发现同一文件夹下的重复文件

import java.io.*;
import java.util.*;

public class FindDuplicatedFile {

        //fileList is the list of files in this directory
    static private List<File> fileList = new ArrayList<>();



    static private void getFileList(String filePath)
            throws NotDirectoryExpectation{

        File file = new File(filePath);
        if(!file.isDirectory()){
            throw new NotDirectoryExpectation();
        }

        File[] fileArray = file.listFiles();
        if(fileArray == null) return;

        for(int i = 0; i<fileArray.length; i++){
            if(fileArray[i].isFile())
                fileList.add(fileArray[i]);

            if(fileArray[i].isDirectory())
                getFileList(fileArray[i].getAbsolutePath());
        }
    }



        //to search the directory to find duplicate files
    public static List<File> getDuplicatedFile(String filePath)
                     throws NotDirectoryExpectation{
        getFileList(filePath);
        List<File > duplicateFiles = new ArrayList<>();

        for(int i = 0; i< fileList.size(); i++){
            File temp = fileList.get(i);
            for(int j = i+1; j < fileList.size(); j++){
                if(fileList.get(j).getName().equals(temp.getName())
                        && fileList.get(j).length() == temp.length()) {
                    duplicateFiles.add(fileList.get(j));
                    duplicateFiles.add(temp);
                }
            }
        }

        return duplicateFiles;
    }

    public static void printDuplicates(List<File> list){

        Iterator<File> it = list.iterator();

        if(list.size() == 0){
            System.out.println("no Duplicated File!");
        }
        while(it.hasNext()){
            File temp= it.next();
            System.out.println(temp.getName() + '	' +
                    temp.getAbsolutePath() + '	' + temp.length());
        }
    }

    public static void main(String[] args){
        String filePath = args[0];
        try {
            printDuplicates(getDuplicatedFile(filePath));
        }catch (Exception e){}

    }
    static private class NotDirectoryExpectation extends Exception{}
}

这个主要就是File类的使用了