放一個hello的文件到Hadoop 文件系統 根目錄：
[root@hadoop local]# touch hello
[root@hadoop local]# vi hello
[root@hadoop local]# hadoop fs -put hello /
代碼：
package hadoop.jack.javacallhadoop; import java.io.InputStream; import java.net.URL; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FsUrlStreamHandlerFactory; import org.apache.hadoop.io.IOUtils; public class App1 { public static String HDFS_PATH="hdfs://hadoop:9000/hello"; /** * @param args */ public static void main(String[] args) throws Exception{ URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory()); final URL url =new URL(HDFS_PATH); InputStream in = url.openStream(); IOUtils.copyBytes(in, System.out, new Configuration()); } } |