package com.vci.common.file;

import java.io.File;
import java.io.FileInputStream;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.util.HashMap;
import java.util.Map;

public class FileDigest {
  /**
   * 获取单个文件的MD5值！
   * @param file
   * @return
   */
  public String getFileMD5(String filePath) {
	  File file=new File(filePath);
      if (!file.isFile()){
          return null;
      }
      MessageDigest digest = null;
      FileInputStream in=null;
      byte buffer[] = new byte[1024];
      int len;
      try {
         digest = MessageDigest.getInstance("MD5");
         in = new FileInputStream(file);
         while ((len = in.read(buffer, 0, 1024)) != -1) {
         digest.update(buffer, 0, len);
       }
         in.close();
       } catch (Exception e) {
          e.printStackTrace();
          return null;
       }
       BigInteger bigInt = new BigInteger(1, digest.digest());
       return bigInt.toString(16);
  }
  
  /**
   * 获取文件夹中文件的MD5值
   * @param file
   * @param listChild ;true递归子目录中的文件
   * @return
   */
  public Map<String, String> getDirMD5(String filePath,boolean listChild) {
	 File file=new File(filePath);
     if(!file.isDirectory()){
        return null;
     }
     //<filepath,md5>
     Map<String, String> map=new HashMap<String, String>();
     String md5;
     File files[]=file.listFiles();
     for(int i=0;i<files.length;i++){
        File f=files[i];
        String fileList=f.getPath();
        if(f.isDirectory()&&listChild){
              map.putAll(getDirMD5(fileList, listChild));
        } else {
              md5=getFileMD5(fileList);
              if(md5!=null){
                   map.put(f.getPath(), md5);
               }
        }
      }
      return map;
  }
}