Question

我有一个文本文件，内容如下：

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个单词 不包含数字！

它应打印为：

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。它根据要与字符串分割的字符返回String的数组。您的情况如下。

 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{{3}}方法很容易地做到这一点：

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

Answer 3

请尝试以下代码-：

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;  
        }
    }
}

如何打印每行的第一个单词？

3 个答案: