DuplicateFileRemover.java

import java.io.File;
import java.io.FileNotFoundException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.FileInputStream;

/**
 * @author David Newton
 *
 * Scans the user's default downloads directory for duplicate files and removes them.
 */
public class DuplicateFileRemover {

    public static void main(String[] args) {
        int num_files = 0;
        Path userPath = Paths.get(System.getProperty("user.home"), "Downloads");
        File dir = new File(userPath.toString());
        File[] fileList = dir.listFiles();

        for (int i = 0; i < fileList.length; i++) {
            for (int j = i + 1; j < fileList.length; j++) {
                if (fileList[i].length() == fileList[j].length()) {
                    if (CompareFiles(fileList[i], fileList[j])) {
                        try {
                            System.out.println("> Duplicate Found: " + fileList[j].getName());
                            fileList[j].delete();
                            System.out.println("> File Deleted.");
                            num_files++;
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
        System.out.println("> Finished.");
        System.out.println("> "
            num_files + " duplicate files removed.");
    }

    private static boolean CompareFiles(File file, File file2) {
        try {
            FileInputStream fileStream = new FileInputStream(file);
            FileInputStream fileStream2 = new FileInputStream(file2);

            boolean result = true;
            while (result == true) {
                int fileb = fileStream.read();
                @SuppressWarnings("unused")
                int fileb2 = fileStream2.read();
                if (fileStream.read() != fileStream2.read()) {
                    result = false;
                    break;
                }
                if (fileb == -1) //EOF
                    break;
            }

            fileStream.close();
            fileStream2.close();
            return result;

        } catch (FileNotFoundException e) {
            return false;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
}