package com.bigdata.mapreduce.utils;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.* ;
public class HDFSUtil {
  private static String hdfsURL="hdfs://localhost:9000";
  private static Configuration conf;
  static {
    conf = new Configuration();
    conf.set("fs.defaultFS", hdfsURL);
  }
  // 从HDFS上下载文件
  public static void downloadFromHDFS(String remoteFile,String localFile) throws Exception {
      FileSystem fs = FileSystem.get(conf);
      Path remotePath = new Path(remoteFile);
      Path localPath = new Path(localFile);
      fs.copyToLocalFile(remotePath, localPath);
      fs.close();
  }
  // 上传文件到HDFS
  public static void uploadToHDFS(String localfile,String remotefile) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path remotePath = new Path(remotefile);
    Path localPath = new Path(localfile);
    fs.copyFromLocalFile(localPath, remotePath);
    fs.close();
  }
  // 创建HDFS文件夹
  public static void createDirFromHDFS(String remoteDir) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path remotePath = new Path(remoteDir);
    //调用mkdirs函数创建目录
    fs.mkdirs(remotePath);
    fs.close();
  }
  // 删除文件和文件夹
  public static void deleteFromHDFS(String remoteDir) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path remotePath = new Path(remoteDir);
    //调用mkdirs函数创建目录,true表示循环递归删除
    fs.delete(remotePath, true);
    fs.close();
  }
  // 重命名文件
  public static void renameFromHDFS(String oldName, String newName) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path hdfsOldName = new Path(oldName);
    Path hdfsNewName = new Path(newName);
    fs.rename(hdfsOldName, hdfsNewName);
    fs.close();
  }
  // 查看文件夹
  public static void ListHDFSDir(String remoteDir) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path dirPath = new Path(remoteDir);
    /*递归获取目录下的所有文件*/
    RemoteIterator<LocatedFileStatus> remoteIterator = fs.listFiles(dirPath, true);
    /*输出每个文件的信息*/
    while (remoteIterator.hasNext()) {
      FileStatus s = remoteIterator.next();
      System.out.println("路径: " + s.getPath().toString());
      System.out.println("权限: " + s.getPermission().toString());
      System.out.println("大小: " + s.getLen());
      /*返回的是时间戳,转化为时间日期格式*/
      Long timeStamp = s.getModificationTime();
      SimpleDateFormat format = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss");
      String date = format.format(timeStamp);
      System.out.println("时间: " + date);
      System.out.println();
    }
    fs.close();
  }
  // 列出文件
  public static List<String> listRemoteDirAndFiles(String remoteDir) throws Exception {
    List<String> remoteDirList = new ArrayList<>();
    FileSystem fs = FileSystem.get(conf);
    Path dirPath = new Path(remoteDir);
    /*递归获取目录下的所有文件*/
    RemoteIterator<LocatedFileStatus> remoteIterator = fs.listFiles(dirPath, true);
    /*输出每个文件的信息*/
    while (remoteIterator.hasNext()) {
      FileStatus s = remoteIterator.next();
      String myPath = s.getPath().toString().substring(21);
      remoteDirList.add(myPath);
    }
    fs.close();
    return remoteDirList;
  }
  // 列出文件夹
  public static List<String> listRemoteDir(String remoteDir) throws Exception {
    List<String> remoteDirList = new ArrayList<>();
    FileSystem fs = FileSystem.get(conf);
    Path dirPath = new Path(remoteDir);
    FileStatus[] fileStatus = fs.listStatus(dirPath);
    for (FileStatus file : fileStatus) {
      if (file.isDirectory()) {
        listRemoteDir(file.getPath().toString());
        remoteDirList.add(file.getPath().toString().substring(21));
      } else {
        remoteDirList.add(file.getPath().toString().substring(21));
      }
    }
    fs.close();
    return remoteDirList;
  }
  // 移动文件夹
  public static void moveDirFromHDFS(String oldPath, String newPath) throws Exception {
    FileSystem fs = FileSystem.get(conf);
    Path hdfsOldName = new Path(oldPath);
    Path hdfsNewName = new Path(newPath);
    fs.rename(hdfsOldName, hdfsNewName);
    fs.close();
  }
  // 测试
//  public static void main(String[] args) {
//    try {
      // 1、列出文件
//      List<String> list = HDFSUtil.listRemoteDirAndFiles("/");
//      for (int i = 0; i < list.size(); i++) {
//        System.out.println(list.get(i));
//      }
      // 2、重名文件
//      HDFSUtil.renameFromHDFS("/start-dfs.cmd", "/start-dfs.sh");
      // 3、创建文件夹
//      HDFSUtil.createDirFromHDFS("/hive");
      // 4、移动文件夹（把/路径下的hive文件夹，放到/user路径）
//      HDFSUtil.moveDirFromHDFS("/hive", "/user");
      // 5、删除文件或者文件夹
//      HDFSUtil.deleteFromHDFS("/user");
//      HDFSUtil.deleteFromHDFS("/user/hive/start-dfs.sh");
//    } catch (Exception e) {
//      e.printStackTrace();
//    }
//  }
}