帮我写一个 LocalDateTime 序列化反序列化 的全局配置类

好的，以下是一个简单的 LocalDateTime 序列化反序列化的全局配置类示例：

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

import java.time.LocalDateTime;

@Configuration
public class LocalDateTimeConfig {

    @Bean
    public ObjectMapper objectMapper(Jackson2ObjectMapperBuilder builder) {
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer());
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer());
        objectMapper.registerModule(javaTimeModule);
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        return objectMapper;
    }
}

在上面的代码中，我们首先创建了一个 `ObjectMapper` 对象，并添加了 `JavaTimeModule` 模块，该模块包含了序列化和反序列化 `LocalDateTime` 对象的方法。然后我们将此 `ObjectMapper` 注册到 Spring 的全局配置中，并关闭了时间戳的序列化。

接下来我们需要自定义 `LocalDateTimeSerializer` 和 `LocalDateTimeDeserializer` 类来实现 `LocalDateTime` 的序列化和反序列化：

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {

    private static final DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;

    @Override
    public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        gen.writeString(formatter.format(value));
    }
}

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {

    private static final DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;

    @Override
    public LocalDateTime deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        return LocalDateTime.parse(p.getValueAsString(), formatter);
    }
}

现在，我们就可以使用 `LocalDateTime` 类型的属性在 RESTful API 中进行序列化和反序列化了。