mybatis些拦截器

目录

简单示例

拦截Executor得query方法,打印执行sql时长

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@Intercepts({
        // signature:
        // 1. type 类
        // 2. method 方法
        // 3. 参数
        @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 TestDbInterceptor implements Interceptor {
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[0];
        String sqlId = mappedStatement.getId();
        Object returnValue;

        long start = System.currentTimeMillis();
        returnValue = invocation.proceed();
        long end = System.currentTimeMillis();
        log.info("{} -- {} ", sqlId, end - start);
        return returnValue;
    }
}

全部可被拦截的类

executor

主从库查询的拦截器进行主从切换,aop也可以,但是得拦截方法不如此方法更友好

parameterHandler

statementHandler

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// 分页插件拦截此方法
Statement prepare(Connection connection, Integer transactionTimeout)
    throws SQLException;

void parameterize(Statement statement)
    throws SQLException;

void batch(Statement statement)
    throws SQLException;

int update(Statement statement)
    throws SQLException;

<E> List<E> query(Statement statement, ResultHandler resultHandler)
    throws SQLException;

<E> Cursor<E> queryCursor(Statement statement)
    throws SQLException;

BoundSql getBoundSql();

ParameterHandler getParameterHandler();