java - 从文件中读取字符串，但删除了一行空格后的任何文本？

Question

我有一个包含以下短语的大文本文件：

citybred JJ 
Brestowe NNP 
STARS NNP NNS
negative JJ NN
investors NNS NNPS
mountain NN 

我的目标是保留每行的第一个单词，不带空格，并将它们设为小写。前任：

citybred 
brestowe
stars
negative
investors
mountain

如果评估了上述文本，将返回。

有什么帮助吗？

当前代码：

public class FileLinkList
{
    public static void main(String args[])throws IOException{
        String content = new String();
        File file = new File("abc.txt");
        LinkedList<String> list = new LinkedList<String>();

        try {
            Scanner sc = new Scanner(new FileInputStream(file));
            while (sc.hasNextLine()){
                content = sc.nextLine();
                list.add(content);
            }
            sc.close();
        } catch(FileNotFoundException fnf){
            fnf.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("\nProgram terminated Safely...");
        }

        Collections.reverse(list);
        Iterator i = list.iterator();
        while (i.hasNext()) {
            System.out.print("Node " + (count++) + " : ");
            System.out.println(i.next());
        }
    }
}

Answer 1

如果您的令牌及其 POS 标签由空格分隔：

public class FileLinkList{

    public static void main(String[] args) {

        BufferedReader br = null;
            LinkedList<String> list = new LinkedList<String>();
            String word;
        try {
            String sCurrentLine;
            br = new BufferedReader(new FileReader("LEXICON.txt"));
            while ((sCurrentLine = br.readLine()) != null) {
                System.out.println(sCurrentLine);
                            word = sCurrentLine.trim().split(" ")[0];
                            list.add(word.toLowerCase());
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)
                                br.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

Answer 2

添加以下内容：

content = sc.nextLine();
string[] tokens = content.split(new char[] {' '}, StringSplitOptions.RemovEemptyEntries);
// You can add some validations here...
string word = tokens[0].ToLowerCase();

Answer 3

试试这个 ：

public class FileLinkList {
    public static void main(String args[])throws IOException{
        String content = new String();
        int count=1;
        File file = new File("abc.txt");
        LinkedList<String> list = new LinkedList<String>();

        try {
            Scanner sc = new Scanner(new FileInputStream(file));
            while (sc.hasNextLine()){
                content = sc.nextLine();
                if (content != null && content.length() > 0)) {
                    list.add(content.trim().split(" ")[0].toLowerCase());
                }
            }
            sc.close();
        } catch(FileNotFoundException fnf){
            fnf.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("\nProgram terminated Safely...");
        }

        for (String listItem : list) {
            System.out.println(listItem);
        }
    }
}

Answer 4

使用 Apache Commons IO，将文件读入字符串列表要简单得多。

import org.apache.commons.io.FileUtils;

List<String> lines = FileUtils.readLines(new File("abc.txt"));
List<String firstWords = new ArrayList<>();
for (String line : lines) {
  String firstWord = line.split(" ")[0].toLowerCase();
  firstWords.add(firstWord);
}