我将如何打印出每行的第一个单词？

Question

我有一个这样的文本文件：

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

我只是想让它打印出每行的第一个单词 不包括数字！

它应该打印为：

Bananas
Pudding    
Soda    
Bread

这是我的代码：

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函数。它根据我们要与字符串拆分的字符返回字符串的数组。在您的情况下，如下所示。

 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+ 你可以使用BufferedReader 的lines() 方法很容易做到这一点：

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

输出：

Bananas
Pudding
Soda
Bread

---

这将在BufferedReader 中的所有行中创建一个Stream，在空白处分割每一行，然后获取第二个标记并打印它

Answer 3

请试试下面的代码-:

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;  
        }
    }
}