java读取HDFS的数据

通过JAVA直接读取HDFS中的时候，一定会用到FSDataInputStream类，通过FSDataInputStream以流的形式从HDFS读数据代码如下：

import java.io.IOException;import java.net.URI;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.FSDataInputStream;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.Path;public class FileReadFromHdfs {public static void main(String[] args) {try {String dsf = "hdfs://hadoop1:9000/tmp/wordcount/kkk.txt";Configuration conf = new Configuration();FileSystem fs = FileSystem.get(URI.create(dsf),conf);FSDataInputStream hdfsInStream = fs.open(new Path(dsf));byte[] ioBuffer = new byte[1024];int readLen = hdfsInStream.read(ioBuffer);while(readLen!=-1){System.out.write(ioBuffer, 0, readLen);readLen = hdfsInStream.read(ioBuffer);}hdfsInStream.close();fs.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}