Java：扫描仪停在新线上 [英] Java: Scanner stopping at new line

问题描述

我正在尝试扫描文本文件并将它们添加到地图中，地图和一切正常。 但是，当涉及到文本文件中的输入或空白行时，扫描程序似乎停止了。这是我的问题

I am trying to scan through text files and add them to a map, the map and everything is working. However, the scanner seems to be stopping when it comes to a 'enter' in the text file, or a blank line. This is my problem

这是我的扫描仪/映射器代码块

here is my block of code for the scanner/mapper

class OneButtonListener implements ActionListener
{
    @Override
    public void actionPerformed(ActionEvent evt)
    {
        final JFileChooser oneFC = new JFileChooser();
        oneFC.showOpenDialog(AnalysisFrame.this);
        String newLine = null;
        oneFC.getName(null);
        int returnVal = 0;
        File fileOne = oneFC.getSelectedFile();

        Scanner input = null;        
        try {
            input = new Scanner(fileOne);
        } 
        catch (FileNotFoundException ex) {
            Logger.getLogger(AnalysisFrame.class.getName()).log(Level.SEVERE, null,
                            ex);
        }                       
        inputText = input.nextLine(); 
        String[] words = inputText.split("[ \n\t\r,.;:!?(){}]");

        for(int i = 0; i < words.length; i++){
            key = words[i].toLowerCase(); 

            if (words[i].length() > 1){
                if (mapOne.get(key) == null){
                    mapOne.put(key, 1);
                }
                else {
                    value1 = mapOne.get(key).intValue();
                    value1++;
                    apOne.put(key, value1);
                }
            } 
         }
     }
}

感谢您的帮助！

推荐答案

您应该在循环内扫描，直到它到达文件的末尾，示例：

You should scan inside a loop until it reaches the end of the file, for example:

StringBuilder builder = new StringBuilder();
while(input.hasNextLine()){
    builder.append(input.nextLine());
    builder.append(" "); // might not be necessary
}
String inputText = builder.toString();

使用 split 的替代方法可能是使用分隔符，使用扫描程序并使用 hasNext（）和 next（）而不是 hasNextLine（）和 nextLine（）。尝试一下，看看它是否有效。

An alternative to using split could be to use a Delimiter with the Scanner and use hasNext() and next() instead of hasNextLine() and nextLine(). Try it out, see if it works.

例如：

scanner.useDelimiter("[ \n\t\r,.;:!?(){}]");
ArrayList<String> tokens = new ArrayList<String>();
while(scanner.hasNext()){
    tokens.add(scanner.next());
}

String[] words = tokens.toArray(new String[0]); // optional

另外在旁注中，没有必要创建 JFileChooser 每次：

Also on a side note, it's not necessary to create the JFileChooser everytime:

class OneButtonListener implements ActionListener
{
    private final JFileChooser oneFC = new JFileChooser();

    @Override
    public void actionPerformed(ActionEvent evt)
    {

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