在文件中搜索字符串并在找到时返回该字符串 [英] Search a file for a String and return that String if found

问题描述

如何在 txt 文件中搜索用户输入的字符串，然后将该字符串返回到控制台.我在下面写了一些不起作用的代码，但我希望它可以说明我的观点...

How can you search through a txt file for a String that the user inputs and then return that String to the console. I've written some code that doesn't work below, but I hope it can illustrate my point...

public static void main(String[] args) {
  searchforName();
}

   private static void searchForName() throws FileNotFoundException {
    File file = new File("leaders.txt");
    Scanner kb = new Scanner(System.in);
    Scanner input = new Scanner(file);

    System.out.println("Please enter the name you would like to search for: ");
    String name = kb.nextLine();


    while(input.hasNextLine()) {
        System.out.println(input.next(name));
    }
}

leaders.txt"文件包含一个名字列表.

The "leaders.txt" file contains a list of names.

推荐答案

您可以创建一个单独的 Scanner 来逐行读取文件并以这种方式进行匹配...

You can create a seperate Scanner to read the file line by line and do a match that way...

final Scanner scanner = new Scanner(file);
while (scanner.hasNextLine()) {
   final String lineFromFile = scanner.nextLine();
   if(lineFromFile.contains(name)) { 
       // a match!
       System.out.println("I found " +name+ " in file " +file.getName());
       break;
   }
}

关于您应该使用Scanner 还是BufferedReader 来读取文件，请阅读此答案.

With regards to whether you should use a Scanner or a BufferedReader to read the file, read this answer.

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