1、創(chuàng)建目錄import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class MakeDir {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/20130709");
fs.create(path);
fs.close();
}
}
2、刪除目錄
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class DeleteDir {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/20130710");
fs.delete(path);
fs.close();
}
}
3、寫文件
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class WriteFile {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/write.txt");
FSDataOutputStream out = fs.create(path);
out.writeUTF("da jia hao,cai shi zhen de hao!");
fs.close();
}
}
4、讀文件
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class ReadFile {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/write.txt");
if(fs.exists(path)){
FSDataInputStream is = fs.open(path);
FileStatus status = fs.getFileStatus(path);
byte[] buffer = new byte[Integer.parseInt(String.valueOf(status.getLen()))];
is.readFully(0, buffer);
is.close();
fs.close();
System.out.println(buffer.toString());
}
}
}
5、上傳本地文件到HDFS
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class CopyFromLocalFile {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path src = new Path("/home/hadoop/word.txt");
Path dst = new Path("/user/hadoop/data/");
fs.copyFromLocalFile(src, dst);
fs.close();
}
}
6、刪除文件
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class DeleteFile {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/word.txt");
fs.delete(path);
fs.close();
}
}
7、獲取給定目錄下的所有子目錄以及子文件
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class GetAllChildFile {
static Configuration conf = new Configuration();
public static void main(String[] args)throws IOException {
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop");
getFile(path,fs);
//fs.close();
}
public static void getFile(Path path,FileSystem fs) throws IOException {
FileStatus[] fileStatus = fs.listStatus(path);
for(int i=0;i<fileStatus.length;i++){
if(fileStatus[i].isDir()){
Path p = new Path(fileStatus[i].getPath().toString());
getFile(p,fs);
}else{
System.out.println(fileStatus[i].getPath().toString());
}
}
}
}
8、查找某個(gè)文件在HDFS集群的位置
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
public class FindFile {
public static void main(String[] args) throws IOException {
getFileLocal();
}
/**
* 查找某個(gè)文件在HDFS集群的位置
* @Title:
* @Description:
* @param
* @return
* @throws
*/
public static void getFileLocal() throws IOException{
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("/user/hadoop/data/write.txt");
FileStatus status = fs.getFileStatus(path);
BlockLocation[] locations = fs.getFileBlockLocations(status, 0, status.getLen());
int length = locations.length;
for(int i=0;i<length;i++){
String[] hosts = locations[i].getHosts();
System.out.println("block_" + i + "_location:" + hosts[i]);
}
}
}
9、HDFS集群上所有節(jié)點(diǎn)名稱信息
package com.hadoop.file;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
public class FindFile {
public static void main(String[] args) throws IOException {
getHDFSNode();
}
/**
* HDFS集群上所有節(jié)點(diǎn)名稱信息
* @Title:
* @Description:
* @param
* @return
* @throws
*/
public static void getHDFSNode() throws IOException{
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
DistributedFileSystem dfs = (DistributedFileSystem)fs;
DatanodeInfo[] dataNodeStats = dfs.getDataNodeStats();
for(int i=0;i<dataNodeStats.length;i++){
System.out.println("DataNode_" + i + "_Node:" + dataNodeStats[i].getHostName());
}
}
}
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