mybatis-plus实现对创建时间和更新时间的自动填充

import com.baomidou.mybatisplus.core.config.GlobalConfig;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
public class MybatisPlusConf {
    /**
     * 自动填充功能
     */
    @Bean
    public GlobalConfig globalConfig() {
        GlobalConfig globalConfig = new GlobalConfig();
        globalConfig.setMetaObjectHandler(new MetaHandler());
        return globalConfig;
    }

}

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.util.Date;


@Component
public class MetaHandler implements MetaObjectHandler {

    /**
     * 新增数据执行
     */
    @Override
    public void insertFill(MetaObject metaObject) {
        boolean hasSetter = metaObject.hasSetter("createTime");
        if (hasSetter) {
            this.setFieldValByName("createTime", new Date(), metaObject);
            this.setFieldValByName("updateTime", new Date(), metaObject);
        }
    }

    /**
     * 更新数据执行
     */
    @Override
    public void updateFill(MetaObject metaObject) {
        Object val = getFieldValByName("updateTime", metaObject);
        if (val == null) {
            this.setFieldValByName("updateTime", new Date(), metaObject);
        }
    }

}

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Timestamp;
import java.time.LocalDateTime;

import org.apache.ibatis.binding.MapperMethod.ParamMap;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Signature;
import org.springframework.stereotype.Component;


@Component
@Intercepts({ @Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }) })
public class CreateTimeSetInterceptor implements Interceptor {

	private static final String CREATE_TIME_SETTER = "setCreateTime";
	private static final String UPDATE_TIME_SETTER = "setUpdateTime";

	@Override
	public Object intercept(Invocation invocation) throws Throwable {
		MappedStatement ms = (MappedStatement) invocation.getArgs()[0];
		Object parameter = invocation.getArgs()[1];

		if (ms.getSqlCommandType() == SqlCommandType.INSERT) {
			setTimeIfNeccesary(parameter, CREATE_TIME_SETTER);
			setTimeIfNeccesary(parameter, UPDATE_TIME_SETTER);
		} else if (ms.getSqlCommandType() == SqlCommandType.UPDATE) {
			setTimeIfNeccesary(parameter, UPDATE_TIME_SETTER);
		}
		return invocation.getMethod().invoke(invocation.getTarget(), invocation.getArgs());
	}

	private void setTimeIfNeccesary(Object param, String methodName) {
		Class<?> cls = param.getClass();

		if (cls == ParamMap.class) {
			@SuppressWarnings("unchecked")
			ParamMap<Object> map = (ParamMap<Object>) param;
			map.entrySet().forEach(entry -> {
				if (!entry.getKey().equals("et")) {
					setIfSetterExist(entry.getValue(), methodName);
				}
			});
		} else {
			setIfSetterExist(param, methodName);
		}
	}

	private void setIfSetterExist(Object param, String methodName) {
		Class<?> cls = param.getClass();
		try {
			Method m = null;
			try {
				m = cls.getDeclaredMethod(methodName, new Class[] { LocalDateTime.class });
				if (m != null) {
					m.setAccessible(true);
					m.invoke(param, LocalDateTime.now());
				}
			} catch (NoSuchMethodException e1) {
				m = cls.getDeclaredMethod(methodName, new Class[] { Timestamp.class });
				if (m != null) {
					m.setAccessible(true);
					m.invoke(param, new Timestamp(System.currentTimeMillis()));
				}
			}
		} catch (NoSuchMethodException | SecurityException | IllegalAccessException | IllegalArgumentException
				| InvocationTargetException e) {
			e.printStackTrace();
		}
	}

}