java basics for hadoop

locallyFileinputformat.setinputpaths (Job, "hdfs://master:9000/wcinput/"); Fileoutputformat.setoutputpath (Job, New Path ("hdfs://master:9000/wcoutput2/"));Note that this is to pull the HDFs file locally to run, if you observe the output, you will see the Jobid with the local wordAt the same time this operation is not required yarn (self-stop yarn service to do experiments)At the remote server executionConf.set ("Fs.defaultfs", "hdfs://master:9000/"); Conf.set ("Mapreduce.job.jar", "Target/wc.j

Java BASICS (12) IO input and output, java basics io Input and OutputI. IO Overview 1. IO concepts IO: I represents Input; O represents Output. In Java, IO is input and output based on a stream. AllSerializing data(SAVE) write to the output stream or read from the input stre

Java basics --- thread issues, java basics ---1: Inherit the Thread class. Why should we inherit the run method? Answer: Thread implements the Runnable interface, The run method is the Runnable method, and the method in the interfaceThe default value is public abstract. If the Thread class is inherited and the run meth

Java basics 6: java BasicsJava basics 61 and javadoc1.1 usage Usage: javadoc [options] [packagenames] [sourcefiles] [@ files] 1.2 instance 1.3 Note To be docized, it must be a public class) Ii. classpath A reference to the classpath variable Iii. Singleton Design Model Iv. inherit the benefits of in

Java basics-multithreading and java basics-Multithreading1. Purpose of introducing threads and processes The purpose of introducing processes in the OS is to enable more programs to execute concurrently, so as to improve the resource utilization and the amount of the system. The thread is introduced to reduce the time

Java BASICS (15th) Set (2), java basics set Here are some of the knowledge points and code I summarized in my previous class. Most of the notes I think are very good and classic, sincerely hope that these will help those who want to learn! It is inconvenient to upload code by module. There are also many things, and the

Java BASICS (16) Set (3) and java basics set Here are some of the knowledge points and code I summarized in my previous class. Most of the notes I think are very good and classic, sincerely hope that these will help those who want to learn! It is inconvenient to upload code by module. There are also many things, and th

Java BASICS (20) IO streams (3) and java basics io streams Here are some of the knowledge points and code I summarized in my previous class. Most of the notes I think are very good and classic, sincerely hope that these will help those who want to learn! It is inconvenient to upload code by module. There are also many

Java basics-GUI programming (1), java basics gui Programming I. Definition The full name of GUI is Graphical User Interface, that is, Graphical User Interface. JDK provides two packages, AWT and Swing, for GUI program design and development. 1. java. awt abstract Window Tool

Java BASICS (5): java Basics1. Object-oriented Object-oriented: a programming idea1, Class and Object ClassIt refers to describing a class of things, or as a classification. It can regard classes as templates for constructing objects. 　　ObjectIt refers to a specific individual (also called an instance-instance ). Create an object using new. If no object exists, a

Java basics 2. java Basics58. Basic concepts of threads, basic states of threads, and relations between StatesA thread refers to an execution unit that can execute program code during program execution. Each program has at least one thread, that is, the program itself.Java threads have four states: running, ready, suspended, and ended.59. Common JSP commandsIsErr

Java basics 3. java Basics58. Basic concepts of threads, basic states of threads, and relations between StatesA thread refers to an execution unit that can execute program code during program execution. Each program has at least one thread, that is, the program itself.Java threads have four states: running, ready, suspended, and ended.59. Common JSP commandsIsErr

This article describes the configuration method for using the HDFs Java API.1, first solve the dependence, pomDependency> groupId>Org.apache.hadoopgroupId> Artifactid>Hadoop-clientArtifactid> version>2.7.2version> Scope>ProvidedScope> Dependency>2, configuration files, storage HDFs cluster configuration information, basically from Core-site.xml and Hdfs-sit

Java basics 1 Environment configuration, java basics 1 1. Download JDK: http://www.oracle.com/technetwork/java/javase/downloads/index.html 2. Install JDK: Click Next to complete. Note: The default installation path is C: \ Program Files \

Java basics-> Use of verification codes, java basics-verification Codes A verification code is a public, fully automated program that distinguishes users from computers and people. It can prevent malicious password cracking, ticket flushing, and Forum bumping, effectively preventing a hacker from continuously logging o

Java basics-generic 1 and java Basics The use of generics can make the type name as a parameter in the class or interface definition, just like a common parameter, so that the defined type is more universal. Advantages of generics: Strict type check for compilation The java