1.查看HDFS下所有的文件存储位置信息
1 package Hdfs;HDFS下所有文件存储位置
2
3 import java.net.URI;
4 import org.apache.hadoop.conf.Configuration;
5 import org.apache.hadoop.fs.BlockLocation;
6 import org.apache.hadoop.fs.FileStatus;
7 import org.apache.hadoop.fs.FileSystem;
8 import org.apache.hadoop.fs.Path;
9
10 public class LocationFile {
11 public static void main(String[] args) throws Exception {
12 String uri = "hdfs://neusoft-master:9000/user/root/test/demo1";
13 Configuration conf = new Configuration();
14 try {
15 FileSystem fs = FileSystem.get(URI.create(uri), conf);
16 Path fpath = new Path(uri);
17 FileStatus fileStatus = fs.getFileStatus(fpath);
18 BlockLocation[] blockLocations = fs.getFileBlockLocations(
19 fileStatus, 0, fileStatus.getLen());
20 int blocklen = blockLocations.length;
21 for (int i = 0; i < blocklen; i++) {
22 String[] hosts = blockLocations[i].getHosts();
23 System.out.println("block_" +i+ "_location:" + hosts[0]);
24 }
25 } catch (Exception e) {
26 e.printStackTrace();
27 }
28 }
29 }
2.提交jar包,并分析运行结果
3.这里的显示结果:
block_0_location:neusoft-master
分别为:块号:主机名,因为HDFS的文件是由Data块完成的,Hadoop中得block块一般64M
Hadoop2中block块为128M。(单独分析block块)