java basics for hadoop

Java basics --- reflection mechanism, java basics ---1. Is java a Dynamic Language? Generally speaking, dynamic language means that the program structure or variable type can be changed while the program is running. From this point of view,

Operation of the Java interface on the Hadoop cluster Start with a configured Hadoop cluster This is what I implemented in the test class of the project that I built in the SSM framework. One, under Windows configuration environment variable download file and unzip to C drive or other directory.Link: http://pan.baidu.com/s/1jHHPElg Password: AUF

;ImportOrg.apache.hadoop.mapreduce.lib.output.FileOutputFormat; Public classMain { Public Static voidMain (string[] args)throwsException {String input= "Hdfs://test1:8020/test/**/test/zhangwenchao/java/wordcount/intput"; String Output= "Hdfs://test1:8020/test/**/test/zhangwenchao/java/wordcount/output"; Configuration conf=NewConfiguration (); Job Job=NewJob (conf); Job.setjobname ("Test4"); Job.setjarbyclas

carefully to find the jar packages that are needed in the Hadoop-2.6.0/share/hadoop sub-directories below:root@fd-ubuntu:/usr/hadoop/hadoop-2.6.0/share/hadoop# lscommon hdfs httpfs kms mapreduce tools yarnSo we can first add a recursive search environment variable to

); Desc.put ("ByteSize", 0l); NewThread (NewRunnable () {@Override Public voidrun () {//TODO auto-generated Method Stub while(true) { Try{Thread.Sleep (500); System.out.printf ("Maxl:%d\tcurrent:%d\tsurplus:%d\tprogressbar:%s\n", Desc.get ("ByteSize"), Desc.get ("current"), Desc.get (" ByteSize ")-desc.get (" current "), Df.format ((Desc.get (" current ") +0.0)/desc.get (" ByteSize "))); } Catch(interruptedexception e) {//TODO auto-generated Catch blockE.prints

Shell script -- run hadoop on linux Terminal -- the java file is saved as test. sh. the java file is wc. java, [Note: it will be packaged into 1. jar, the main function class is wc, the input directory address on hdfs is input, and the output directory address on hdfs is output. [note: The input directory and output di

Shell script -- run hadoop on linux terminal -- the java file is saved as test. sh. the java file is wc. java, [Note: It will be packaged into 1. jar, the main function class is wc, the input directory address on hdfs is input, and the output directory address on hdfs is output [Note: the input directory and output dir

and Sqoopwriting a program to put data into HDFs is better than using existing tools. Because there are now very mature tools to do this, and have covered most of the demand. Flume is a tool for Apache's massive data movement. One of the typical applications isdeploy the flume on a Web server machine,collect the logs on the Web server and import them into HDFs. It also supports various log writes. Sqoop is also an Apache tool used to bulk import large amounts of structured data into HDFS, such

the pain.In order to learn C + +, I borrowed from the library a good tutorial "21 days to learn C + +", do not be fooled by this title, the original author of the book is a foreigner, foreigners books are translated, and then published generally good. And actually in order to learn C + +, I paid almost 5, 6 21 days.In the early days of studying this book, it was really scratching, restless and uncomfortable. But with the depth, with the solution of one problem after another, learned the variabl

Java basics-GUI programming (2), java basics gui Programming I. event listening Mechanism -- Event Source: the graphical components in the awt or swing package, that is, the components in which the event occurs. -- Event: An operation performed by the Event user on the component. -- Listener: Listener is responsible fo

://jdk2.rar"); Ioutils.copybytes (inch, Output,4096,true); }The Testupload method is to upload the local "c://jdk.rar" file to the HDFs system root directory and name it uploadjdk.The Testdownload method is to download the "eclipse-sdk-4.3.1-linux-gtk-x86_64.tar.gz" in the root directory of the HDFS systemto the C drive of this address and name it "Jdk2.rar"It is worth noting that:hdfs://192.168.1.7:9000"Address is the second article" Ubuntu Hadoop 2.

In Javase's basic course, flow is a very important concept, and has been widely used in Hadoop, this blog will be focused on the flow of in-depth detailed.A The related concepts of javase midstream1, the definition of flow① in Java, if a class is dedicated to data transfer, this class is called a stream② flow is one of the channels used for data transmission since the grafting between programs and devices,

This article describes the resolution process for job recalculation when submitting jobs in CentOS 6.5 to Hadoop 1.2.1 encountered Error:java heap space errors in the reduce phase. Workaround for Linux, Mac os X, and Windows operating systems.Environment: Mac OS X 10.9.5, IntelliJ idea 13.1.4, Hadoop 1.2.1Hadoop is placed in a virtual machine, and the host is connected via SSH, IDE and data files on the hos

instancesSo Java serialization is very powerful, the serialization of the information is very detailed, but the serialization of memory.2.Hadoop serializationCompared to the JDK relatively concise, in the urgent mass of information transmission is mainly by these serialized byte building to pass, so faster speed, smaller capacity.Features of Hadoop serialization

When you start the daemon thread: Sbin/start-dfs. SHThe following error alert appears:WARN util. nativecodeloader:unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicableWorkaround:Download the corresponding version below the URL (I'm using hadoop-2.5.2)Http://dl.bintray.com/sequenceiq/sequenceiq-binAfter downloading,

Path (path); try {FileSystem FileSystem = Getfilesystem (); if (Filesystem.isfile (strpath)) {result = Filesystem.delete (strpath); } else{throw new NullPointerException ("Logical exception: Error deleting file attribute, failed to delete file, if delete folder should use RemoveDir (String path)"); }} catch (Exception e) {System.out.println ("exception:" + E.getmessage ()); } return result; /** * to a list of files or folders * @param path files or fo

Why does data analysis generally use java instead of hadoop, flume, and hive APIs to process related services? Why does data analysis generally use java instead of hadoop, flume, and hive APIs to process related services? Reply content: Why does data analysis generally use java