2014-09-11 44 views
0

以下是從txt文件中讀取項目並確定事務是否已驗證的代碼。 我遇到了一個問題,當它引發異常格式的異常時,它跳出while循環,然後結束程序。我怎樣才能拋出異常,但之後繼續循環。我確實看過,有人表示每個手柄都有一個試塊,我只是想知道是否有更好的/更清潔的更有效的方法。在JAVA中停止while循環的異常

/* 
* @Author: Louis Krueger 
* @Desc: Homework assignment #2 exception handling 
* @Version: 1.1 
*/ 

package paymentApplication; 

import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.util.ArrayList; 
import java.util.InputMismatchException; 
import java.util.Scanner; 

public class MainHandle { 

     public static ArrayList<String> saPaymentList = new ArrayList<String>(); 

    public static void main(String[] args) { 
     boolean bSkipTrans = false; 
     String sFileName = ""; 
     String sPaymentInfo = ""; 
     String[] saPaymentInfo = null; 
     Scanner keyBoard = new Scanner(System.in); 
     ArrayList<Payment> alPayments = new ArrayList<Payment>(); 

     try{ 
      System.out.println("Enter the file name to be read: "); 
      sFileName = keyBoard.nextLine(); 
      Scanner inputStream = new Scanner(new FileInputStream("details.txt")); 
      System.out.println("Test1"); 
      //loop to Create arraylist of PaymentInfo objects 
      while(inputStream.hasNextLine()) { 
       bSkipTrans = false; 
       Payment Payment = new Payment(); 
       sPaymentInfo = inputStream.nextLine(); 
       saPaymentInfo = sPaymentInfo.split(";"); 
       if(saPaymentInfo.length == 1){ 
        bSkipTrans = true; 
        throw new InvalidTransactionException(); 
       }else{ 
        if(saPaymentInfo.length > 1){ 
         if (isInteger(saPaymentInfo[1]) == true){ 
          Payment.setiTransValue(Integer.parseInt(saPaymentInfo[1])); 
         }else{ 
          //throw exception 
          bSkipTrans = true; 
          throw new InvalidTransactionException("Error#1"); 
         } 
        } 
        if(saPaymentInfo.length > 4){ 
        Payment.setsCreditNumber(saPaymentInfo[4]); 
        } 
        if(saPaymentInfo.length > 3){ 
        Payment.setsDate(saPaymentInfo[3]); 
        } 
        if(saPaymentInfo.length > 2){ 
        Payment.setsName(saPaymentInfo[2]); 
        } 
        if(saPaymentInfo.length > 0){ 
         if(saPaymentInfo[0] != "Cash"|saPaymentInfo[0] != "Credit"){ 
          //throws exception 
          Payment.setsTransType(saPaymentInfo[0]); 
         }else{ 
          bSkipTrans = true; 
          throw new InvalidTransactionException("Error#2"); 
         } 
        } 
       } 
       if(bSkipTrans == true){ 
        //throw exception 
        bSkipTrans = true; 
        throw new InvalidTransactionException("Empty line"); 
       }else{ 
        System.out.println(Payment.toString()); 
        System.out.println("Payment Added"); 
        System.out.println("-------------"); 
        alPayments.add(Payment); 
       } 
      } 
      inputStream.close(); 
     }catch(InputMismatchException e){ 
      System.out.println("Error 1 has occured: " + e.getMessage()); 
     }catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } catch (InvalidTransactionException e) { 
      System.out.println("InvalidTransactionException thrown"); 
     }finally{ 
      System.out.println("Finally statement reached"); 
      keyBoard.close(); 
      System.exit(0); 
     } 
    } 
    public static boolean isInteger(String s) { 
     try { 
      Integer.parseInt(s); 
     } catch(NumberFormatException e) { 
      return false; 
     } 
     // only got here if we didn't return false 
     return true; 
    } 

