爪哇搜索文件

我有2個字符串變量：爪哇搜索文件

「givenAccnt」是從用戶

「accntToken」而獲得的輸入字符串爲文本行

的的子串（第一串）

如果givenAccnt 等於 accntToken，我想返回行的與accntToken匹配的文本。

此外，可能存在超過1個匹配的情況。我想將所有匹配保存到一個變量，然後一次返回這些匹配（行）。

以下代碼僅在最後一行返回匹配。（如果匹配是在其他線路錯過它）

我似乎無法確定它爲什麼這樣表現。

任何幫助，將不勝感激。

givenAccnt = searchTextField.getText();//else, user is using search field to get given account 
try 
    { 
     scanner = new Scanner(file);  //initialize scanner on file 
     while(scanner.hasNextLine())  //while lines are being scanned 
     { 
     getLine = scanner.nextLine();   //gets a line 
     int i = getLine.indexOf(' ');   //get first string-aka-accnToken 
     accntToken = getLine.substring(0, i);  
     } 
     if(givenAccnt.equals(accntToken)) //if match 
     { 
      collectedLines = new StringBuilder().append(getLine).toString(); 
      psswrdLabels = new JLabel(collectedLines, JLabel.LEFT); 
      psswrdLabels.setAlignmentX(0); 
      psswrdLabels.setAlignmentY(0); 
      fndPwrdsCNTR += 1;  //counter for number of passwords found 
      JOptionPane.showMessageDialog(null, psswrdLabels ,+fndPwrdsCNTR+" PASSWORD(S) FOUND!", JOptionPane.INFORMATION_MESSAGE); //shows window with matched passwords (as JLabels) 
          searchTextField.setText(""); //clears search field, if it was used 
     }else 
      //..nothing found 
    }catch (FileNotFoundException ex) { 
     //..problem processing file... 
        }

來源

2017-04-25 codEinsteinn

當您使用調試程序遍歷代碼時，您發現了什麼？你爲什麼每次找到匹配時都創建一個新的'StringBuilder'？只需將匹配追加到'StringBuilder'。這段代碼是否編譯，'+ fndPwrdsCNTR +「密碼（S）找到！」應該是一個語法錯誤。 –

嗨，Jonny，是的，+ fndPwrdsCNTR +「密碼（S）發現！」編譯。我看到了這個愚蠢的錯誤，將再次嘗試。謝謝.. – codEinsteinn

您不能在每一行上創建新的StringBuilder。相反，在閱讀線路之前創建它。代碼：

givenAccnt = searchTextField.getText();//else, user is using search field to get given account 
try 
    { 
builder=new StringBuilder();//initialize builder to store matched lines 
     scanner = new Scanner(file);  //initialize scanner on file 
     while(scanner.hasNextLine())  //while lines are being scanned 
     { 
     getLine = scanner.nextLine();   //gets a line 
     int i = getLine.indexOf(' ');   //get first string-aka-accnToken 
     accntToken = getLine.substring(0, i);  
     } 
     if(givenAccnt.equals(accntToken)) //if match 
     { 
      collectedLines = builder.append(getLine).toString(); 
      psswrdLabels = new JLabel(collectedLines, JLabel.LEFT); 
      psswrdLabels.setAlignmentX(0); 
      psswrdLabels.setAlignmentY(0); 
      fndPwrdsCNTR += 1;  //counter for number of passwords found 
      JOptionPane.showMessageDialog(null, psswrdLabels ,+fndPwrdsCNTR+" PASSWORD(S) FOUND!", JOptionPane.INFORMATION_MESSAGE); //shows window with matched passwords (as JLabels) 
          searchTextField.setText(""); //clears search field, if it was used 
     }else 
      //..nothing found 
    }catch (FileNotFoundException ex) { 
     //..problem processing file... 
        }

來源

2017-04-25 04:12:58

爪哇搜索文件

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