Java整合mybatis实现过滤数据
目录
- 场景
- 例子
- 执行流程
- 配置切面
- 方案
- 实现
场景
- 权限1:只能看到自己创建的数据
- 权限2:只能看到本部门的数据
- 权限3:查看全部数据
例子
小明有权限1:
{ "code": "200", "msg": "查询成功", "data": [ { "name": "name1", "id": "1", "creater": "xiaoming" }, { "name": "name2", www.devze.com "id": "2", "creater": "xiaoming" } ] }
大明具有权限2,小明相同部门
{ "code": "200", "msg": "查询成功", "data": [ { "name": "name1", "id": "1", "creater": "xiaoming" }, { "name": "name2", "id": "2", "creater": "xiaoming" }, { "name": "name3", "id": "3", "creater": "daming" }, { "name": "name4", "id": "4", "creater": "daming" } ] }
领导有权编程客栈限3,可以看到全部
{ "code": "200", "msg": "查询成功", "data": [ { "name": "name1", "id": "1", "creater": "xiaoming" }, { "name": "name2", "id": "2", "creater": "xiaoming" }, { "name": "name3", "id": "3", "creater": "daming" }, { "name": "name4", "id": "4", "creater": "daming" }, { "name": "name5", "id": "5", "creater": "mingming" } ] }
执行流程
- Configuration:初始化基础配置,比如 MyBATis 的别名等,一些重要的类型对象,如插件,映射器,ObjectFactory 和 TypeHandler对象, MyBatis所有的配置信息都维持在 Configuration 对象之中。
- SqlSessionFactory:SqlSession工厂。
- SqlSession:作为MyBatis工作的主要顶层API,表示和数据库交互的会话,完成必要的数据库增删改查功能。
- Executor:真正执行sql语句的对象,调用 sqlSession 的方法时,本质上都是调用 executor 的方法,还负责获取 connection,创建 StatementHandler ,责调用 StatementHandler 操作数据库 ,并把结果集通过 ResultSetHandler 进行自动映射,另外,它还处理二级缓存的操作。
- StatementHandler:可以理解为是一次语句的执行,创建并持有 ParameterHandler 和 ResultSetHandler 对象,操作 dbc 的statement与进行数据库操作,另外它也实现了MyBatis的一级缓存。
- ParameterHandler: 处理入参,将Java方法上的参数设置到被执行语句中
- ResultSetHandler:处理返回结果,处理jdbc的返回值,将其转换为java的对象
- TypeHandler:负责Java数据类型和JDBC数据类型之间的映射和转换,在 ParameterHandler 和 ResultsetHandler 中
- MappedStatement:MappedStatement维护了一条 <select|update|delete|insert> 节点的封装。
- SqlSource:负责根据用户传递的 parameterObject,动态地生成 SQL 语句,将信息封装到 BoundSql 对象中,并返回。
- BoundSql:表示动态生成的 SQL 语句以及相应的参数信息。
配置切面
- Interceptor: 实现 Interceptor 接口,mybatis 的拦截器
- @Intercepts:只有一个属性,即value,其返回值类型是一个@Signature类型的数组,表示我们可以配置多个@Signature注解
- @Signature:一个方法签名,其共有三个属性,分别为:type、method、args
- type:拦截的四种类型:Executor - 执行器方法 、StatementHandler - 拦截SQL语法构建处理、ParameterHandler - 拦截参数处理、ResultSetHandler - 拦截结果集处理
- method:对应接口中的某一个方法名,比如 Executor 的 query 方法
- args:对应接口中的某一个方法的参数,比如 Executor 中 query 方法因为重载原因,有多个,args就是指明参数类型,从而确定是具体哪一个方法;
@Intercepts({<!--{cke_protected}{C}%3C!%2D%2D%20%2D%2D%3E-->@Signature(type = org.apache.ibatis.executor.Executor.class, method = "query", args = {<!--{cke_protected}{C}%3C!%2D%2D%20%2D%2D%3E-->MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class})})@Slf4jpublic class MapperPermissionInterceptor implements Interceptor {<!--{cke_protected}{C}%3C!%2D%2D%20%2D%2D%3E--> @Override public Object intercept(Invocation invocation) throws Throwable {<!--{cke_protected}{C}%3C!%2D%2D%20%2D%2D%3E--> Object target = invocation.getTarget(); //被代理对象 Method method = invocation.getMethod(); //代理方法 Object[] args = invocation.getArgs(); //方法参数MappedStatement mappedStatement = (MappedStatement) args[0]; Object parameterObject = args[1]; // do something ...方法拦截前执行代码块 Object result = invocation.proceed(); // do something ...方法拦截后执行代码块 return result; } }@Intercepts({@Signature(type = org.apache.ibatis.executor.Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class})}) @Slf4j public class MapperPermissionInterceptor implements Interceptor { @Override public Object intercept(Invocation invocation) throws Throwable { Object target = invocation.getTarget(); //被代理对象 Method method = invocation.getMethod(); //代理方法 Object[] args = invocation.getArgs(); //方法参数 MappedStatement mappedStatement = (MappedStatement) args[0]; Object parameterObject = args[1]; // do something ...方法拦截前执行代码块 Object result = invocation.proceed(); // do something ...方法拦截后执行代码块 return result; } }
方案
原 originalSql
select id, name, creater from tt
