MyBatis 自定义 SQL 拦截器，java 数据可视化技术

2. 限制登录用户只能访问当前机构数据。

定义是否开启注解

========

定义是否开启注解, 主要做的一件事情就是是否添加 SQL 拦截器。

// 全局开启

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.TYPE)

@Documented

@Import(MyBatisSqlInterceptorConfiguration.class)

public @interface EnableSqlInterceptor {

}

// 自定义注解

@Target({ElementType.METHOD })

@Retention(RetentionPolicy.RUNTIME)

public @interface DataScope {

}

复制代码

注册 SQL 拦截器

=========

注册一个 SQL 拦截器，会对符合条件的 SQL 查询操作进行拦截。

public class MyBatisSqlInterceptorConfiguration implements ApplicationContextAware {

@Override

public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

SqlSessionFactory sqlSessionFactory = applicationContext.getBean(SqlSessionFactory.class);

sqlSessionFactory.getConfiguration().addInterceptor(new MyBatisInterceptor());

}

}

复制代码

处理逻辑

====

在处理逻辑中，我主要是做一个简单的 limit 1 案例，如果是自己需要做其他的逻辑需要修改

@Slf4j

@Intercepts(

{

@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}),

@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class, CacheKey.class, BoundSql.class}),

})

public class MyBatisInterceptor implements Interceptor {

private static final Logger LOGGER = LoggerFactory.getLogger(MyBatisInterceptor.class);

@Override

public Object intercept(Invocation invocation) throws Throwable {

// TODO Auto-generated method stub

Object[] args = invocation.getArgs();

MappedStatement ms = (MappedStatement) args[0];

Object parameter = args[1];

RowBounds rowBounds = (RowBounds) args[2];

ResultHandler resultHandler = (ResultHandler) args[3];

Executor executor = (Executor) invocation.getTarget();

CacheKey cacheKey;

BoundSql boundSql;

//由于逻辑关系，只会进入一次

if (args.length == 4) {

//4 个参数时

boundSql = ms.getBoundSql(parameter);

cacheKey = executor.createCacheKey(ms, parameter, rowBounds, boundSql);

} else {

//6 个参数时

cacheKey = (CacheKey) args[4];

boundSql = (BoundSql) args[5];

}

DataScope dataScope = getDataScope(ms);

if (Objects.nonNull(dataScope)) {

String origSql = boundSql.getSql();

log.info("origSql : {}", origSql);

// 组装新的 sql

// todo you weaving business

String newSql = origSql + " limit 1";

// 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 BoundSqlSource(newBoundSql));

for (ParameterMapping mapping : boundSql.getParameterMappings()) {

String prop = mapping.getProperty();

if (boundSql.hasAdditionalParameter(prop)) {

newBoundSql.setAdditionalParameter(prop, boundSql.getAdditionalParameter(prop));

}

}

args[0] = newMs;

if (args.length == 6) {

args[5] = newMs.getBoundSql(parameter);

}

}

LOGGER.info("mybatis intercept sql:{},Mapper 方法是：{}", boundSql.getSql(), ms.getId());

return invocation.proceed();

}

private MappedStatement newMappedStatement(Mapp

【一线大厂Java面试题解析+核心总结学习笔记+最新架构讲解视频+实战项目源码讲义】
浏览器打开：qq.cn.hn/FTf 免费领取

edStatement 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());