} 
+0

把while循環中嘗試使捕獲異常後循環仍在延續 – 2014-09-11 01:16:01

+0

不能拋出異常*和*繼續,選擇一個或另一個。如果你想繼續,那麼只需記錄一個錯誤。 – 2014-09-11 01:16:13

+0

異常意味着程序中出現問題,您必須處理它。如果沒關係,只要吃掉它並記錄下問題,否則你最好處理它,然後繼續或傳播給調用者。 – CharlesX 2014-09-11 01:22:08

回答

0

放一個嘗試捕捉while循環中:

/* 
* @Author: Louis Krueger 
* @Desc: Homework assignment #2 exception handling 
* @Version: 1.1 
*/ 

package paymentApplication; 

import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.util.ArrayList; 
import java.util.InputMismatchException; 
import java.util.Scanner; 

public class MainHandle { 

     public static ArrayList<String> saPaymentList = new ArrayList<String>(); 

    public static void main(String[] args) { 
     boolean bSkipTrans = false; 
     String sFileName = ""; 
     String sPaymentInfo = ""; 
     String[] saPaymentInfo = null; 
     Scanner keyBoard = new Scanner(System.in); 
     ArrayList<Payment> alPayments = new ArrayList<Payment>(); 

     try{ 
      System.out.println("Enter the file name to be read: "); 
      sFileName = keyBoard.nextLine(); 
      Scanner inputStream = new Scanner(new FileInputStream("details.txt")); 
      System.out.println("Test1"); 
      //loop to Create arraylist of PaymentInfo objects 
      while(inputStream.hasNextLine()) { 
       try{ 
        bSkipTrans = false; 
        Payment Payment = new Payment(); 
        sPaymentInfo = inputStream.nextLine(); 
        saPaymentInfo = sPaymentInfo.split(";"); 
        if(saPaymentInfo.length == 1){ 
         bSkipTrans = true; 
         throw new InvalidTransactionException(); 
        }else{ 
         if(saPaymentInfo.length > 1){ 
          if (isInteger(saPaymentInfo[1]) == true){ 
           Payment.setiTransValue(Integer.parseInt(saPaymentInfo[1])); 
          }else{ 
           //throw exception 
           bSkipTrans = true; 
           throw new InvalidTransactionException("Error#1"); 
          } 
         } 
         if(saPaymentInfo.length > 4){ 
         Payment.setsCreditNumber(saPaymentInfo[4]); 
         } 
         if(saPaymentInfo.length > 3){ 
         Payment.setsDate(saPaymentInfo[3]); 
         } 
         if(saPaymentInfo.length > 2){ 
         Payment.setsName(saPaymentInfo[2]); 
         } 
         if(saPaymentInfo.length > 0){ 
          if(saPaymentInfo[0] != "Cash"|saPaymentInfo[0] != "Credit"){ 
           //throws exception 
           Payment.setsTransType(saPaymentInfo[0]); 
          }else{ 
           bSkipTrans = true; 
           throw new InvalidTransactionException("Error#2"); 
          } 
         } 
        } 
        if(bSkipTrans == true){ 
         //throw exception 
         bSkipTrans = true; 
         throw new InvalidTransactionException("Empty line"); 
        }else{ 
         System.out.println(Payment.toString()); 
         System.out.println("Payment Added"); 
         System.out.println("-------------"); 
         alPayments.add(Payment); 
        } 

       } catch (InvalidTransactionException e) { 
        System.out.println("InvalidTransactionException thrown"); 
       } 
      } 

      inputStream.close(); 
     }catch(InputMismatchException e){ 
      System.out.println("Error 1 has occured: " + e.getMessage()); 
     }catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     finally{ 
      System.out.println("Finally statement reached"); 
      keyBoard.close(); 
      System.exit(0); 
     } 
    } 
    public static boolean isInteger(String s) { 
     try { 
      Integer.parseInt(s); 
     } catch(NumberFormatException e) { 
      return false; 
     } 
     // only got here if we didn't return false 
     return true; 
    } 

}