在.txt文件中搜索字符串并获取Java中的行和列编号

我现在遇到了一个问题。我应该写一个程序，能够搜索作为参数给出的.txt文件中的字符串。程序必须返回找到的字符串的行和列。 我正在努力寻找一种方法来实现这一点，但我不知道如何继续下去。我很高兴收到你的来信

以下是我在处理我的任务时的尝试： -我曾考虑过通过字符串数组中的缓冲读取器保存文件内容，但这似乎不起作用，因为我无法从一开始就定义数组的长度 -我还考虑通过缓冲读取器将文件内容保存为字符串，然后将该字符串拆分为字符。但是，我不确定如何才能检索原始文件中的行

这是我目前拥有的非功能性代码：

public class StringSearch{
    public static void main(String[] args){
        if(args.length > 0){
            BufferedReader br = null;
            String text = null;
            try{
                br = new BufferedReader(new FileReader(args[0]));
                // attempt of saving the content of the "argument" file in a string array and then in a        string
                String[] lines = new String[]; // I know this does not work like this 
                for( int i = 0; i < lines.length; i++){
                    lines[i] = br.readLine;
                    text = text + lines[i];
                    i++;
                }
                text.split("\r\n");

            } catch (IOException ioe){
                ioe.printStackTrace();
            } finally{
                if (br != null) {
                    try{
                        br.close();
                    }catch (IOException ioe){
                        ioe.printStackTrace();
                    }
                }


            }

        }
    }
}

公共类字符串搜索{
公共静态void main（字符串[]args）{
如果（args.length>0）{
BufferedReader br=null；
字符串文本=空；
试一试{
br=新的BufferedReader（新的文件读取器（args[0]）；
//尝试将“参数”文件的内容保存在字符串数组中，然后保存在字符串中
String[]lines=new String[]；//我知道它不是这样工作的
对于（int i=0；i

这里有一种方法-

让我们考虑一个计数器，它为所有的计数器保存一个计数器。

readLine（）

方法调用-表示.txt中的“行” 文件因此，在 while循环

接下来，拆分“”上的行（空格），以获得 线路。然后，您可以迭代该数组并将单词与 搜索字符串。匹配时数组索引的位置 找到的将表示“列”

---

您可以按如下方式进行操作：

import java.io.File;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        if (args.length != 2) {
            System.out.println("The correct syntax to use this program is: java Main <filename.txt> <text-to-search>");
            return;
        }
        Scanner scanner;
        File file = new File(args[0]);
        int rowCount = 1, index;
        String line;

        // Map to collect row and col info of the search string
        Map<String, String> lineColMap = new HashMap<String, String>();

        if (!file.exists()) {
            System.out.println("The file, " + args[0] + " does not exist");
            return;
        }
        try {
            scanner = new Scanner(file);
            while (scanner.hasNextLine()) {// Loop until the last line in the file
                line = scanner.nextLine();// Read a line from the file
                index = line.indexOf(args[1]);// Find if the string exists in the line
                if (index != -1) {// If the string exists
                    // Put the row and col info of the search string into the map
                    lineColMap.put("Row: " + rowCount, "Column: " + index);
                }
                rowCount++;// Increase the row count
            }
        } catch (Exception e) {
            System.out.println("Error occured while processing the file");
            e.printStackTrace();
        }
        if (lineColMap.entrySet().size() > 0) {// If there is at least one entry collected into the map
            System.out.println("'" + args[1] + "' exists in " + args[0] + " as follows:");
            for (Map.Entry<String, String> entry : lineColMap.entrySet()) {
                System.out.println(entry.getKey() + ", " + entry.getValue());
            }
        } else {
            System.out.println("'" + args[1] + "' does not exist in " + args[0]);
        }
    }
}

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It is a privately held website, the flagship site of the Stack Exchange Network, created in 2008 by Jeff Atwood and Joel Spolsky.
It features questions and answers on a wide range of topics in computer programming.
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input.txt

的内容如下：

import java.io.File;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        if (args.length != 2) {
            System.out.println("The correct syntax to use this program is: java Main <filename.txt> <text-to-search>");
            return;
        }
        Scanner scanner;
        File file = new File(args[0]);
        int rowCount = 1, index;
        String line;

        // Map to collect row and col info of the search string
        Map<String, String> lineColMap = new HashMap<String, String>();

        if (!file.exists()) {
            System.out.println("The file, " + args[0] + " does not exist");
            return;
        }
        try {
            scanner = new Scanner(file);
            while (scanner.hasNextLine()) {// Loop until the last line in the file
                line = scanner.nextLine();// Read a line from the file
                index = line.indexOf(args[1]);// Find if the string exists in the line
                if (index != -1) {// If the string exists
                    // Put the row and col info of the search string into the map
                    lineColMap.put("Row: " + rowCount, "Column: " + index);
                }
                rowCount++;// Increase the row count
            }
        } catch (Exception e) {
            System.out.println("Error occured while processing the file");
            e.printStackTrace();
        }
        if (lineColMap.entrySet().size() > 0) {// If there is at least one entry collected into the map
            System.out.println("'" + args[1] + "' exists in " + args[0] + " as follows:");
            for (Map.Entry<String, String> entry : lineColMap.entrySet()) {
                System.out.println(entry.getKey() + ", " + entry.getValue());
            }
        } else {
            System.out.println("'" + args[1] + "' does not exist in " + args[0]);
        }
    }
}

Stack Overflow is a question and answer site for professional and enthusiast programmers.
It is a privately held website, the flagship site of the Stack Exchange Network, created in 2008 by Jeff Atwood and Joel Spolsky.
It features questions and answers on a wide range of topics in computer programming.
It was created to be a more open alternative to earlier question and answer sites such as Experts-Exchange.
The name for the website was chosen by voting in April 2008 by readers of Coding Horror, Atwood's popular programming blog.

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代码中的逻辑是直截了当的，我相信，您应该能够在第一次阅读时理解它。如果有任何疑问，请随时发表评论。

非常感谢您的回答。我还不清楚我应该先对课文做些什么。我应该读取行并将它们保存到字符串或字符串数组中吗？什么是可取的？您可以动态解析文本。并且仅在找到匹配项时存储“行”和“列”值。如果有多个匹配项，您可以使用相关的数据结构来存储这些数据。非常感谢您的输入和全面的帮助！选择HashMap来存储行和列的编号是很巧妙的，但我不明白它是如何工作的。HashMap是为字符串声明的，而rowCount和index是整数，对吗？你能解释一下吗？提前多谢！我只在地图中存储了字符串，例如，第一个条目是

行：1=列：51

，其中

行：1

是键，

列：51

是值；它们都是字符串。如果只想存储数字（行号和列号），可以将映射声明为

map lineColMap=newhashmap（）lineColMap.put（行数，索引）

将值存储到地图中。如果有任何进一步的疑问，请随时发表评论。这是有道理的。再次感谢！最后一个关于int rowCount的问题。您将其初始化为int rowCount=1，index；这是否意味着它有两个价值观？非常欢迎<代码>整数行计数=1，索引是在一条语句中声明两个或多个变量的快捷方式。您还可以将其编写为

int rowCount=1；整数指数作为两个单独的语句。在这两种方式中的任何一种方式中，
rowCount
将用
1
初始化，
index
将用
0
初始化（这是
int
变量的默认值）。如有任何疑问，请随时发表评论。