java - 如何合并两个文本文件中的数据

Question

我有两个相关的文本文件，例如 data1.txt 和 data2.txt。我想合并这两个文件以创建 result.txt。知道如何解决这个问题吗？

数据1.txt

books, 3
Shelf, 5
groceries,6
books, 1
Shelf, 2

数据2.txt

books,2
shelf,3
groceries,1

结果.txt

books, 3, 2
Shelf, 5,3
groceries,6,1
books, 1,2
Shelf, 2, 3

Answer 1

这是给你的一个例子。首先你需要从 data2 文本文件向 2d list 添加值。然后当 file2 中的行为 null 时，你可以从中获取相对于它的文本的映射值列表。所以我有一个方法可以返回一个字符串的映射值。代码比我想象的要长。我在这里只发布相关的方法。 This is link to complete class file

public void marged(){
    try {
        BufferedReader br1 = null;
        BufferedReader br2 = null;

        String line1;
        String line2;
        ArrayList<ArrayList<String>> arrayList = new ArrayList<>();

        br1 = new BufferedReader(new FileReader("C:\\Users\\Madhawa.se\\Desktop\\workingfox\\data1.txt"));
        br2 = new BufferedReader(new FileReader("C:\\Users\\Madhawa.se\\Desktop\\workingfox\\data2.txt"));

        while ((line1 = br1.readLine()) != null) {

            String[] split1 = line1.split(",");

            String line1word = split1[0].trim();
            String line1val = split1[1].trim();

            line2 = br2.readLine();

            if (line2 != null) {
                String[] split2 = line2.trim().split(",");

                String line2word = split2[0].trim();
                String line2val = split2[1].trim();

                ArrayList<String> list = new ArrayList();
                list.add(line2word);
                list.add(line2val);
                arrayList.add(list);

                if (line1word.equalsIgnoreCase(line2word)) {
                    String ok = line1word + "," + line1val + "," + line2val;
                    System.out.println(ok);
                }

            } else {
                String ok = line1word + "," + line1val + "," + doesexist(arrayList, line1word);
                System.out.println(ok);
            }

        }

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

这是方法返回映射值

public String doesexist(ArrayList<ArrayList<String>> arrayList, String s) {

    for (int i = 0; i < arrayList.size(); i++) {
        String get = arrayList.get(i).get(0);
        if (get.trim().equalsIgnoreCase(s.trim())) {
            return arrayList.get(i).get(1);
        }
    }
    return "-1";
 }

输出>>

books,3,2
Shelf,5,3
groceries,6,1
books,1,2
Shelf,2,3