java - 将文本字符串读入二维数组

Question

需要将一组文本字符串文件读入二维数组。文本字符串格式如下所示，每行以不同长度的“\n”结尾

    "dog", "runs", "fast"
    "birds", "flies", "high"
    "baby", "cries", "often", "in the evening"
    "He", "works"
    ....

想要获得下面的二维数组输出:

  { {"dog", "runs", "fast"}, {"birds", "flies", "high"}, 
    {"baby", "cries", "often", "in the evening"}, {"He", "works"}, 
     ...
  }

考虑使用 StringBuilder 从文件中读取每一行并将其附加到 2D Object [][] 数组(但使用 String [][] 代替)。以下代码是我最初的尝试 - 不太漂亮，但也不起作用。

                   import java.io.*;
                   import java.util.*;

                  public class My2DArrayTest
                          {
                  public static void main(String args[])
                           {

                String[][] myString = new String[4][3];

                        try
                               {
                        FileReader file = new FileReader("MyTestFile.txt");
                        BufferedReader reader = new BufferedReader (file);
                         String strLine;
                          String EXAMPLE_TEST;  
                           for (int row = 0;  row < 4;  row++) {
                      for (int column = 0;  column < 3;  column++) {
                            while ((strLine = reader.readLine()) != null{

                        if (strLine.length() > 0) {
                      EXAMPLE_TEST = strLine;
                           System.out.println ("This is EXAMPLE_TEST: " +   
                                     EXAMPLE_TEST);


               myString[row][column]=EXAMPLE_TEST;
               System.out.println("Current row: " + row);
               System.out.println("Current column: " + column);
               System.out.println("This is myString Array:" + 
                                    myString[row][column] + " ");
                }
                  }  
                                     }
                                                              }
                               file.close();

                   }   catch( IOException ioException ) {}
                                 }
                                      }

Answer 1

首先，您必须决定如何处理您不知道开始时的行数这一事实。你可以:

1. 首先计算行数以创建所需大小的结果数组，然后再次读取文件并用数据填充该数组。
2. 将您的行存储在 List 中。

(我会选择2)其次，您希望在字符串中允许使用哪些字符？例如 " 或 \n (换行符)会让事情变得更复杂，因为你必须转义它们，但我们假设这些字符将被禁止(还有 ​​,，这样我们就可以更容易地拆分)

Scanner in = new Scanner(new File("strings.test"));
List<String[]> lines = new ArrayList<>();
while(in.hasNextLine()) {
    String line = in.nextLine().trim();
    String[] splitted = line.split(", ");
    for(int i = 0; i<splitted.length; i++) {
        //get rid of additional " at start and end
        splitted[i] = splitted[i].substring(1, splitted[i].length()-1);
    }
    lines.add(splitted);
}

//pretty much done, now convert List<String[]> to String[][]
String[][] result = new String[lines.size()][];
for(int i = 0; i<result.length; i++) {
    result[i] = lines.get(i);
}

System.out.println(Arrays.deepToString(result));

输出:

[[dog, runs, fast], [birds, flies, high], [baby, cries, often, in the evening], [He, works]]

如果您需要我“丢弃”的任何特征，请在评论中告诉我，我将编辑此答案。