java - java中字符串的使用

Question

考虑将下面代码中的 URL 分配给一个字符串，例如

String link = "http://www.topix.com/rss/city/ellensburg-wa";

我应该如何使用下面代码中的字符串而不是 URL 本身。

注意:我是java初学者

 stmt.executeQuery("select url from urls where url='http://www.topix.com/rss/city/ellensburg-wa'");

 stmtR.executeUpdate("insert into urls values(21211,'http://www.topix.com/rss/city/ellensburg-wa','source',1,0)"

Answer 1

如果你想创建一个好的查询，请使用 prepared statement

PreparedStatement insertUrlStatement = con.prepareStatement("INSERT INTO urls VALUES(?, ?, ?, ?)");
//Replace the **first** "?" by an "id" variable content (containing an **int**)
insertUrlStatement.setInt(1, id);
//Replace the **second** "?" by the "url" variable content (containing a **String**)
insertUrlStatement.setString(2, url);
//Two other setXxx();
insertUrlStatement.executeUpdate()