
            // The date format will be used to serialize and deserialize Date and in case the java.sql module is present, also java.sql
            // .Timestamp and java.sql.Date.
            .setDateFormat("yyyy-MM-dd HH:mm:ss")
            .serializeNulls()
            .create();
    }