爪哇搜索文件

我有2个字符串变量：爪哇搜索文件

“givenAccnt”是从用户

“accntToken”而获得的输入字符串为文本行

的的子串（第一串）

如果givenAccnt 等于 accntToken，我想返回行的与accntToken匹配的文本。

此外，可能存在超过1个匹配的情况。我想将所有匹配保存到一个变量，然后一次返回这些匹配（行）。

以下代码仅在最后一行返回匹配。（如果匹配是在其他线路错过它）

我似乎无法确定它为什么这样表现。

任何帮助，将不胜感激。

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... 
        }

来源

2017-04-25 codEinsteinn

当您使用调试程序遍历代码时，您发现了什么？你为什么每次找到匹配时都创建一个新的'StringBuilder'？只需将匹配追加到'StringBuilder'。这段代码是否编译，'+ fndPwrdsCNTR +“密码（S）找到！”应该是一个语法错误。 –

嗨，Jonny，是的，+ fndPwrdsCNTR +“密码（S）发现！”编译。我看到了这个愚蠢的错误，将再次尝试。谢谢.. – codEinsteinn

您不能在每一行上创建新的StringBuilder。相反，在阅读线路之前创建它。代码：

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... 
        }

来源

2017-04-25 04:12:58

爪哇搜索文件

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