实现自定义序列化和反序列化控制的5种方式

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.module.SimpleModule;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class CustomDateSerializationExample {

    public static class DateSerializer extends JsonSerializer<Date> {
        private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");

        @Override
        public void serialize(Date value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            String formattedDate = DATE_FORMAT.format(value);
            gen.writeString(formattedDate);
        }
    }

    public static class DateDeserializer extends JsonDeserializer<Date> {
        private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");

        @Override
        public Date deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
            String dateString = p.getText();
            try {
                return DATE_FORMAT.parse(dateString);
            } catch (Exception e) {
                throw new IOException("Failed to parse date: " + dateString, e);
            }
        }
    }

    public static class Person {
        private String name;
        private Date birthDate;

        // 省略构造函数和getter/setter方法
    }

    public static void main(String[] args) throws Exception {
        SimpleModule module = new SimpleModule();
        module.addSerializer(Date.class, new DateSerializer());
        module.addDeserializer(Date.class, new DateDeserializer());

        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.registerModule(module);

        // 序列化示例
        Person person = new Person("John Doe", new SimpleDateFormat("yyyy-MM-dd").parse("2000-01-01"));
        String json = objectMapper.writeValueAsString(person);
        System.out.println(json);  // 输出结果：{"name":"John Doe","birthDate":"2000-01-01"}

        // 反序列化示例
        String jsonInput = "{\"name\":\"Jane Smith\",\"birthDate\":\"1990-12-31\"}";
        Person deserializedPerson = objectMapper.readValue(jsonInput, Person.class);
        System.out.println(deserializedPerson.getBirthDate());  // 输出结果：Sat Dec 31 00:00:00 GMT 1990
    }
}