我如何提取包含特殊关键字的行并将这些行打印到单独的文本文件中？

Question

首先，我在寻找问题的答案，但没有找到确切的答案。所以我在不同的文件夹和子文件夹中有很多 .log 文件（文本文档）。我在不同的文件夹中有很多很多 .log 文件。如果它们是三个关键字之一，我希望整行符合以下条件的一个单独的文本文档：

我想查看 .log 文件中该行的行号
我想看看线路

我知道我的代码还没有完成，但我不知道如何继续。

如果我运行我的代码，我总是看到字母之间的空白。为什么？

感谢所有有用的答案！

public static void main(String[] args) {

    // declare folder
    File folder = new File("path");

    if (!folder.exists()) {
        System.out.println("folder not existing");
    }
    listAllFilesForFolder(folder);
}

public static void listAllFilesForFolder(File folder) {
    // for each file in folder
    for (File fileEntry : folder.listFiles()) {
        // if file is another folder
        if (fileEntry.isDirectory()) {
            // step into that folder recursively
            listAllFilesForFolder(fileEntry);
        } else {
            // its a file
            String filePath = fileEntry.getAbsolutePath();
            System.out.println("File is: " + filePath);
            parseFile(filePath);
        }
    }
}

public static void parseFile(String file) {
    BufferedReader reader;
    try {

        int LineCount = 0;
        // String line1 = "";

        reader = new BufferedReader(new FileReader(file));
        File folderError = new File("ErrorFolder");
        PrintWriter out = new PrintWriter("filename1.txt");
        // for each line in file
        String line = reader.readLine();
        while (line != null) {

            folderError.mkdir(); // create a folder in your current work space

            LineCount++;

            // print line
            System.out.println("line is: " + LineCount + " " + line);
            // TODO if line has an error, ... do something
            // read next line
            line = reader.readLine();

            out.println(line);
        }
        out.close();

        reader.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

Answer 1

如果您使用 org.apache.commons.io.FileUtils 执行以下操作：

package com.test;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.DirectoryFileFilter;
import org.apache.commons.io.filefilter.TrueFileFilter;

import java.io.BufferedReader;
import java.io.File;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.List;


public class SearchInFilesAndDirectory {

    private static int lineNumber = 0;

    private static final String FOLDER_PATH = "path_to_file";

    public static void main(String[] args) {

        File dir = new File(FOLDER_PATH);

        List<File> files = (List<File>) FileUtils.listFiles(dir, TrueFileFilter.INSTANCE, DirectoryFileFilter.DIRECTORY);

        for (File file : files) {

            if (file.isFile()) {

                try (BufferedReader br = Files.newBufferedReader(file.toPath(), StandardCharsets.UTF_8)) {

                    String line;
                    while ((line = br.readLine()) != null) {
                        lineNumber++;
                        if (line.contains("word")) {
                            System.out.println("Keyword found in " + file.toPath() + " at line " + lineNumber + ".\n" + line.trim());
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

上面会打印出路径和行号，即

Keyword found in /path/test/childFolder/test.txt at line 3.
3       Keyword test
Keyword found in /path/test/testFile.txt at line 5.
1       keyword ----

我如何提取包含特殊关键字的行并将这些行打印到单独的文本文件中？

How i extract lines that includes special keywords and print the lines to a seperate text file?

java

search

extract

bufferedreader