Java API操作HDFS

Java API操作HDFS

• 在hdfs上创建目录

public class TestMkdir {

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

         Configuration conf = new Configuration();

         FileSystem fs = FileSystem.get(new URI("hdfs://ip:9000") ,conf);

         fs.mkdirs(new Path("/demo1"));

         fs.close();

}

}

• 上传压缩包到/demo目录下

public class TestPut {

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

         Configuration configuration = new Configuration();

         FileSystem fs = FileSystem.get(new URI("hdfs://ip:9000"),configuration);

         fs.copyFromLocalFile(new Path("文件路径（eclipse所在的文件系统）"),new Path("/demo1"));

         fs.close();

}

}

• 从hdfs上下载文件到本地/home目录下

public class TestGet {

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

         Configuration conf = new Configuration();

         FileSystem fs = FileSystem.get(new URI("hdfs://ip:9000"),conf);

         fs.copyToLocalFile(new Path("文件路径（eclipse所在的文件系统）"), new Path("/home"));

         fs.close();

}

}

• 删除hdfs上的文件

public class TestDelete {

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

         Configuration conf = new Configuration();

         FileSystem fs = FileSystem.get(new URI("hdfs://ip:9000"),conf);

         fs.delete(new Path("/demo1"), true);

         fs.close();

}

}

• 查询hdfs上/demo目录下的文件

public class Testls {

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

         Configuration conf = new Configuration();

         FileSystem fs = FileSystem.get(new URI("hdfs://if:9000"),conf);

         FileStatus[] fileStatus = fs.listStatus(new Path("/"));

         for(FileStatus f : fileStatus){

                  Path path = f.getPath();

                  String str = path.getName();

                  System.out.println(str);

         }

}

}