LitePal: An Open Source android Database Framework

When writing a project, we encounter the operation of database. The creation and use of database provided by Android feels a little complicated. We wonder if there is a better wheel-framework or tool class to use. We find litepal, an object-oriented ...

Posted by pandhandp on Mon, 16 Sep 2019 08:15:57 +0200

Lesson 92. What is polymorphism

What is polymorphism in java? There are two kinds of polymorphism: compile-time polymorphism: method overload; run-time polymorphism: JAVA runtime system decides which method to call according to the type of instance calling the method. (We usua ...

Posted by cruz610 on Mon, 16 Sep 2019 08:10:37 +0200

Goodbye Excel, I'm free to customize the form recommendation.

Many developers say that since Python/Pandas, Excel has not been used much, and it is very fast to process and visualize tables. Let me give you a few examples. 1. Delete duplicate and empty lines We use dict.fromkeys directly to convert the current data into a dictionary. The default value is None, because it is not used, so it doesn't matter ...

Posted by Minase on Mon, 16 Sep 2019 06:10:16 +0200

C++ const reference pointer

First, briefly recall the nature of a constant: int main() { const int buffSize = 512; buffsize = 512; //X buffSize is constant } At initialization: const int i = get_val(); //_Runtime Initialization const int j = 42; //_compile-time initialization const int k; //XK uninitialized When one object is used to in ...

Posted by kingman65 on Mon, 16 Sep 2019 06:02:54 +0200

spring Learning Records

** Basic Introduction to spring **1. What is Spring? Spring is a lightweight framework for IoC and AOP containers.A framework for providing basic services for Java applications to simplify the development of enterprise applications, which allows de ...

Posted by turtleman8605 on Mon, 16 Sep 2019 05:23:04 +0200

python implements the underlying data structure

The code involved in this article has been placed in my github--> link python implements basic data structures (1)python implements the underlying data structure (2) python implements basic data structures (3) python syntax is more concise, just ...

Posted by BRUUUCE on Mon, 16 Sep 2019 05:03:58 +0200

WEB Backend Service Day 21 - Project Day 1

WEB Backend Service Day 21 - Project Day 1 1. Build a project team development platform II. Basic usage of Docker and Quick Deployment Projects 2.1 Basic Description Mainstream Development Model: DevOps Development as Operations Maintenance Doc ...

Posted by Crazy-D on Mon, 16 Sep 2019 04:11:21 +0200

Java Description Design Patterns (11): Observer Patterns

This article source code: GitHub. Click here || GitEE. Click here I. Observer Model 1. Concept Description The observer pattern is the object's behavior pattern, also known as the Publish/Subscribe pattern. The observer pattern defines a one-to-many dependency that allows multiple observer objects to simultaneously listen to a subject object, ...

Posted by baze on Sun, 15 Sep 2019 17:49:02 +0200

Java Description Design Patterns (07): Adapter Patterns

This article source code: GitHub. Click here || GitEE. Click here Introduction of adapter mode 1. Basic concepts The adapter pattern transforms the interface of one class into another that the client expects, so that two classes that could not work together because of interface mismatch can work together. There are three types of adapter mod ...

Posted by gplevritis on Sun, 15 Sep 2019 16:13:36 +0200

Kafka Producer Source Code Analysis

Common terms of Kafka Broker: Kafka's server is an instance of Kafka. The Kafka cluster consists of one or more Brokers, which are responsible for receiving and processing client requests. Topic: Topic, a logical container for messages in Kafka. Each message published to Kafka has a corresponding logical container, which is often used to differ ...

Posted by packland on Sun, 15 Sep 2019 15:52:30 +0200