Question

我要做的是从最终用户那里获取输入并将其写入名为 dictionary.txt 的文件。然后我试图检查最终用户输入的单词是否已经在dictionary.txt文件中，因为我不想要重复。如果单词不在字典中，那么它将存储在dictionary.txt中。我遇到的问题是compilation error告诉我Project3.java:81: not a statement FileWriter aDictionary = new FileWriter("dictionary.txt", true);。

public static void addNewWord()throws IOException
{
    String newWord = "";
    newWord = JOptionPane.showInputDialog(null, "Enter the word you want to add to your dictionary.");
    String aLineFromFile = "";
    String filename = "dictionary.txt";
    ArrayList<String> dictionary = new ArrayList<String>();
    File resultsFile = new File(filename);
    Scanner inFile = new Scanner(resultsFile);

    while(inFile.hasNext())
         aLineFromFile = inFile.nextLine();
         if (aLineFromFile.startsWith(newWord))
         {
            dictionary.add(aLineFromFile);
            JOptionPane.showMessageDialog(null, "Word already is dictionary");
            addNewWord();
                 }

 else
    FileWriter aDictionary = new FileWriter("dictionary.txt", true);
    PrintWriter out = new PrintWriter(aDictionary);
    out.println(newWord);
    out.close();
    aDictionary.close();

  return;
}

我已导入java.io.*; javax.swing.*; java.awt.Dimension; java.util.*; 如果有人可以告诉我为什么我会收到此错误并告诉我如何修复它，我将非常感激。

Answer 1

不要忘记缩进，这有助于查看缺少的大括号和范围。

这应该更好：

public static void addNewWord() throws IOException {
    String newWord = JOptionPane.showInputDialog(null, "Enter the word you want to add to your dictionary.");
    String filename = "dictionary.txt";
    File resultsFile = new File(filename);
    Scanner inFile = new Scanner(resultsFile);
    List<String> dictionary = new ArrayList<String>();
    while (inFile.hasNext()) {
        String aLineFromFile = inFile.nextLine();
        if (aLineFromFile.startsWith(newWord)) {
            dictionary.add(aLineFromFile);
            JOptionPane.showMessageDialog(null, "Word already is dictionary");
            addNewWord();
        } else {
            FileWriter aDictionary = new FileWriter("dictionary.txt", true);
            PrintWriter out = new PrintWriter(aDictionary);
            out.println(newWord);
            out.close();
            aDictionary.close();
        }
    }
}

Answer 2

在此{}块

中放置其他代码像这样

else{
         FileWriter aDictionary = new FileWriter("dictionary.txt", true);
         PrintWriter out = new PrintWriter(aDictionary);
         out.println(newWord);
         out.close();
         aDictionary.close();
      }

Answer 3

使用以下修改后的代码。在while循环后你错过了大括号，否则阻止

public static void addNewWord() throws IOException {
    String newWord = "";
    newWord = JOptionPane.showInputDialog(null, "Enter the word you want to add to your dictionary.");
    String aLineFromFile = "";
    String filename = "dictionary.txt";
    ArrayList<String> dictionary = new ArrayList<String>();
    File resultsFile = new File(filename);
    Scanner inFile = new Scanner(resultsFile);

    while (inFile.hasNext()) {
        aLineFromFile = inFile.nextLine();
        if (aLineFromFile.startsWith(newWord)) {
            dictionary.add(aLineFromFile);
            JOptionPane.showMessageDialog(null, "Word already is dictionary");
            addNewWord();
        } else {
            FileWriter aDictionary = new FileWriter("dictionary.txt", true);
            PrintWriter out = new PrintWriter(aDictionary);
            out.println(newWord);
            out.close();
            aDictionary.close();
        }
    }
}

Answer 4

这是你的代码，但这只是问题的开始：

    public static void addNewWord() throws IOException {
        String newWord;
        newWord = JOptionPane.showInputDialog(null, "Enter the word you want to add to your dictionary.");
        String aLineFromFile = "";
        String filename = "dictionary.txt";
        ArrayList<String> dictionary = new ArrayList<String>();
        File resultsFile = new File(filename);
        Scanner inFile = new Scanner(resultsFile);
        while (inFile.hasNext()) {
            aLineFromFile = inFile.nextLine();
            if (aLineFromFile.startsWith(newWord)) {
                dictionary.add(aLineFromFile);
                JOptionPane.showMessageDialog(null, "Word already is dictionary");
                addNewWord();
            } else {
                FileWriter aDictionary = new FileWriter("dictionary.txt", true);
                PrintWriter out = new PrintWriter(aDictionary);
                out.println(newWord);
                out.close();
                aDictionary.close();
            }
        }
    }

我认为这是错误的构思。使用UI / Swing类混合这样的功能是没有充分理由的。将两者分开，否则你将无法在没有Swing UI的情况下使用此方法。它被称为分层或关注点分离。

Answer 5

更好的格式化：

public static void addNewWord()throws IOException {

    String newWord = "";
    newWord = JOptionPane.showInputDialog(null, "Enter the word you want to add to your dictionary.");
    String aLineFromFile = "";
    String filename = "dictionary.txt";
    ArrayList<String> dictionary = new ArrayList<String>();
    File resultsFile = new File(filename);
    Scanner inFile = new Scanner(resultsFile);

    while (inFile.hasNext()) {
        aLineFromFile = inFile.nextLine();
        if (aLineFromFile.startsWith(newWord)) {
            dictionary.add(aLineFromFile);
            JOptionPane.showMessageDialog(null, "Word already is dictionary");
            addNewWord();
        }

        else {
            FileWriter aDictionary = new FileWriter("dictionary.txt", true);
            PrintWriter out = new PrintWriter(aDictionary);
            out.println(newWord);
            out.close();
            aDictionary.close();
        }
    }

    return;
}

为代码块保留一个4个字符的缩进，即使你必须单独使用空格和删除键（与编辑器一起为你完成）。从长远来看，它可以节省您的时间。

小错误我不知道如何修复，“不是声明”

5 个答案: