Mybatis拦截器实现数据权限详解
作者：chaojunma
这篇文章主要介绍了Mybatis拦截器实现数据权限详解, 通过Mybatis拦截器我们可以拦截某些方法的调用,我们可以选择在这些被拦截的方法执行前后加上某些逻辑,需要的朋友可以参考下
前言
在我们日常开发过程中，通常会涉及到数据权限问题，下面以我们常见的一种场景举例：
一个公司有很多部门，每个人所处的部门和角色也不同，所以数据权限也可能不同，比如超级管理员可以查看某张表的素有信息，部门领导可以查看该部门下的相关信息，部门普通人员只可以查看个人相关信息，而且由于角色的不同，各个角色所能查看到的数据库字段也可能不相同，那么此处就涉及到了数据权限相关的问题。
那么我们该如何处理数据权限相关的问题呢？
我们提供一种通过Mybatis拦截器实现的方式，下面我们来具体实现一下
具体实现
pom.xml依赖
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.13.RELEASE</version>
</parent>
<properties>
<java.version>1.8</java.version>
<mybatis-plus.version>3.2.0</mybatis-plus.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>${mybatis-plus.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>application.yml文件
server:
port: 80
spring:
application:
name: data-scope
datasource:
url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTC
username: root
password: 123456
druid:
# 验证连接是否有效。此参数必须设置为非空字符串，下面三项设置成true才能生效
validation-query: SELECT 1
# 连接是否被空闲连接回收器(如果有)进行检验. 如果检测失败, 则连接将被从池中去除
test-while-idle: true
# 是否在从池中取出连接前进行检验, 如果检验失败, 则从池中去除连接并尝试取出另一个
test-on-borrow: true
# 是否在归还到池中前进行检验
test-on-return: false
# 连接在池中最小生存的时间，单位是毫秒
min-evictable-idle-time-millis: 30000
#mybatis配置
mybatis-plus:
type-aliases-package: com.mk.entity
mapper-locations: classpath:mapper/**/*.xml
global-config:
db-config:
id-type: auto
field-strategy: not_empty
logic-delete-value: 1
logic-not-delete-value: 0
configuration:
map-underscore-to-camel-case: true
cache-enabled: false
call-setters-on-nulls: true
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl代码实现
DataScode.java
@Data
public class DataScope {
// sql过滤条件
String sqlCondition;
// 需要过滤的结果字段
String[] filterFields;
}MybatisPlusConfig.java
@Configuration
public class MybatisPlusConfig {
@Bean
@ConditionalOnMissingBean
public DataScopeInterceptor dataScopeInterceptor() {
return new DataScopeInterceptor();
}
@Bean
public PaginationInterceptor paginationInterceptor() {
PaginationInterceptor page = new PaginationInterceptor();
page.setDialectType(DbType.MYSQL.getDb());
return page;
}
@Bean
public ConfigurationCustomizer mybatisConfigurationCustomizer(){
return new ConfigurationCustomizer() {
@Override
public void customize(MybatisConfiguration configuration) {
configuration.setObjectWrapperFactory(new MybatisMapWrapperFactory());
}
};
}
}DataScopeInterceptor.java
@Slf4j
@Intercepts({@Signature(type = Executor.class, method = "query",
args = {MappedStatement.class, Object.class, RowBounds.class,ResultHandler.class})})
public class DataScopeInterceptor implements Interceptor {
@Override
public Object intercept(Invocation invocation) throws Throwable {
log.info("执行intercept方法：{}", invocation.toString());
Object[] args = invocation.getArgs();
MappedStatement ms = (MappedStatement) args[0];
Object parameterObject = args[1];
// 查找参数中包含DataScope类型的参数
DataScope dataScope = findDataScopeObject(parameterObject);
if (dataScope == null) {
return invocation.proceed();
}
if (!ObjectUtils.isEmpty(dataScope.getSqlCondition())) {
// id为执行的mapper方法的全路径名，如com.mapper.UserMapper
String id = ms.getId();
// sql语句类型 select、delete、insert、update
String sqlCommandType = ms.getSqlCommandType().toString();
// 仅拦截 select 查询
if (!sqlCommandType.equals(SqlCommandType.SELECT.toString())) {
return invocation.proceed();
}
BoundSql boundSql = ms.getBoundSql(parameterObject);
String origSql = boundSql.getSql();
log.info("原始SQL: {}", origSql);
// 组装新的 sql
String newSql = String.format("%s%s%s%s", "select * from (", origSql, ") ", dataScope.getSqlCondition());
// 重新new一个查询语句对象
BoundSql newBoundSql = new BoundSql(ms.getConfiguration(), newSql,
boundSql.getParameterMappings(), boundSql.getParameterObject());
// 把新的查询放到statement里
MappedStatement newMs = newMappedStatement(ms, new BoundSqlSqlSource(newBoundSql));
for (ParameterMapping mapping : boundSql.getParameterMappings()) {
String prop = mapping.getProperty();
if (boundSql.hasAdditionalParameter(prop)) {
newBoundSql.setAdditionalParameter(prop, boundSql.getAdditionalParameter(prop));
}
}
Object[] queryArgs = invocation.getArgs();
queryArgs[0] = newMs;
log.info("改写的SQL: {}", newSql);
}
Object result = invocation.proceed();
