学习Java和Linux脚本操作的实用案例研究

public class StringReverse {
    public static String reverse(String str) {
        StringBuilder sb = new StringBuilder(str);
        return sb.reverse().toString();
    }
    
    public static void main(String[] args) {
        String str = "Hello, World!";
        String reversedStr = reverse(str);
        System.out.println(reversedStr);
    }
}

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class FileIO {
    public static void copyFile(String sourcePath, String destinationPath) throws IOException {
        try (BufferedReader reader = new BufferedReader(new FileReader(sourcePath));
             BufferedWriter writer = new BufferedWriter(new FileWriter(destinationPath))) {
             
            String line;
            while ((line = reader.readLine()) != null) {
                writer.write(line);
                writer.newLine();
            }
        }
    }
    
    public static void main(String[] args) {
        String sourcePath = "source.txt";
        String destinationPath = "destination.txt";
        
        try {
            copyFile(sourcePath, destinationPath);
            System.out.println("File copied successfully.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

#!/bin/bash
dir=$1
totalLines=0
for file in $(find $dir -type f -name '*.txt'); do
    lines=$(wc -l < $file)
    totalLines=$((totalLines + lines))
done
echo "Total lines: $totalLines"

#!/bin/bash
sourceDir=/path/to/source
backupDir=/path/to/backup
timestamp=$(date +%Y%m%d%H%M%S)
backupDirName=${backupDir}/backup_${timestamp}
mkdir -p $backupDirName
cp -R $sourceDir/* $backupDirName
echo "Backup created at $backupDirName"