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
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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服务器之家网站的支持！
原文链接：https://blog.csdn.net/qq_41395106/article/details/89036014
