定义注解

package com.zspearl.cloud.common.core.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;


/**
 * <p>Title: 注解类：mybatis自定义主键生成策略</p>
 * <p>Description: </p>
 * @author cwh
 * @date 2022-11-16
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface AutoId {

    String primarkey() default "";

    IdType type() default IdType.SNOWFLAKE_ID;

    enum IdType {
        SNOWFLAKE_ID
    }
}

package com.zspearl.cloud.common.core.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CreateBy {

}

package com.zspearl.cloud.common.core.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CreateTime {

}

package com.zspearl.cloud.common.core.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface UpdateBy {
}

package com.zspearl.cloud.common.core.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface UpdateTime {
}

拦截器实现

package com.zspearl.cloud.goldstreet.config.interceptor;

import com.zspearl.cloud.common.core.annotation.*;
import com.zspearl.cloud.common.core.utils.DateUtils;
import com.zspearl.cloud.common.core.utils.IdUtils;
import com.zspearl.cloud.common.core.utils.StringUtils;
import com.zspearl.cloud.common.security.service.TokenService;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMap;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ReflectionUtils;

import java.lang.reflect.Field;
import java.util.Date;

/**
 * <p>Title: mybatis拦截器</p>
 * <p>Description: </p>
 * @author cwh
 * @date 2022.11.16 10:56
 */
@Component
@Intercepts(@Signature(type = Executor.class,method = "update",args = {MappedStatement.class,Object.class}))
public class MybatisInterceptor implements Interceptor {


    private Logger logger = LoggerFactory.getLogger(MybatisInterceptor.class);

    @Override
    public Object intercept(Invocation invocation) throws Throwable
    {
	/获取登录用户id
        Long userId = *********;
        if (StringUtils.isNull(userId))
        {
            userId = -1L;
        }

        Object[] args = invocation.getArgs();
        MappedStatement arg = (MappedStatement) args[0];
        if (SqlCommandType.INSERT.name().equals(arg.getSqlCommandType().name()))
        {
            ParameterMap parameter = arg.getParameterMap();
            Class<?> entityClass = parameter.getType();
            if (StringUtils.isNull(entityClass))
            {
                return invocation.proceed();
            }
            Long finalUserId = userId;
            ReflectionUtils.doWithFields(entityClass, field->{
                ReflectionUtils.makeAccessible(field);
                AutoId annotation = field.getAnnotation(AutoId.class);
                CreateTime createTime = field.getAnnotation(CreateTime.class);
                CreateBy createBy = field.getAnnotation(CreateBy.class);
                if (!ObjectUtils.isEmpty(annotation) && field.getType().isAssignableFrom(Long.class))
                {
                    field.setAccessible(true);
                    Object value = field.get(args[1]);
                    if (StringUtils.isNotNull(value)) {
                        return;
                    }
                    setField(args[1],field, generateId(annotation.type()));
                }
                else if (!ObjectUtils.isEmpty(createTime) && field.getType().isAssignableFrom(Date.class))
                {
                    setField(args[1], field, DateUtils.getNowDate());

                }
                else if (!ObjectUtils.isEmpty(createBy))
                {
                    if (field.getType().isAssignableFrom(String.class))
                    {
                        setField(args[1], field, String.valueOf(finalUserId));
                    }
                    else if (field.getType().isAssignableFrom(Long.class))
                    {
                        setField(args[1], field, finalUserId);
                    }

                }
            });
        }
        else if (SqlCommandType.UPDATE.name().equals(arg.getSqlCommandType().name()))
        {
            ParameterMap parameter = arg.getParameterMap();
            Class<?> entityClass = parameter.getType();
            if (StringUtils.isNull(entityClass))
            {
                return invocation.proceed();
            }
            Long finalUserId = userId;
            ReflectionUtils.doWithFields(entityClass, field->{
                ReflectionUtils.makeAccessible(field);
                if (!ObjectUtils.isEmpty(field.getAnnotation(UpdateTime.class)))
                {
                    setField(args[1], field, DateUtils.getNowDate());

                }
                if (!ObjectUtils.isEmpty(field.getAnnotation(UpdateBy.class)))
                {
                    if (field.getType().isAssignableFrom(Long.class))
                    {
                        setField(args[1], field, finalUserId);
                    }
                    else if (field.getType().isAssignableFrom(String.class))
                    {
                        setField(args[1], field, String.valueOf(finalUserId));
                    }

                }
            });
        }
        return invocation.proceed();
    }

    @Override
    public Object plugin(Object target)
    {
        return target instanceof Executor ? Plugin.wrap(target, this) : target;
    }

    protected Object generateId(AutoId.IdType type)
    {
        Object id = null;
        switch (type)
        {
            case SNOWFLAKE_ID:
		//雪花ID生成
                id = *****;
                break;
        }
        return id;
    }

    protected void setField(Object target, Field field, Object attributeValue) throws IllegalAccessException
    {
        field.setAccessible(true);
        field.set(target,attributeValue);
    }
}