本文实例为大家分享了Java代码对HDFS进行增删改查操作的具体代码，供大家参考，具体内容如下

import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.net.URI;import org.apache.commons.compress.utils.IOUtils;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.BlockLocation;import org.apache.hadoop.fs.FSDataInputStream;import org.apache.hadoop.fs.FSDataOutputStream;import org.apache.hadoop.fs.FileStatus;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.Path;public class FileOpreation { public static void main(String[] args) throws IOException { //CreateFile(); //DeleteFile(); //CopyFileToHDFS(); //MkDirs(); //DelDirs(); ListDirectory(); DownLoad(); } public static void CreateFile() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration =new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); byte[] file_content_buff="hello hadoop world, test write file !\n".getBytes(); Path dfs = new Path("/home/test.txt"); FSDataOutputStream outputStream = fSystem.create(dfs); outputStream.write(file_content_buff.length); } public FileOpreation() { // TODO Auto-generated constructor stub }public static void DeleteFile() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration =new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); Path deletf = new Path("/home/test.txt"); boolean delResult = fSystem.delete(deletf,true); System.out.println(delResult==true?"删除成功":"删除失败"); } public static void CopyFileToHDFS() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration =new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); Path src = new Path("E:\\SerializationTest\\APITest.txt"); Path dest_src = new Path("/home"); fSystem.copyFromLocalFile(src, dest_src); } public static void MkDirs() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration =new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); Path src = new Path("/Test"); fSystem.mkdirs(src); } public static void DelDirs() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration = new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); Path src = new Path("/Test"); fSystem.delete(src); } public static void ListDirectory() throws IOException { String uri = "hdfs://Alvis:9000"; Configuration configuration = new Configuration(); FileSystem fSystem = FileSystem.get(URI.create(uri), configuration); FileStatus[] fStatus = fSystem.listStatus(new Path("/output")); for(FileStatus status : fStatus) if (status.isFile()) { System.out.println("文件路径："+status.getPath().toString()); System.out.println("文件路径 getReplication："+status.getReplication()); System.out.println("文件路径 getBlockSize:"+status.getBlockSize()); BlockLocation[] blockLocations = fSystem.getFileBlockLocations(status, 0, status.getBlockSize()); for(BlockLocation location : blockLocations){ System.out.println("主机名："+location.getHosts()[0]); System.out.println("主机名："+location.getNames()[0]); } } else { System.out.println("directory:"+status.getPath().toString()); } } public static void DownLoad() throws IOException { Configuration configuration = new Configuration(); configuration.set("fs.defaultFS", "hdfs://Alvis:9000"); FileSystem fSystem =FileSystem.get(configuration); FSDataInputStream inputStream =fSystem.open( new Path("/input/wc.jar")); FileOutputStream outputStream = new FileOutputStream(new File("E:\\LearnLife\\DownLoad\\wc.jar")); IOUtils.copy(inputStream, outputStream); System.out.println("下载成功！"); }}

思想：

一、定义虚拟机接口

二、先拿到HDFS远程调用接口对象Configuration

三、定义分布式文件系统FileSystem对象获取对象

四、给定路径

五、用FileSystem对象调用操作

以上所述是小编给大家介绍的Java代码对HDFS进行增删改查操作详解整合，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！