我写了一个文件复制处理器，它获取每个文件的MD5哈希值，将其添加到一个哈希Map中，然后获取所有具有相同哈希值的文件，并将其添加到一个名为dupeList的哈希Map中。

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.nio.file.Files.read(Unknown Source)
at java.nio.file.Files.readAllBytes(Unknown Source)
at com.embah.FileDupe.Utils.FileUtils.getMD5Hash(FileUtils.java:14)
at com.embah.FileDupe.FileDupe.getDuplicateFiles(FileDupe.java:43)
at com.embah.FileDupe.FileDupe.getDuplicateFiles(FileDupe.java:68)
at ImgHandler.main(ImgHandler.java:14)

我敢肯定这是由于它处理这么多文件的事实，但我不知道一个更好的方式来处理它。我试图让这个工作，这样我就可以筛选通过所有我的孩子的婴儿照片，并删除重复之前，我把他们放在我的外部硬盘驱动器长期存储。感谢大家的帮助！
我的代码

public class FileUtils {
public static String getMD5Hash(String path){
    try {
        byte[] bytes = Files.readAllBytes(Paths.get(path)); //LINE STACK THROWS ERROR
        byte[] hash = MessageDigest.getInstance("MD5").digest(bytes);
        bytes = null;
        String hexHash = DatatypeConverter.printHexBinary(hash);
        hash = null;
        return hexHash;
    } catch(Exception e){
        System.out.println("Having problem with file: " + path);
        return null;
    }
}

public class FileDupe {
public static Map<String, List<String>> getDuplicateFiles(String dirs){
    Map<String, List<String>> allEntrys = new HashMap<>(); //<hash, file loc>
    Map<String, List<String>> dupeEntrys = new HashMap<>();
    File fileDir = new File(dirs);
    if(fileDir.isDirectory()){
        ArrayList<File> nestedFiles = getNestedFiles(fileDir.listFiles());
        File[] fileList = new File[nestedFiles.size()];
        fileList = nestedFiles.toArray(fileList);

        for(File file:fileList){
            String path = file.getAbsolutePath();
            String hash = "";
            if((hash = FileUtils.getMD5Hash(path)) == null)
                continue;
            if(!allEntrys.containsValue(path))
                put(allEntrys, hash, path);
        }
        fileList = null;
    }
    allEntrys.forEach((hash, locs) -> {
        if(locs.size() > 1){
            dupeEntrys.put(hash, locs);
        }
    });
    allEntrys = null;
    return dupeEntrys;
}

public static Map<String, List<String>> getDuplicateFiles(String... dirs){
    ArrayList<Map<String, List<String>>> maps = new ArrayList<Map<String, List<String>>>();
    Map<String, List<String>> dupeMap = new HashMap<>();
    for(String dir : dirs){ //Get all dupe files
        maps.add(getDuplicateFiles(dir));
    }
    for(Map<String, List<String>> map : maps){ //iterate thru each map, and add all items not in the dupemap to it
        dupeMap.putAll(map);
    }
    return dupeMap;
}

protected static ArrayList<File> getNestedFiles(File[] fileDir){
    ArrayList<File> files = new ArrayList<File>();
    return getNestedFiles(fileDir, files);
}

protected static ArrayList<File> getNestedFiles(File[] fileDir, ArrayList<File> allFiles){
    for(File file:fileDir){
        if(file.isDirectory()){
            getNestedFiles(file.listFiles(), allFiles);
        } else {
            allFiles.add(file);
        }
    }
    return allFiles;
}

protected static <KEY, VALUE> void put(Map<KEY, List<VALUE>> map, KEY key, VALUE value) {
    map.compute(key, (s, strings) -> strings == null ? new ArrayList<>() : strings).add(value);
}

public class ImgHandler {
private static Scanner s = new Scanner(System.in);

public static void main(String[] args){
    System.out.print("Please enter locations to scan for dupelicates\nSeperate Location via semi-colon(;)\nLocations: ");
    String[] locList = s.nextLine().split(";");
    Map<String, List<String>> dupes = FileDupe.getDuplicateFiles(locList);
    System.out.println(dupes.size() + " dupes detected!");
    dupes.forEach((hash, locs) -> {
        System.out.println("Hash: " + hash);
        locs.forEach((loc) -> System.out.println("\tLocation: " + loc));
    });
}