通过 mybatis 的切面实现
在前面添加 select * from ( ,后面添加 where 条件
select * from ( select id, name, creater from tt ) tmp where creater = "daming"
实现
- 配置权限开关
- 判断方法名是否包含 list 或者 page
- 添加 where 条件
@Intercepts({@Signature(type = org.apache.ibatis.executor.Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class})}) @Slf4j public class MapperPermissionInterceptor implements Interceptor { @Autowired PermissionProperty permissionProperty; public static final String PACK_START_SQL = "select * from ( "; public static final Strhttp://www.devze.coming PACK_END_SQL = ") tmp "; public static final String PERMISSION_Y = "y"; @Override public Object intercept(Invocation invocation) throws Throwable { if(!PERMISSION_Y.toLowerCase().equals(permissionProperty.getMapper().toLowerCase(python))){ log.info("mapper 权限未开启"); return invocation.proceed(); } MappedStatement mapandroidpedStatement = (MappedStatement) invocation.getArgs()[0]; Object parameter = invocation.getArgs()[1]; BoundSql boundSql = mappedStatement.getBoundSql(parameter); Strin开发者_JAVAg originalSql = boundSql.getSql().trim(); String id = mappedStatement.getId(); log.info("originalSql: {} ", originalSql); log.info("id: {}", id); String name = getMapperName(id); String method = getMapperMethod(id); log.info("name: {}, method: {} ", name, method); String joinSql = dataPermissionSqlProvider().getJoinSql(name, method); log.info("joinSql: {} ", joinSql); if (Optional.ofNullable(joinSql).isPresent()) { BoundSql newBoundSql = copyFromBoundSql(mappedStatement, boundSql, this.joinSql(originalSql, joinSql)); ParameterMap map = mappedStatement.getParameterMap(); MappedStatement newMs = copyFromMappedStatement(mappedStatement, new BoundSqlSqlSource(newBoundSql), map); invocation.getArgs()[0] = newMs; } return invocation.proceed(); } /** * 获取 Mapper 名称 * @param id * @return */ private String getMapperName(String id) { String name = id.substring(0, id.lastIndexOf(".")); return name.substring(name.lastIndexOf(".") + 1); } /** * 获取 Mapper 方法 * @param id * @return */ private String getMapperMethod(String id) { String method = id.substring(id.lastIndexOf(".") + 1); return method; } private DataPermissionProvider dataPermissionSqlProvider() { return (DataPermissionProvider) ApplicationContextUtil.getBean("dataPermissionProvider"); } private String joinSql(String sql, String selectSql) { sql = PACK_START_SQL + sql + PACK_END_SQL + selectSql; log.info("packSql: {}", sql); return sql; } public static class BoundSqlSqlSource implements SqlSource { BoundSql boundSql; public BoundSqlSqlSource(BoundSql boundSql) { this.boundSql = boundSql; } @Override public BoundSql getBoundSql(Object parameterObject) { return boundSql; } } private BoundSql copyFromBoundSql(MappedStatement ms, BoundSql boundSql, String sql) { BoundSql newBoundSql = new BoundSql(ms.getConfiguration(), sql, boundSql.getParameterMappings(), boundSql.getParameterObject()); for (ParameterMapping mapping : boundSql.getParameterMappings()) { String prop = mapping.getProperty(); if (boundSql.hasAdditionalParameter(prop)) { newBoundSql.setAdditionalParameter(prop, boundSql.getAdditionalParameter(prop)); } } return newBoundSql; } /** * 复制MappedStatement对象 */ private MappedStatement copyFromMappedStatement(MappedStatement ms, SqlSource newSqlSource, ParameterMap parameterMap) { 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()); builder.timeout(ms.getTimeout()); builder.parameterMap(parameterMap); builder.resultMaps(ms.getResultMaps()); builder.resultSetType(ms.getResultSetType()); builder.cache(ms.getCache()); builder.flushCacheRequired(ms.isFlushCacheRequired()); builder.useCache(ms.isUseCache()); return builder.build(); } }
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