1 package com.laowang.utils;
 2 
 3 import org.apache.hadoop.conf.Configuration;
 4 import org.apache.hadoop.fs.FileSystem;
 5 import org.apache.hadoop.hdfs.DistributedFileSystem;
 6 import java.io.IOException;
 7 import java.net.URI;
 8 
 9 /**
10  * @author laowang
11  * @version v1.0.0
12  * @apiNote HDFS 工具类
13  * @since 2018/4/26 10:36
14  */
15 public class HDFSUtil {
16     /**
17      * @author laowang
18      * @version v1.0.0
19      * @apiNote 获取FileSystem
20      * @since 2018/4/26 10:39
21      */
22     public static FileSystem getFileSystem() {
23         FileSystem hdfs = null;
24         //获取配置文件信息
25         Configuration conf = new Configuration();
26         conf.set("fs.hdfs.impl",DistributedFileSystem.class.getName());
27         try {
28             //获取文件系统
29             hdfs = FileSystem.get(URI.create("hdfs://master01:9000"), conf);
30         } catch (IOException e) {
31             e.printStackTrace();
32         }
33         return hdfs;
34     }
35 
36     /**
37      * 关闭文件流
38      * @param fileSystem
39      */
40     public static boolean closeFileSystem(FileSystem fileSystem) {
41         boolean flag = false;
42         if (fileSystem != null) {
43             try {
44                 fileSystem.close();
45                 flag = true;
46             } catch (Exception e) {
47                 e.printStackTrace();
48             }
49         }
50         return flag;
51     }
52 }

 1  /**
 2      * @author laowang
 3      * @version v1.0.0
 4      * @apiNote 上传文件
 5      * @since 2018/4/26 14:14
 6      */
 7     public static void putFile() throws Exception {
 8         Path sourcePath = new Path("E:\\port.txt");
 9         //文件名称
10         Path targetPath = new Path("/test/");
11         //从本地复制文件到文件系统中去
12         hdfs.copyFromLocalFile(sourcePath,targetPath);
13     }

 1     /**
 2      * @author laowang
 3      * @version v1.0.0
 4      * @apiNote 读取文件
 5      * @since  2018/4/26 10:39
 6      */
 7     public static void testRead() throws Exception{
 8         FileSystem hdfs = HDFSUtil.getFileSystem();
 9         //文件名称
10         Path path = new Path("/test/initNetwork.sh");
11         //打开文件输入流
12         FSDataInputStream inputStream = hdfs.open(path);
13         //读取文件到控制台
14         IOUtils.copyBytes(inputStream,System.out,4096,false);
15         //关闭流
16         IOUtils.closeStream(inputStream);
17     }

 1 /**
 2      * @author laowang
 3      * @version v1.0.0
 4      * @apiNote 查看目录
 5      * @since  2018/4/26 14:29 
 6      */
 7     public static void testList() throws Exception{
 8         FileSystem fileSystem=HDFSUtil.getFileSystem();
 9         Path path = new Path("/test/");
10         FileStatus[] fileStatuses = hdfs.listStatus(path);
11         for(FileStatus fileStatus : fileStatuses){
12             Path p = fileStatus.getPath();
13             String info = fileStatus.isDirectory() ? "目录" : "文件";
14             System.out.println(info + ": " + p);
15         }
16     }

 1 /**
 2      * 创建文件
 3      * @throws Exception
 4      */
 5     public static void testDirectory() throws Exception {
 6         FileSystem fileSystem = HDFSUtil.getFileSystem();
 7         Path path = new Path("/test/laowang");
 8         boolean mkdirs = hdfs.mkdirs(path);
 9         System.out.println("创建：" + (mkdirs ? "成功" : "失败"));
10     }

 1  /**
 2      * 创建文件并写入内容
 3      * @throws Exception
 4      */
 5     public static void testCreate() throws Exception{
 6         Path path = new Path("/test/test.txt");
 7         //创建文件
 8         FSDataOutputStream outputStream = hdfs.create(path);
 9         //写入内容
10         outputStream.writeUTF("hello hadoop!");
11         IOUtils.closeStream(outputStream);
12     }

 1     /**
 2      * 重命名
 3      */
 4     public static void testRename() throws Exception{
 5         //原路径
 6         Path srcPath = new Path("/test/test.txt");
 7         //目标路径
 8         Path targetPath = new Path("/test/test2.txt");
 9         boolean rename = hdfs.rename(srcPath, targetPath);
10         System.out.println("重命名：" + (rename ? "成功" : "失败"));
11     }

1   /**
2      * 删除
3      */
4     public static void testDelete() throws Exception {
5         Path path = new Path("/test/test2.txt");
6         boolean b = hdfs.deleteOnExit(path);
7         System.out.println("删除：" + (b ? "成功" : "失败"));
8     }

 1     /**
 2      * @author laowang
 3      * @version v1.0.0
 4      * @apiNote 查找某个文件在HDFS中的位置
 5      * @since  2018/4/26 15:31
 6      */
 7     public static void testLocation() throws Exception{
 8         Path path = new Path("/test/port.txt");
 9         FileStatus fileStatus = hdfs.getFileStatus(path);
10         BlockLocation[] fileBlockLocations = hdfs.getFileBlockLocations(fileStatus, 0, fileStatus.getLen());
11         for(BlockLocation blockLocation : fileBlockLocations){
12             String[] hosts=blockLocation.getHosts();
13             for (String host : hosts) {
14                 System.out.println("端口：" + host);
15             }
16         }
17     }

 1     /**
 2      * @author laowang
 3      * @version v1.0.0
 4      * @apiNote 获取HDFS集群上所有节点名称信息
 5      * @since 2018/4/26 15:38
 6      */
 7     public static void testCluster() throws Exception {
 8         DistributedFileSystem distributedFileSystem = (DistributedFileSystem) hdfs;
 9         DatanodeInfo[] dataNodeStats = distributedFileSystem.getDataNodeStats();
10         for (DatanodeInfo datanodeInfo : dataNodeStats) {
11             System.out.println(datanodeInfo.getHostName());
12         }
13     }