[Hbase learning notes] 1.Hbase Standalone Mode

I think the data is quite interesting this year. I plan to work hard in this direction This is mainly based on manjaro. It took a long time to install this system, and gradually felt that this distribution is more comfortable than Ubuntu. Install JDK In fact, the shell command is not important. It is mainly to install JDK, and then set JAVA_HOM ...

Posted on Sun, 15 Dec 2019 15:10:07 -0500 by KnottyAlder

java implements a simple thread pool

Pool is a very popular resource management mode, such as thread pool, connection pool and so on. For thread pool, some basic implementations of thread pool have been provided in java class library, In normal applications, what we use in the class library is enough. But do you have the same question as me, how do threads in t ...

Posted on Sun, 15 Dec 2019 14:28:32 -0500 by Toneboy

Java compile time constant and run time constant

Compile time constant refers to the specific value that the program can determine at compile time. A non compile time constant is a constant whose value can only be determined by a program at run time, so it is also called a run time constant. In Java, compile time constant refers to the basic type or String type decorated with final keyword an ...

Posted on Sun, 15 Dec 2019 12:48:46 -0500 by rajns

Pit of several storage methods in JavaPairRDD method

1,ERROR Utils: Aborting task   java.io.IOException: key out of order: For after package Code first public static void main(String[] args) throws ClassNotFoundException { SparkConf sparkConf = new SparkConf().setAppName("SparkTest-MapFile").setMaster("local"); sparkConf.registerKryoClasses(new Class<?>[] { Class.forName("org.apach ...

Posted on Sun, 15 Dec 2019 11:32:26 -0500 by donald

Android Gradle 2.3.3 upgrade 3.0.1 small record

For various reasons, Android Gradle needs to be upgraded. When gradle > 3.0, Java 8 is supported by default. Each large version upgrade involves a lot of content, so you should be as careful as possible, but you should simply record the problems encountered in the upgrade process; Upgrade classpath 'com.android.tools.build:gradle:3.0.1' Afte ...

Posted on Sun, 15 Dec 2019 06:36:48 -0500 by Kinneh

RBAC rights management based on spring security security framework

rbac-security GitHub address This is a privilege management module based on simple RBAC model and Spring Security. I. Introduction to RBAC model RBAC is the abbreviation of Role-Based Access Control, which means Role-Based Access Control. Basic idea: all kinds of permissions for the system are not directly granted to specific users, but to es ...

Posted on Sun, 15 Dec 2019 05:53:48 -0500 by gwizz

[Java Concurrency] AQS Abstract Queue Synchronizer Source Parsing--Lock Acquisition Process

AbstractQueuedSynchronizer (AQS) must be taken out to learn more about java concurrency. AQS can be said to run through the entire JUC concurrent packages, such as ReentrantLock, CountDownLatch, CyclicBarrier, and so on.Next, the implementation principle of AQS is analyzed. Before you begin the analysis, you must first look at the CLH synchroni ...

Posted on Sun, 15 Dec 2019 04:52:27 -0500 by BigE

Java Multithreaded Foundation

brief introduction In the previous article Java Multithreading Foundation (1) We have mentioned some common methods of threading. In this article, we will look at the use of some of them and the differences between them to make better use of them in our work. wait method and notify method The wait method and notify method are defined in the Obj ...

Posted on Sun, 15 Dec 2019 04:12:13 -0500 by Nuggit

The evolution of ThreadLocal--TransmittableThreadLocal

In the previous article, we talked about InheritableThreadLocal, which addresses the problem that ThreadLocal cannot share context with parent and child threads.But we may have heard of Ali's open source product TransmittableThreadLocal, so what does it do?<!-- more --> Sharing in Thread Pool In multithreading, we rarely directly new a th ...

Posted on Sat, 14 Dec 2019 21:16:44 -0500 by mark123$

Best solution for web printing

Pain Points in web Printing There are many printing schemes for winform, which are easy to implement and very stunning; however, more and more systems are now on the web or even on the mobile side.There are also very many web printing schemes on the web, but there are many kinds of problems, such as js compatibility, stability and so on, which ...

Posted on Sat, 14 Dec 2019 21:15:17 -0500 by ow-phil