HelloWorld of the HDFS API

1. Source Code

Import org.apache.hadoop.fs.fsurlstreamhandlerfactory;import org.apache.hadoop.io.ioutils;import  java.io.inputstream;import java.net.url;/** * example 3.1 */public class  URLCat {    static {         Url.seturlstreamhandlerfactory (New fsurlstreamhandlerfactory ());    }     public static void main (String[] args)  throws Exception {         InputStream in = null;         try {            in =  new url (Args[0]). OpenStream ();             ioutils.copybytes (In, system.out, 4096, false);         } finally {&nbsP;           ioutils.closestream (in);         }    }}

package cn.kissoft.hadoop.week04;import org.apache.hadoop.conf.configuration;import  Org.apache.hadoop.fs.filesystem;import org.apache.hadoop.fs.path;import org.apache.hadoop.io.ioutils ;import java.io.inputstream;import java.net.uri;/** * example 3.2 */public  Class homework1 {    public static void main (String[] args)  throws Exception {        String uri =  args[0];        configuration conf = new  Configuration ();         filesystem fs = filesystem.get ( Uri.create (URI),  conf);        inputstream in =  null;        try {             in = fs.open (New path (URI));             Ioutils.copybytes (In, system.out, 4096, false);         } finally {             Ioutils.closestream (in);         }    }}

2. How to run the. Class

Note: In this example, the Urlcat class is in the default package, and if there is a package, the class name should be preceded by a packet.

3. How the. Jar Runs