Question

一些人可以告诉我,我可以如何执行我的“热爱世界”。 java in apache haveoop

class Helloworld  
{  
  public static void main(String[] args)  
   {  
    Sytem.out.println("HelloWorld");  
    }  
 }

Am running a single node. Kindly tell me how can i run this piece of code or pls a send a link which is understandable for an absolute beginner.

Answer 1

单靠 had管的方式是由指挥部管理。

$HADOOP_HOME/bin/hadoop jar [your_jar_file]

也可以使用<条码>-jar<>/代码>强迫其从事当地工作。玩.和 de。

While I haven t tested with such a simple application, I think it should print the line and then be done. Don t hold me to that though. :-P

您可能需要具体说明<代码>main。 http://www.ohchr.org。我的法典就是这样。

我希望能够提供帮助。正如其他答复中提到的那样,如果不着手创造就业机会和地图,那么Hadoop就不会有收益。

Answer 2

就我所知,就你的情况而言,阿普切 had不相干。你们的问题是,“怎样才能在 j子里打造世界吗?

如果我的假设正确,则采取下列行动:

install JDK
compile your java code using command javac Helloworld.java. You have to run this from directory where your code is. The JAVA_HOME/bin should be in your path.
If #2 succeeded you should be able to see Helloworld.class at your working directory. Now run it by typing java Helloworld

Search for any java tutorial for beginners for details. good luck.

Answer 3

简短回答: 页: 1

Hadoop在一般意义上管理 j。它管理着“减少就业”计划,这项工作可以在 j中写成,但不必做。也许,你们应该首先阅读一些百分光文件。 http://hadoop.apache.org/mapreduce/docs/ 当前/mapred_tutorial.html” rel=“nofollow”>Map Reduce tutorial 。您也不妨看一看《Hadoop:确定指南》一书。

Hadoop是一个以批量为导向的大型数据处理系统。这实际上只适合这一问题空间的应用。如果这些问题不解决,那么Hadoop就是你重新寻找的问题。

Answer 4

由于这是一个古老的问题,许多人已经为这些问题提供了答案,我的回答是,像我这样的开端人,他们意外地跳入这一联系,而他们正在寻找一种办法,在Hadoop管理Hello World。

是的,Hadoop在JRV上运行。但是,仅仅因为你不需要Hadoop来管理这种简单应用。 Hadoop用于分配处理。这意味着假定你拥有大量数据集,而你的无辜计算机无法处理这一庞大的数据集。然后,你将做些什么,就是从能够共同完成这项任务的无辜(商品)电脑中获取帮助。

In the Hadoop environment, we are using a framework called Map-Reduce in order to do this kind of task. So obviously if you are not using the Map-Reduce framework in the Hadoop environment, it s like you are using a Space ship to climbing up to your rooftop instead of a ladder.

Even though this is the common hello world code for almost every programming language, this is not the hello world program for Hadoop. Here you have a program called Word-Count, which will count the number of occurrences in each word in a large text file or in an n number of files.

另外,还有三种模式可供你管理。

Local (Standalone) mode
Pseudo Distributed mode
Fully Distributed mode

My advice is to try to run the Word-Count program in Pseudo distributed mode as a beginner.

Answer 5

你们需要研究地图如何减少工程。你们可能想看一看一 examples的实例,以了解如何编写《地图减少方案》。

Answer 6

Standalone Operation By default, Hadoop is configured to run in a non-distributed mode, as a single Java process. This is useful for debugging.

The following example copies the unpacked conf directory to use as input and then finds and displays every match of the given regular expression. Output is written to the given output directory.

$ mkdir input 
$ cp conf/*.xml input 
$ bin/hadoop jar hadoop-*-examples.jar grep input output  dfs[a-z.]+  
$ cat output/*

see here: http://hadoop.apache.org/docs/r0.18.2/quickstart.html

友情链接