Examples of hdfs file operation operations, including uploading files to HDFS, downloading files from HDFS, and deleting files on HDFS. Please refer to it.
The code copy is as follows:
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import java.io.File;
import java.io.IOException;
public class HadoopFile {
private Configuration conf =null;
public HadoopFile(){
conf =new Configuration();
conf.addResource(new Path("/hadoop/etc/hadoop/core-site.xml"));
}
public HadoopFile(Configuration conf){
this.conf =conf;
}
public boolean sendFile(String path,String localfile){
File file=new File(localfile);
if (!file.isFile()) {
System.out.println(file.getName());
return false;
}
try {
FileSystem localFS =FileSystem.getLocal(conf);
FileSystem hadoopFS =FileSystem.get(conf);
Path hadPath=new Path(path);
FSDataOutputStream fsOut=hadoopFS.create(new Path(path+"/"+file.getName()));
FSDataInputStream fsIn=localFS.open(new Path(localfile));
byte[] buf =new byte[1024];
int readbytes=0;
while ((readbytes=fsIn.read(buf))>0){
fsOut.write(buf,0,readbytes);
}
fsIn.close();
fsOut.close();
FileStatus[] hadfiles= hadoopFS.listStatus(hadPath);
for(FileStatus fs :hadfiles){
System.out.println(fs.toString());
}
return true;
} catch (IOException e) {
e.printStackTrace();
}
return false;
}
public boolean delFile(String hadfile){
try {
FileSystem hadoopFS =FileSystem.get(conf);
Path hadPath=new Path(hadfile);
Path p=hadPath.getParent();
boolean rtnval= hadoopFS.delete(hadPath, true);
FileStatus[] hadfiles= hadoopFS.listStatus(p);
for(FileStatus fs :hadfiles){
System.out.println(fs.toString());
}
return rtnval;
} catch (IOException e) {
e.printStackTrace();
}
return false;
}
public boolean downloadFile(String hadfile,String localPath){
try {
FileSystem localFS =FileSystem.getLocal(conf);
FileSystem hadoopFS =FileSystem.get(conf);
Path hadPath=new Path(hadfile);
FSDataOutputStream fsOut=localFS.create(new Path(localPath+"/"+hadPath.getName()));
FSDataInputStream fsIn=hadoopFS.open(hadPath);
byte[] buf =new byte[1024];
int readbytes=0;
while ((readbytes=fsIn.read(buf))>0){
fsOut.write(buf,0,readbytes);
}
fsIn.close();
fsOut.close();
return true;
} catch (IOException e) {
e.printStackTrace();
}
return false;
}
}