我在 CentOS 6.6 上安装了一个基本的 hadoop 集群,并想编写一些基本程序(浏览文件系统、删除/添加文件等),但我什至连最基本的应用程序都无法正常工作.
I have installed a basic hadoop cluster on CentOS 6.6 and want to write a few basic programs (browse the filesystem, delete/add files, etc) but I'm struggling to get even the most basic app working.
在运行一些基本代码以将目录的内容列出到控制台时,我收到以下错误:
When running some basic code to list the contents of a directory to the console I get the following error:
Exception in thread "main" java.lang.NoSuchMethodError: org.apache.hadoop.ipc.RPC.getProxy(Ljava/lang/Class;JLjava/net/InetSocketAddress;Lorg/apache/hadoop/security/UserGroupInformation;Lorg/apache/hadoop/conf/Configuration;Ljavax/net/SocketFactory;ILorg/apache/hadoop/io/retry/RetryPolicy;Z)Lorg/apache/hadoop/ipc/VersionedProtocol;
at org.apache.hadoop.hdfs.DFSClient.createRPCNamenode(DFSClient.java:135)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:280)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:245)
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:100)
at mapreducetest.MapreduceTest.App.main(App.java:36)
我的 pom.xml 依赖项
My pom.xml dependencies
<dependencies>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.6.0</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
</dependencies>
代码:
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DistributedFileSystem;
public class App
{
public static void main( String[] args ) throws IOException, URISyntaxException
{
Configuration conf = new Configuration();
FileSystem fs = new DistributedFileSystem();
fs.initialize(new URI("hdfs://localhost:9000/"), conf);
for (FileStatus f :fs.listStatus(new Path("/")))
{
System.out.println(f.getPath().getName());
}
fs.close();
}
}
调用 fs.initialize() 后抛出错误.我真的不确定这里有什么问题.我是否缺少依赖项?他们是错误的版本吗?
The error is being thrown after calling fs.initialize(). I'm really not sure what the issue is here. Am I missing dependencies? Are they the wrong version?
我通过调用java -jar app.jar .... etc"来运行它我应该一直在使用hadoop jar app.jar".
I was running this by calling "java -jar app.jar .... etc" I should have been using "hadoop jar app.jar".
当我正确运行它时按预期工作.
Worked as intended when I ran it correctly.
这篇关于Hadoop 2.6.0 浏览文件系统 Java的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!