如何将数据从Access数据库加载到int数组中？

Question

我正在寻找一种方法来验证用户输入的数字是否与存储在数据库中的数据一致。例如。如果用户输入'5132'，它会将来自特定列的所有数据加载到数组中，然后循环该数据并将输入与它进行比较以寻找匹配。

简单说明：如何将数据从数据库（resultset）解析到int数组中？

什么我试着让在

String s = JOptionPane.showInputDialog(...); 
int intS = Integer.parseInt(s); 
boolean correct = false; 

Get database info 
count++; //for every data entry 

int TagNumber [] = new int [count]; 

for (int i=0;i<count;i++) { 
if (intS == TagNumber[i]) { 
    correct =true; 
    break; 
} 
} 

Answer 1

如果你真的想从数据库加载值和用户检查特定的值，那么你可以使用二进制搜索一个简单的例子，否则你也可以使用SQL查询。

下面是一个实现（二进制搜索）来查找数组中的值。

public class BinarySearch { 

    public static void main(String[] a) { 
     int[] numArray = {5,6,10,11,19,18,30,25,88,44,55,1,3}; 
     Arrays.sort(numArray); 
     // performing a binary search - here 100 is the element that you want 
      // to search in your array 
     System.out.println(searchElement(numArray, 100)); 
    } 

    private static int searchElement(int[] sortedArray, int element) { 

     int first = 0; 
     int upto = sortedArray.length; 

     while (first < upto) { 
      int mid = (first + upto)/2; // Compute mid point. 
      if (element < sortedArray[mid]) { 
       upto = mid;  // repeat search in bottom half. 
      } else if (element > sortedArray[mid]) { 
       first = mid + 1; // Repeat search in top half. 
      } else { 
       return sortedArray[mid];  // Found it. You can return the position or the element 
      } 
     } 
     return -1; // The element is not in the array 
    } 
} 

的数据库功能

public class RetrieveValues { 
    public static void main(String args[]) throws SQLException { 
     Connection conn = null; 
     Statement select = null; 
     try { 
      Class.forName("com.somejdbcvendor.TheirJdbcDriver"); 
      conn = DriverManager.getConnection(
          "jdbc:somejdbcvendor:other data needed by some jdbc vendor", 
          "myLogin", "myPassword"); 
      select = conn.createStatement(); 
      ResultSet result = select 
        .executeQuery("SELECT Element FROM TestTable"); 

      List<Integer> elementList = new ArrayList<Integer>(); 
      while (result.next()) { // process results one row at a time 
       elementList.add(result.getInt(1)); 
      } 
      // convert to int array 

      convertIntegers(elementList); 

     } catch (SQLException e) { 
      e.printStackTrace(); 
     } catch (ClassNotFoundException e) { 
      e.printStackTrace(); 
     } finally { 
      select.close(); 
      conn.close(); 
     } 
    } 

    public static int[] convertIntegers(List<Integer> elemIntegers) 
    { 
     int[] elements = new int[elemIntegers.size()]; 
     for (int i=0; i < elements.length; i++) 
     { 
      elements[i] = elemIntegers.get(i).intValue(); 
     } 
     return elements; 
    } 
}