hdfs 例子
package hadoop; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.BlockLocation; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.LocatedFileStatus; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.RemoteIterator; public class HdfsClient { public static void main(String[] args) throws IOException, InterruptedException, URISyntaxException { FileSystem fs = null; Configuration conf = new Configuration(); fs = FileSystem.get(new URI("hdfs://192.168.1.231:9000"), conf, "root"); //上传 //fs.copyFromLocalFile( new Path("F:/新建文本文档.txt") , new Path("/") ); //下载 fs.copyToLocalFile( new Path( "/新建文本文档.txt" ), new Path( "F:/aaa" )); // 创建目录 fs.mkdirs(new Path("/a1/b1/c1")); // 删除文件夹 ,如果是非空文件夹,参数2必须给值true fs.delete(new Path("/aaa"), true); // 重命名文件或文件夹 fs.rename(new Path("/a1"), new Path("/a2")); RemoteIterator<LocatedFileStatus> listFiles = fs.listFiles(new Path("/"), true); while (listFiles.hasNext()) { LocatedFileStatus fileStatus = listFiles.next(); System.out.println(fileStatus.getPath().getName()); System.out.println(fileStatus.getBlockSize()); System.out.println(fileStatus.getPermission()); System.out.println(fileStatus.getLen()); BlockLocation[] blockLocations = fileStatus.getBlockLocations(); for (BlockLocation bl : blockLocations) { System.out.println("block-length:" + bl.getLength() + "--" + "block-offset:" + bl.getOffset()); String[] hosts = bl.getHosts(); for (String host : hosts) { System.out.println(host); } } System.out.println("--------------分割线--------------"); } FileStatus[] listStatus = fs.listStatus(new Path("/")); String flag = "d-- "; for (FileStatus fstatus : listStatus) { if (fstatus.isFile()) flag = "f-- "; System.out.println(flag + fstatus.getPath().getName()); } fs.close(); } }
依赖:
<groupId>org.apache.hadoop</groupId> <artifactId>hadoop-client</artifactId> <version>2.8.5</version> </dependency>
能耍的时候就一定要耍,不能耍的时候一定要学。
天道酬勤,贵在坚持
posted on 2018-09-29 17:21 zhangyukun 阅读(182) 评论(0) 编辑 收藏 举报