以以下代码为例:
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.io.IOUtils;
public class ReadHdfsData {
public static void read_output(String name){
try{
FileSystem fs=FileSystem.get(new Configuration());
FSDataInputStream fsdata=fs.open(new Path(name));
IOUtils.copyBytes(fsdata, System.out, 4096, false);
IOUtils.closeStream(fsdata);
}catch(IOException e){
e.printStackTrace();
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
ReadHdfsData.read_output("hdfs://localhost/user/cj/output/part-r-00000");
}
}
一定要导入hadoop-2.7.1/share/hadoop/common/目录下hadoop-common-2.7.1.jar, 以及/usr/local/hadoop-2.7.1/share/hadoop/hdfs/目录下hadoop-hdfs-2.7.1.jar
core-site.xml 与hdfs-site.xml一定要放入java项目的bin 目录下