如何检查用户输入路径是否正确？

Question

我需要证明用户输入路径。
因为用户不给文件夹路径而是文件路径。计划“倒下”。
我知道这是一个错误，但如何确保用户路径正确。

代码：

class PathAndWord { 
    final String path; 
    final String whatFind; 

    PathAndWord(String path, String whatFind) { 
     this.path = path; 
     this.whatFind = whatFind; 
    } 

    boolean isProperlyInitialized() { 
     return path != null && whatFind != null; 
    } 
} 

public void askUserPathAndWord() { 
    try { 
     tryToAskUserPathAndWord(); 
    } catch (IOException | RuntimeException e) { 
     System.out.println("Wrong input!"); 
     e.printStackTrace(); 
    } catch (InterruptedException e) { 
     System.out.println("Interrupted."); 
     e.printStackTrace(); 
    } 
} 

private void tryToAskUserPathAndWord() throws IOException, InterruptedException { 
    PathAndWord pathAndWord = readPathAndWord(); 

    if (pathAndWord.isProperlyInitialized()) { 
     performScan(pathAndWord, "GameOver.tmp"); 
     System.out.println("Thank you!"); 
    } else { 
     System.out.println("You did not enter anything"); 
    } 
} 

private PathAndWord readPathAndWord() throws IOException { 
    System.out.println("Please, enter a Path and Word (which you want to find):"); 

    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in)); 

    String path = readPath(bufferedReader); 
    String whatFind = readWord(bufferedReader); 
    return new PathAndWord(path, whatFind); 
} 

private String readPath(BufferedReader bufferedReader) throws IOException { 
    System.out.println("Please enter a Path:"); 
    return bufferedReader.readLine(); 
} 

private String readWord(BufferedReader bufferedReader) throws IOException { 
    System.out.println("Please enter a Word:"); 
    return bufferedReader.readLine(); 
} 

private void performScan(PathAndWord pathAndWord, String endOfWorkFileName) throws InterruptedException { 
    BlockingQueue<File> queue = new LinkedBlockingQueue<File>(); 

    File endOfWorkFile = new File(endOfWorkFileName); 
    CountDownLatch latch = new CountDownLatch(2); 

    FolderScan folderScan = new FolderScan(pathAndWord.path, queue, latch, 
      endOfWorkFile); 
    FileScan fileScan = new FileScan(pathAndWord.whatFind, queue, latch, 
      endOfWorkFile); 

    Executor executor = Executors.newCachedThreadPool(); 
    executor.execute(folderScan); 
    executor.execute(fileScan); 

    latch.await(); 
} 

Qustions：

• 如何检查，如果用户输入path是正确的？
• 如果路径不正确 要显示消息path is wrong! Try again。
• 能够检查词 - whatFind是否正确。
• 以前需要做点什么吗？

Answer 1

private String readPath(BufferedReader bufferedReader) throws IOException { 
    boolean ok = false; 
    do { 
     System.out.println("Please enter a Path:"); 
     File f = new File(bufferedReader.readLine()); 
     if(f.exists() && f.isDirectory()) 
      ok = true; 
     else 
      System.err.println("Doesn't exist or is not a folder."); 
    } while(!ok); 
    return f.getAbsolutePath(); 
} 

编辑：此方法执行任务的“读取用户，这存在且是一个目录的路径”。如果用户键入无效路径（不存在或文件），该方法可以识别这一点，警告用户并再次询问他们......并一次又一次 - 直到他们正确回答。

如果可以的话，在本地检查数据是一种很好的习惯。稍后调用方法时，您可以确定它会返回，您期望的是什么。