MybatisPlus实现数据权限隔离的示例详解

<properties>
    <mybatis-plus.version>3.5.3.2</mybatis-plus.version>
</properties>

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>${mybatis-plus.version}</version>
</dependency>

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

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyDataScope {
    /**
     * 表别名设置
     */
    String alias() default "";
    
    /**
     * 数据权限表字段名
     */
    String dataId() default "";
}

import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.handler.DataPermissionHandler;
import com.itguoguo.annotation.MyDataScope;
import com.itguoguo.system.api.model.LoginUser;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;

import java.lang.reflect.Method;
import java.util.Objects;

import static com.itguoguo.utils.LoginUserUtils.getLoginUser;

@Slf4j
public class MyDataScopeHandler implements DataPermissionHandler {
    /**
     * 获取数据权限 SQL 片段表达式
     * @param where             待执行 SQL Where 条件表达式
     * @param mappedStatementId Mybatis MappedStatement Id 根据该参数可以判断具体执行方法
     * @return 数据权限 SQL 片段表达式
     */
    @Override
    public Expression getSqlSegment(Expression where, String mappedStatementId) {
        try {
            String className = mappedStatementId.substring(0, mappedStatementId.lastIndexOf("."));
            String methodName = mappedStatementId.substring(mappedStatementId.lastIndexOf(".") + 1);
            Method[] methods = Class.forName(className).getMethods();
            for (Method m : methods) {
                if (StrUtil.isBlank(m.getName()) || !m.getName().equals(methodName)) {
                    continue;
                }
                MyDataScope annotation = m.getAnnotation(MyDataScope.class);
                if (Objects.isNull(annotation)) {
                    return where;
                }
                String sqlSegment = getSqlSegment(annotation);
                return StrUtil.isBlank(sqlSegment) ? where : getExpression(where, sqlSegment);
            }
        } catch (ClassNotFoundException e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }

    /**
     * 拼接需要在业务 SQL 中额外追加的数据权限 SQL
     * @param annotation
     * @return 数据权限 SQL
     */
    private String getSqlSegment(MyDataScope annotation) {
        LoginUser loginUser = getLoginUser();
        String userType = loginUser.getSysUser().getUserType();
        Long userId = loginUser.getSysUser().getUserId();
        String sqlSegment = "";
        if (StrUtil.isBlank(userType)) {
            return sqlSegment;
        }
        if ("0".equals(userType)) {
            return sqlSegment;
        } else {
            sqlSegment = StrUtil.format(" {}.{} IN (SELECT project_id FROM sys_user where user_id = '{}') ",
                    annotation.alias(), annotation.dataId(), userId);
        }
        return sqlSegment;
    }

    /**
     * 将数据权限 SQL 语句追加到数据权限 SQL 片段表达式里
     * @param where         待执行 SQL Where 条件表达式
     * @param sqlSegment    数据权限 SQL 片段
     * @return
     */
    private Expression getExpression(Expression where, String sqlSegment) {
        try {
            Expression sqlSegmentExpression = CCJSqlParserUtil.parseCondExpression(sqlSegment);
            return (null != where) ? new AndExpression(where, sqlSegmentExpression) : sqlSegmentExpression;
        } catch (JSQLParserException e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }
}

import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.DataPermissionInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new DataPermissionInterceptor(new MyDataScopeHandler()));
        return interceptor;
    }
}

public interface MyMapper {
    @MyDataScope(alias = "a", dataId = "id")
    List findList();
}