package org.conan.myhadoop.hdfs;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.mapred.JobConf;
public class HdfsDAO {
private static final String HDFS = "hdfs://192.168.1.210:9000/";
public HdfsDAO(Configuration conf) {
this(HDFS, conf);
}
public HdfsDAO(String hdfs, Configuration conf) {
this.hdfsPath = hdfs;
this.conf = conf;
}
private String hdfsPath;
private Configuration conf;
public static void main(String[] args) throws IOException {
JobConf conf = config();
HdfsDAO hdfs = new HdfsDAO(conf);
// hdfs.copyFile("datafile/item.csv", "/tmp/new");
// hdfs.ls("/tmp/new");
hdfs.rename("/user/hdfs/pagerank/tmp3", "/user/hdfs/pagerank/tmp4");
}
public static JobConf config() {
JobConf conf = new JobConf(HdfsDAO.class);
conf.setJobName("HdfsDAO");
conf.addResource("classpath:/hadoop/core-site.xml");
conf.addResource("classpath:/hadoop/hdfs-site.xml");
conf.addResource("classpath:/hadoop/mapred-site.xml");
return conf;
}
public void mkdirs(String folder) throws IOException {
Path path = new Path(folder);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
if (!fs.exists(path)) {
fs.mkdirs(path);
System.out.println("Create: " + folder);
}
fs.close();
}
public void rmr(String folder) throws IOException {
Path path = new Path(folder);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
fs.deleteOnExit(path);
System.out.println("Delete: " + folder);
fs.close();
}
public void rename(String src, String dst) throws IOException {
Path name1 = new Path(src);
Path name2 = new Path(dst);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
fs.rename(name1, name2);
System.out.println("Rename: from " + src + " to " + dst);
fs.close();
}
public void ls(String folder) throws IOException {
Path path = new Path(folder);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
FileStatus[] list = fs.listStatus(path);
System.out.println("ls: " + folder);
System.out.println("==========================================================");
for (FileStatus f : list) {
System.out.printf("name: %s, folder: %s, size: %d\n", f.getPath(), f.isDir(), f.getLen());
}
System.out.println("==========================================================");
fs.close();
}
public void createFile(String file, String content) throws IOException {
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
byte[] buff = content.getBytes();
FSDataOutputStream os = null;
try {
os = fs.create(new Path(file));
os.write(buff, 0, buff.length);
System.out.println("Create: " + file);
} finally {
if (os != null)
os.close();
}
fs.close();
}
public void copyFile(String local, String remote) throws IOException {
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
fs.copyFromLocalFile(new Path(local), new Path(remote));
System.out.println("copy from: " + local + " to " + remote);
fs.close();
}
public void download(String remote, String local) throws IOException {
Path path = new Path(remote);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
fs.copyToLocalFile(path, new Path(local));
System.out.println("download: from" + remote + " to " + local);
fs.close();
}
public String cat(String remoteFile) throws IOException {
Path path = new Path(remoteFile);
FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);
FSDataInputStream fsdis = null;
System.out.println("cat: " + remoteFile);
OutputStream baos = new ByteArrayOutputStream();
String str = null;
try {
fsdis = fs.open(path);
IOUtils.copyBytes(fsdis, baos, 4096, false);
str = baos.toString();
} finally {
IOUtils.closeStream(fsdis);
fs.close();
}
System.out.println(str);
return str;
}
public void location() throws IOException {
// String folder = hdfsPath + "create/";
// String file = "t2.txt";
// FileSystem fs = FileSystem.get(URI.create(hdfsPath), new
// Configuration());
// FileStatus f = fs.getFileStatus(new Path(folder + file));
// BlockLocation[] list = fs.getFileBlockLocations(f, 0, f.getLen());
//
// System.out.println("File Location: " + folder + file);
// for (BlockLocation bl : list) {
// String[] hosts = bl.getHosts();
// for (String host : hosts) {
// System.out.println("host:" + host);
// }
// }
// fs.close();
}
}