Java-从同一个 Statement 对象创建多个 ResultSets-它会有什么影响吗？

Question

我从同一个Statement 对象生成了2 个ResultSet。

代码示例如下:

Connection con            = null;
Statement  stmt           = null;
ResultSet rs = null;

con = DBAccess.getConnection();
stmt = con.createStatement();

rs = stmt.executeQuery(Query1);
// operate on the resultset

rs = stmt.executeQuery(Query2);   // Is it legal and do not have side-effects?
// operate on the resultset

// close everythings (Resultset, Statement, Connection)

我检查过它运行良好。我怀疑它会有任何副作用吗？

Answer 1

来自javadoc :

By default, only one ResultSet object per Statement object can be open at the same time. Therefore, if the reading of one ResultSet object is interleaved with the reading of another, each must have been generated by different Statement objects. All execution methods in the Statement interface implicitly close a statment's current ResultSet object if an open one exists.

所以是的，你可以安全地做到这一点。在执行第二个查询后，您就无法使用第一个结果集。