Spring-MyBatis-SQL拦截

时间 2019-11-17

原文原文链接

1、应用场景

在项目中，针对敏感数据等重要数据的列表查询，为避免数据泄露等，须要针对数据添加权限。java

场景：有三个帐号：员工A、员工B、经理A；专员A、B 属于经理A的下级，且他们属于同一部门；在数据库中的客户列表中，员工A、B只能查看本身服务的客户列表，经理A能够查看该部门的客户列表，不能查看其余部门的客户列表；在这中场景下，就须要应用到数据权限了。mysql

为了方便不影响其余业务编码，下降耦合，在底层SQL执行前拦截根据权限条件添加WHERE条件，进行动态更改SQLgit

2、Jar包准备（不用分页，不要也能够）

<dependency>
     <groupId>com.github.pagehelper</groupId>
     <artifactId>pagehelper</artifactId>
     <version>5.1.8</version>
</dependency>

3、编码准备

package com.richfun.boot.common.config;

import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.mapping.SqlSource;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.springframework.stereotype.Component;

import java.util.Properties;

/**
 * MyBatis SQL拦截
 * @author geYang 2019-07-16
 * */
@Component
@Intercepts(@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}))
public class MBSqlInterceptor implements Interceptor {

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

    @Override
    public void setProperties(Properties properties) {}

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        String sqlType = getSqlType(invocation);
        if (!SELECT.equals(sqlType)) {
            return invocation.proceed();
        }
        String sqlId = getSqlId(invocation);
        System.out.println("SQL__ID: " + sqlId);
        String sql = getSql(invocation);
        System.out.println("原始SQL: " + sql);
        String updateSql = getUpdateSql(sql);
        System.out.println("查询SQL: " + updateSql);
        if (!sql.equals(updateSql)) {
            updateSql(invocation, updateSql);
        }
        return invocation.proceed();
    }

    /**
     * 拦截编辑后的SQL
     * */
    private String getUpdateSql(String sql) {
        StringBuilder updateSql = new StringBuilder(sql);
        // 各类数据权限拦截
        boolean is_where = sql.contains("WHERE") || sql.contains("where");
        if (is_where) {
            updateSql.append(" AND user_id > 1");
        } else {
            updateSql.append(" WHERE user_id > 1");
        }
        return updateSql.toString();
    }

    /**
     * 获取SQL类型
     * */
    private static final String SELECT = "SELECT", INSERT = "INSERT", UPDATE = "UPDATE", DELETE = "DELETE";
    private static String getSqlType(Invocation invocation) {
        final Object[] args = invocation.getArgs();
        MappedStatement ms = (MappedStatement) args[0];
        SqlCommandType commandType = ms.getSqlCommandType();
        if (commandType.compareTo(SqlCommandType.SELECT) == 0) { return SELECT; }
        if (commandType.compareTo(SqlCommandType.INSERT) == 0) { return INSERT; }
        if (commandType.compareTo(SqlCommandType.UPDATE) == 0) { return UPDATE; }
        if (commandType.compareTo(SqlCommandType.DELETE) == 0) { return DELETE; }
        return null;
    }
    /**
     * 获取SQL-ID
     * */
    private String getSqlId(Invocation invocation) {
        final Object[] args = invocation.getArgs();
        MappedStatement ms = (MappedStatement) args[0];
        return ms.getId();
    }
    /**
     * 获取SQL语句
     * */
    private String getSql(Invocation invocation) {
        final Object[] args = invocation.getArgs();
        MappedStatement ms = (MappedStatement) args[0];
        Object parameterObject = args[1];
        BoundSql boundSql = ms.getBoundSql(parameterObject);
        return boundSql.getSql();
    }

    /**
     * 修改SQL语句
     * */
    private void updateSql(Invocation invocation, String sql) {
        final Object[] args = invocation.getArgs();
        MappedStatement ms = (MappedStatement) args[0];
        Object parameterObject = args[1];
        BoundSql boundSql = ms.getBoundSql(parameterObject);
        MappedStatement newStatement = newMappedStatement(ms, new BoundSqlSqlSource(boundSql));
        MetaObject msObject = SystemMetaObject.forObject(newStatement);
        msObject.setValue("sqlSource.boundSql.sql", sql);
        args[0] = newStatement;
    }

    /**
     * SQL
     * */
    private MappedStatement newMappedStatement(MappedStatement ms, SqlSource newSqlSource) {
        MappedStatement.Builder builder = new MappedStatement.Builder(ms.getConfiguration(), ms.getId(), newSqlSource, ms.getSqlCommandType());
        builder.resource(ms.getResource());
        builder.fetchSize(ms.getFetchSize());
        builder.statementType(ms.getStatementType());
        builder.keyGenerator(ms.getKeyGenerator());
        if (ms.getKeyProperties() != null && ms.getKeyProperties().length != 0) {
            StringBuilder keyProperties = new StringBuilder();
            for (String keyProperty : ms.getKeyProperties()) {
                keyProperties.append(keyProperty).append(",");
            }
            keyProperties.delete(keyProperties.length() - 1, keyProperties.length());
            builder.keyProperty(keyProperties.toString());
        }
        builder.timeout(ms.getTimeout());
        builder.parameterMap(ms.getParameterMap());
        builder.resultMaps(ms.getResultMaps());
        builder.resultSetType(ms.getResultSetType());
        builder.cache(ms.getCache());
        builder.flushCacheRequired(ms.isFlushCacheRequired());
        builder.useCache(ms.isUseCache());
        return builder.build();
    }

    /**
     * SQL 绑定工具
     * */
    private class BoundSqlSqlSource implements SqlSource {
        private BoundSql boundSql;
        BoundSqlSqlSource(BoundSql boundSql) {
            this.boundSql = boundSql;
        }
        @Override
        public BoundSql getBoundSql(Object parameterObject) {
            return boundSql;
        }
    }

}

4、配置拦截器 mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <!-- 自定义SQL拦截, 执行顺序: 从下往上 -->
    <plugins>
        <!-- 分页拦截 （不用分页，不要也能够）-->
        <plugin interceptor="com.github.pagehelper.PageInterceptor">
            <property name="helperDialect" value="mysql"/>
        </plugin>
        <!-- SQL拦截 -->
        <plugin interceptor="com.gy.spring.mvc.common.interceptor.MBSqlInterceptor" />
    </plugins>

</configuration>

5、使用

@Test
    public void testDao() {
//        PageHelper.startPage(1, 10);
        List<Map<String, Object>> list = commonDao.list("UserMapper.listUser", null);
        System.out.println(list);
    }

6、总结

SQL拦截基于动态代理的方式来实现，只需实现 Interceptor 接口便可；github

7、分页文档资料

Mybatis-PageHelper： https://github.com/pagehelper/Mybatis-PageHelper spring

PageHelper拦截文档： https://pagehelper.github.io/docs/interceptor/sql