读取由制表符分隔的文件并将单词放入 ArrayList

2022-01-09 00:00:00 file-io tabs java

我正在做一个自学练习，以帮助我更多地了解 Java，但我被这个问题困住了.我有以下 txt 文件:

I am doing a self learning exercise to help me understand more about Java, but I am stuck at this question. I have the following txt file:

Name  Hobby 
Susy  eat fish 
Anna  gardening
Billy bowling with friends

注意:姓名和爱好用制表符隔开

阅读所有行并将其放入 arraylist(name,hobby) 的最佳方法是什么.棘手的部分是

What is the best way to read all the line and put it in arraylist(name,hobby). The tricky part is that

eat fish or bowling with friends

有空格，它必须放在一个数组下，显然我无法对其进行硬编码.这是我当前的代码:

has white spaces and it must be put under one array and obviously I cannot hardcode it. Here is my current code:

 public void openFile(){
            try{
                FileInputStream fstream = new    FileInputStream("textfile.txt");
          // use DataInputStream to read binary NOT text
          BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
          ArrayList<String> names = new ArrayList<String>();
          ArrayList<String> hobbies = new ArrayList<String>();
          String lineJustFetched;
          while ((lineJustFetched = br.readLine()) != null)   {
          String[] tokens = lineJustFetched.split(" 	");

我遇到了一个错误:

java.lang.StringIndexOutOfBoundsException:字符串索引超出范围:-1

java.lang.StringIndexOutOfBoundsException: String index out of range: -1

我怀疑计算索引在选项卡上不是很有用.有什么想法吗?

I suspect counting the index is not very useful on a tab. Any idea?

推荐答案

好的，你需要按照下图的方法进行:

Alright, you need to do the recipe shown below:

  1. 创建一个BufferedReader
  2. 创建一个ArrayList
  3. 开始将数据读取到名为 lineJustFetched 的 String 变量中.
  4. 调用lineJustFetched.split(" ");
    5. 分割String
  5. 迭代生成的 String[].检查你要进入ArrayList的token是否不是""
  6. 如果没有，则将单词添加到 ArrayList
  1. Create a BufferedReader
  2. Create an ArrayList<String>
  3. Start reading data into a String variable named lineJustFetched.
  4. Split the String by calling lineJustFetched.split(" ");
  5. Iterate over the String[] produced. Check if the token you want to enter into the ArrayList is not ""
  6. If not, add the word to the ArrayList

您指定需要根据 值进行拆分，这样空格就不会成为问题.

You specify that you need to split based on values so white spaces won't be an issue.

SSCCE 

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;

public class WordsInArray {
    public static void main(String[] args) {
        try{
            BufferedReader buf = new BufferedReader(new FileReader("/home/little/Downloads/test"));
            ArrayList<String> words = new ArrayList<>();
            String lineJustFetched = null;
            String[] wordsArray;

            while(true){
                lineJustFetched = buf.readLine();
                if(lineJustFetched == null){  
                    break; 
                }else{
                    wordsArray = lineJustFetched.split("	");
                    for(String each : wordsArray){
                        if(!"".equals(each)){
                            words.add(each);
                        }
                    }
                }
            }

            for(String each : words){
                System.out.println(each);
            }

            buf.close();

        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

输出 

John
likes to play tennis
Sherlock
likes to solve crime

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