文件分类

package testIO;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class FileList {
	public static void main(String[] args) throws Exception {
		String path="F:\\";//假设目录是F:\
		List<String> fileNames = getFileNames(path);
		Map<Integer,List<String>> map=new HashMap<>();//Integer：第几类文件，List<String>：该类文件下的文件名
		int i=0;
		while(!fileNames.isEmpty()){
			String newPath=path+i+"\\";
			File dir=new File(newPath);
			if(dir.isDirectory()){
				if(dir.exists()){
					dir.delete();
				}
			}

			dir.mkdir();
			List<String> list=new ArrayList<>();
			list.add(fileNames.get(0));
			copyFileToDir(fileNames.get(0), path, newPath);
			if(fileNames.size()>1){
				for(int j=fileNames.size()-1;j>=1;j--){
					boolean flag = compareFiles(path+fileNames.get(0), path+fileNames.get(j));
					if(flag){
						copyFileToDir(fileNames.get(i), path, newPath);
						list.add(fileNames.get(j));
						fileNames.remove(j);
					}
				}
			}
			fileNames.remove(0);
			map.put(i, list);
			i++;
		}
		
		Set<Integer> keySet = map.keySet();
		for(Integer integer:keySet){
			System.out.println(integer+":");
			List<String> list = map.get(integer);
			for(String string:list){
				System.out.print(string+"  ");
			}
			System.out.println();
		}
	}
	
	public static void copyFileToDir(String fileName,String oldPath,String newPath) throws Exception{
		FileInputStream fileInputStream=new FileInputStream(oldPath+fileName);
		File file=new File(newPath+fileName);
		if(file.exists()){
			file.delete();
		}
		FileOutputStream fileOutputStream=new FileOutputStream(new File(newPath+fileName));
		int length=fileInputStream.available();
		byte[] buf=new byte[length];
		fileInputStream.read(buf);
		fileOutputStream.write(buf);
		fileInputStream.close();
		fileOutputStream.flush();
		fileOutputStream.close();
	}
	
	public static List<String> getFileNames(String path){
		File file=new File("F:\\");
		File[] listFiles = file.listFiles();
		List<String> list=new ArrayList<>();
		for(File file2:listFiles){
			if(file2.getName().endsWith("txt")){
				list.add(file2.getName());
			}
		}
		return list;
	}
	
	public static boolean compareFiles(String file1,String file2) throws Exception{
		FileInputStream inputStream1=new FileInputStream(file1);
		FileInputStream inputStream2=new FileInputStream(file2);
		int length1=inputStream1.available();
		int length2=inputStream2.available();
		if(length1!=length2){
			inputStream1.close();
			inputStream2.close();
			return false;
		}else{
			byte[] buf1=new byte[length1];
			byte[] buf2=new byte[length1];
			inputStream1.read(buf1);
			inputStream2.read(buf2);
			inputStream1.close();
			inputStream2.close();
			for(int i=0;i<length1;i++){
				if(buf1[i]!=buf2[i]){
					return false;
				}
			}
			return true;
		}
		
		
		
	}

}