SpringBoot配置文件读取顺序（看这一篇就够了）

解决LocalDateTime序列化问题

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;


@Configuration
public class JsonSerializationConfigurer {

    public static final String PATTERN = "yyyy-MM-dd HH:mm:ss";

    public static final DateTimeFormatter DATE_TIME = DateTimeFormatter.ofPattern(PATTERN);

    @Bean
    public ObjectMapper objectMapper() {
        return new ObjectMapper()
                .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
                .setDateFormat(new SimpleDateFormat(PATTERN))
                .registerModule(new SimpleModule()
                        .addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DATE_TIME))
                        .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DATE_TIME))
                        .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer2())
                        .addSerializer(Long.class, new CustomNumberSerializer())
                );
    }

    
    public static class CustomNumberSerializer extends JsonSerializer {
        @Override
        public void serialize(Number value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            ToStringSerializer.instance.serialize(value, gen, serializers);
        }
    }

    public static class LocalDateTimeDeserializer2 extends JsonDeserializer {

        @Override
        public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext) throws IOException {
            long timestamp = p.getValueAsLong();
            if (timestamp > 0) {
                return LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneId.systemDefault());
            } else {
                return null;
            }
        }
    }

}