return handleReslut(result, Arrays.asList(dataScope.getFilterFields()));
}
/**
* 定义一个内部辅助类，作用是包装 SQL
*/
class BoundSqlSqlSource implements SqlSource {
private BoundSql boundSql;
public BoundSqlSqlSource(BoundSql boundSql) {
this.boundSql = boundSql;
}
public BoundSql getBoundSql(Object parameterObject) {
return boundSql;
}
}
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) {
builder.keyProperty(ms.getKeyProperties()[0]);
}
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();
}
@Override
public Object plugin(Object target) {
log.info("plugin方法：{}", target);
if (target instanceof Executor) {
return Plugin.wrap(target, this);
}
return target;
}
@Override
public void setProperties(Properties properties) {
// 获取属性
// String value1 = properties.getProperty("prop1");
log.info("properties方法：{}", properties.toString());
}
/**
* 查找参数是否包括DataScope对象
*
* @param parameterObj 参数列表
* @return DataScope
*/
private DataScope findDataScopeObject(Object parameterObj) {
if (parameterObj instanceof DataScope) {
return (DataScope) parameterObj;
} else if (parameterObj instanceof Map) {
for (Object val : ((Map<?, ?>) parameterObj).values()) {
if (val instanceof DataScope) {
return (DataScope) val;
}
}
}
return null;
}
public Object handleReslut(Object returnValue, List<String> filterFields){
if(returnValue != null && !ObjectUtils.isEmpty(filterFields)){
if (returnValue instanceof ArrayList<?>){
List<?> list = (ArrayList<?>) returnValue;
List<Object> newList = new ArrayList<Object>();
if (1 <= list.size()) {
for(Object object:list){
if (object instanceof Map) {
Map map = (Map) object;
for (String key : filterFields) {
map.remove(key);
}
newList.add(map);
} else {
newList.add(decrypt(filterFields, object));
}
}
returnValue = newList;
}
} else {
if (returnValue instanceof Map) {
Map map = (Map) returnValue;
for (String key : filterFields) {
map.remove(key);
}
} else {
returnValue = decrypt(filterFields, returnValue);
}
}
}
return returnValue;
}
public static <T> T decrypt(List<String> filterFields, T t) {
Field[] declaredFields = t.getClass().getDeclaredFields();
try {
if (declaredFields != null && declaredFields.length > 0) {
for (Field field : declaredFields) {
if (filterFields.contains(field.getName())) {
field.setAccessible(true);
field.set(t, null);
field.setAccessible(false);
}
}
}
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
return t;
}
}SalariesMapper.xml
<mapper namespace="com.mk.mapper.SalariesMapper">
<select id="pageList" resultType="com.mk.entity.Salaries">
SELECT * from salaries where salary between #{start} and #{end}
</select>
<select id="getByEmpNo" resultType="java.util.Map">
select * from salaries where emp_no = #{empNo} limit 0,1
</select>
</mapper>SalariesMapper.java
@Mapper
public interface SalariesMapper extends BaseMapper<Salaries> {
List<Salaries> pageList(DataScope dataScope, @Param("start") int start, @Param("end") int end, Page<Salaries> page);
Map<String, Object> getByEmpNo(DataScope dataScope, @Param("empNo") int empNo);
}SalariesService.java
@Service
public class SalariesService extends ServiceImpl<SalariesMapper, Salaries> {
@Autowired
private SalariesMapper salariesMapper;
public List<Salaries> getList(){
Page<Salaries> page = new Page<>(1, 10);
DataScope dataScope = new DataScope();
// 设置查询条件
dataScope.setSqlCondition("s where 1=1 and s.emp_no = '10001'");
// 将结果集过滤掉salary和toDate字段
dataScope.setFilterFields(new String[]{"salary", "toDate"});
return salariesMapper.pageList(dataScope, 60000, 70000, page);
}
public Map<String, Object> getByEmpNo() {
DataScope dataScope = new DataScope();
// 将结果集过滤掉salary和toDate字段
dataScope.setFilterFields(new String[]{"salary", "toDate"});
return salariesMapper.getByEmpNo(dataScope, 10001);
}
}启动服务，执行相关操作，sql在执行之前会执行DataScopeInterceptor拦截器中的逻辑，从而改变sql，具体的相关操作就是将原来的sql语句origSql在外层包装一层过滤条件，如：select * from (origSql) 过滤条件，此处的过滤条件要封装到DataScope对象中
例如：
dataScope.setSqlCondition("s where 1=1 and s.emp_no = '10001'")
那么在经过拦截器处理以后要执行的sql语句为
select * from (origSql) s where 1=1 and s.emp_no = '10001'
从而实现数据权限相操作，当然此处的过滤条件只是为了演示效果举的一个例子
而已，在实际开发过程中要根据用户角色等等设置具体的过滤条件。
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