我如何使用尝试值以外的值？

Question

我想用Java中的jdbc登录。但是我不能在其他类内部或外部try中使用这些值。

我需要使用walletnumberselected和外部其他字符串来尝试捕获。

我该怎么办？

String sql = "SELECT * FROM  ACCOUNTS where walletnumber = ? ";

prpstmt = conn.prepareStatement(sql);
prpstmt.setInt(1, input_walletnumber);
ResultSet rs2 = prpstmt.executeQuery();


int walletnumberselected  = rs2.getInt("walletnumber"); //Like this
String firstnameselected  = rs2.getString("firstname")  //Like this   
String lastnameselected  = rs2.getString("lastname");   //Like this
String passwordselected  = rs2.getString("password");   //Like this

Answer 1

也许像这样：

String sql = "SELECT * FROM  ACCOUNTS where walletnumber = ? ";
ResultSet rs2 = null;

try {
    prpstmt = conn.prepareStatement(sql);
    prpstmt.setInt(1, input_walletnumber);
    rs2 = prpstmt.executeQuery();
} catch (Exception e) {
    // print error...
}

if (rs2 != null) {
int walletnumberselected  = rs2.getInt("walletnumber"); //Like this
String firstnameselected  = rs2.getString("firstname")  //Like this   
String lastnameselected  = rs2.getString("lastname");   //Like this
String passwordselected  = rs2.getString("password");   //Like this
}