是否需要关闭本地主机中的 jdbc 连接

Question

I use static methods in a java project that i build, to make queries to a localhost mysql db.

Something like that:

public static void sqlQuery() {
    Connection conn = null;
    PreparedStatement stmt = null;
    ResultSet rs = null;
    try {
        conn = DriverManager.getConnection(localhost,root,password);
        stmt = conn.prepareStatement(Some SQL);
        rs = stmt.executeQuery();
    } catch(Exception e) {
        // Error Handling
    } finally {
        try { if (rs != null) rs.close(); } catch (Exception e) {};
        try { if (stmt != null) stmt.close(); } catch (Exception e) {};
        try { if (conn != null) conn.close(); } catch (Exception e) {};
    }
}

My Question is if i can keep the conn variable without close it and reuse it again for another query.

No other app use this db and i can do that i want with only 1 connection..

PS Sorry for my bad english..

Answer 1

You can reuse a connection in the same context. Once you have changed your context, you should close the former connection and reopen another connection.

Answer 2

连接不是线程安全的，因此仅使用一个连接会带来危险。您应该使用连接池，为每个逻辑活动提供一个新的逻辑连接。

Answer 3

You should always close resources like JDBC connection. If you don't close them, it creates a resource leak and it can slow down your program.

Answer 4

It is always advisable to close the connection, since its not a thread safe. It is also not advisable to keep the connection object as the singleton.