java请求action超时，怎么停止mysql继续查询数据库？

Question

由于查询的sql过于复杂，导致前端请求action超时，页面已经停止了，但此时从数据库show processlist看，那条查询语句还在继续执行，请问下，怎么在前端超时的同时，那条查询sql也能自动被kill掉呢？不然数据库服务器的cpu一直被占着。。

Answer 1

贴个Statement.cancel()的文档：

/**
     Cancels this <code>Statement</code> object if both the DBMS and
     driver support aborting an SQL statement.
     This method can be used by one thread to cancel a statement that
     is being executed by another thread.
    
     @exception SQLException if a database access error occurs or
     this method is called on a closed <code>Statement</code>
     @exception SQLFeatureNotSupportedException if the JDBC driver does not support
     this method
   */
     
    void cancel() throws SQLException;
    

根据javadoc的描述，如果DBMS和驱动都支持的话是可以使用这个api结束
可以先设置超时时间：

    void setQueryTimeout(int seconds) throws SQLException;
    

捕获这个异常然后cancel()

Answer 2

mysql超时设置吧