nur.aini.hadoop.TestHDFS.java Source code

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Here is the source code for nur.aini.hadoop.TestHDFS.java

Source

package nur.aini.hadoop;

/*
 * Program untuk melakukan testing apakah HDFS running, sekaligus contoh membuat dan menghapus file
 * @author : Nur Aini Rakhmawati
 * @since 1 Febuary 2011
 * @license : GPL
 */

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.Configuration;
import java.io.IOException;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;

public class TestHDFS {

    private static FileSystem hdfs = null;

    public static FileSystem getHdfs(String hadooppath) {
        if (hdfs == null) {
            try {
                Configuration conf = new Configuration();
                conf.addResource(new Path(hadooppath + "/conf/core-site.xml"));
                hdfs = FileSystem.get(conf);
            } catch (IOException ex) {
                System.err.print(ex.getMessage());
            }
        }
        return hdfs;
    }

    public static boolean exists(String path) {
        try {
            return hdfs.exists(new Path(path));
        } catch (IOException ex) {
            System.err.print(ex.getMessage());
        }
        return false;
    }

    /**
     * @param args[0] nama file
     * usage : TestHadoop namafile
     * requirement : hadoop-versi-core.jar
     */

    public static void main(String[] args) throws IOException {

        Path path = new Path("/user/" + System.getProperty("user.name") + '/' + args[1]);
        FileSystem HDFS = TestHDFS.getHdfs(args[0]);
        boolean hadoop = false;
        if (!TestHDFS.exists(path.toString())) {
            FSDataOutputStream dos = HDFS.create(path);
            dos.writeUTF("hadoop");
            dos.close();
        }

        if (TestHDFS.exists(path.toString())) {
            FSDataInputStream dis = HDFS.open(path);
            if (dis.readUTF().equalsIgnoreCase("hadoop"))
                hadoop = true;
            dis.close();
            HDFS.delete(path);
        }

        if (hadoop)
            System.out.print("OK");
        else
            System.out.print("ERR");

    }
}