如何打印每行的第一個單詞？

Question

我有一個文本文件，內容如下：

1. Bananas that are not green
2. Pudding that is not vanilla
3. Soda that is not Pepsi
4. Bread that is not stale

我只希望它打印出每行的第一個單詞（ 不包括數字）！

它應打印為：

Bananas
Pudding    
Soda    
Bread

這是我的代碼：

public static void main(String[] args) {
    BufferedReader reader = null;
    ArrayList <String> myFileLines = new ArrayList <String>();

    try {
        String sCurrentLine;
        reader = new BufferedReader(new 
                FileReader("/Users/FakeUsername/Desktop/GroceryList.txt"));
        while ((sCurrentLine = reader.readLine()) != null) {
            System.out.println(sCurrentLine);               
        }
    } catch (IOException e) {
        e.printStackTrace();
        System.out.print(e.getMessage());
    } finally {
        try {
            if (reader != null)reader.close();
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
            ex.printStackTrace();
        }
    }
}

Answer 1

使用String的split函數。 它根據要與字符串分割的字符返回String的數組。 您的情況如下。

 String sCurrentLine = new String();
 reader = new BufferedReader(new 
                FileReader("/Users/FakeUsername/Desktop/GroceryList.txt"));
 while ((sCurrentLine = reader.readLine() != null) {
    String words[] = sCurrentLine.split(" ");
    System.out.println(words[0]+" "+words[1]);
 } 

Answer 2

Java 8+，您可以使用BufferedReader的lines()方法很容易地做到這一點：

String filename = "Your filename";
reader = new BufferedReader(new FileReader(fileName));
reader.lines()
      .map(line -> line.split("\\s+")[1])
      .forEach(System.out::println);

輸出：

Bananas
Pudding
Soda
Bread

---

這將在BufferedReader創建所有行的Stream ，在BufferedReader分割每一行，然后獲取第二個標記並打印它

Answer 3

請嘗試以下代碼-：

outerWhileLoop: 
while ((sCurrentLine = reader.readLine()) != null) {
     //System.out.println(sCurrentLine);
     StringTokenizer st = new StringTokenizer(sCurrentLine," .");
     int cnt = 0;
     while (st.hasMoreTokens()){
        String temp = st.nextToken();
        cnt++;
        if (cnt == 2){
           System.out.println(temp);
           continue outerWhileLoop;  
        }
    }
}