1. 创建HDFS Client 首先,我们需要创建HDFS Client对象,连接到HDFS: importorg.apache.hadoop.conf.Configuration;importorg.apache.hadoop.fs.FileSystem;importorg.apache.hadoop.fs.Path;importjava.io.IOException;importjava.net.URI;publicclassHDFSClient{publicstaticvoidmain(String[]args){Stringuri="hdfs://loc...
public class HDFSClient { public final static String HDFS_URI = "hdfs://hadoop113:9000"; public final static String HDFS_USER = "bd"; public final static String FILE_PRE = "/home/lxj/hadoop-data/"; public final static String HDFS_FILE_PRE = "/sanguo/shu/"; public static void main ...
packagecom.nijunyang.hadoop.hdfs;importorg.apache.hadoop.conf.Configuration;importorg.apache.hadoop.fs.*;importorg.junit.Before;importorg.junit.Test;importjava.net.URI;importjava.util.Arrays;/*** Description: * Created by nijunyang on 2019/12/25 20:26*/publicclassHDFSDemo { FileSystem fs; ...
packagecn.lshm.hdfs;importorg.apache.commons.io.IOUtils;importorg.apache.hadoop.conf.Configuration;importorg.apache.hadoop.fs.FSDataOutputStream;importorg.apache.hadoop.fs.FileSystem;importorg.apache.hadoop.fs.Path;importjava.io.FileInputStream;publicclassTestHDFSClient {publicstaticvoidmain(String[] args...
Java操作HDFS开发环境搭建 在之前我们已经介绍了如何在Linux上进行HDFS伪分布式环境的搭建,也介绍了hdfs中一些常用的命令。但是要如何在代码层面进行操作呢?这是本节将要介绍的内容: 1.首先使用IDEA创建一个maven工程: maven默认是不支持cdh的仓库的,需要在pom.xml中配置cdh的仓库,如下: 代码语言:javascript 代码运行次...
Java 代码中的配置从hdfs-site.xml中查找: <configuration> <property> <name>dfs.nameservices</name> <value>nameservice1</value> </property> <property> <name>dfs.client.failover.proxy.provider.nameservice1</name> <value>org.apache.hadoop.hdfs.server.namenod...
Java 代码中的配置从 hdfs-site.xml中查找: <configuration> <property> <name>dfs.nameservices</name> <value>nameservice1</value> </property> <property> <name>dfs.client.failover.proxy.provider.nameservice1</name> <value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider<...
使用Java API操作HDFS需要用到hadoop-common、hadoop-hdfs、hadoop-client三种依赖，同时为了进行单元测试，还要引入junit的测试包，具体代码如文件所示。文件 pom.xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns=`http://maven.apache.org/POM/4.0.0` xmlns:xsi=`"http://www.w3.org/...
*/ public class HDFSClient { @Test public void testMkdirs() throws IOException, InterruptedException, URISyntaxException { // 1 获取文件系统 Configuration configuration = new Configuration(); // 配置在集群上运行 FileSystem fs = FileSystem.get(URI.create("hdfs://hadoop001:9000"), configuration,...
<dependency><groupId>org.apache.hadoop</groupId><artifactId>hadoop-client</artifactId><version>2.8.1</version></dependency> 注:如需手动引入jar包,hdfs的jar包可以从Hadoop的安装包压缩文件中获取; 3.3.2 HDFS客户端对象 HDFS提供的客户端API中,最核心的类是FileSystem,它是一个抽象类,描述Hadoop所支持...