Object Relational Mapping (ORM) is a technology to solve the mismatch between object-oriented and relational database. In short, ORM automatically persists objects in programs to relational databases by using metadata that describes the mapping between objects and databases.
When you develop an application (without O ...
Posted on Sat, 14 Sep 2019 06:52:58 -0700 by batman
1. Overview of MapReduce
Hadoop MapReduce is a distributed computing framework for writing batch applications.Written programs can be submitted to the Hadoop cluster for parallel processing of large datasets.
The MapReduce job splits the input dataset into separate blocks, which are processed by the map in parallel, and the framework sorts the ...
Posted on Fri, 13 Sep 2019 09:21:27 -0700 by tharagleb
Source code analysis of arraylist
1. Introduction to arrays
Arrays are very basic structures in data structures. Many programming languages have built-in arrays, which are similar to linearity in data structures.
When an array is created in java, a contiguous memory is partitioned out of memory, and then data is stored sequentially in this c ...
Posted on Thu, 12 Sep 2019 07:43:21 -0700 by koen
The last article has got through the serial port acquisition of one of the data sources. This time we want to talk about network acquisition. At present, there are three kinds of network communication, TCP/UDP/HTTP. Among them, TCP communication includes two kinds of client server. Tcp communication only uses multiple handshake mecha ...
Posted on Wed, 11 Sep 2019 18:51:33 -0700 by sps
1. Description of the problem
Today, when I was working on a project, I encountered dependency configured in the pom.xml file. Maven import/reimport could not be imported at all, as shown below:
idea opens maven tools windows and finds profiles only selected jdk1.8, xxResporsity,maven reimport, problem solving
3. Summarize p ...
Posted on Wed, 11 Sep 2019 16:55:02 -0700 by superdan_35
Introduction to ReentrantLock
Fundamental knowledge paving
Thread Holder Properties
Queue usage in ReentrantLock
Fair lock() method
Vernacular principles (interview dictation)
Summary of knowledge points
Summary of Life Track of FIFO Chain List
Posted on Wed, 11 Sep 2019 10:19:54 -0700 by mxicoders
Aspect Oriented Programming: Aspect Oriented Programming
AOP is to extract the duplicate code of our program. When it needs to be executed, we use dynamic proxy technology to enhance our existing methods without modifying the sou ...
Posted on Wed, 11 Sep 2019 05:37:33 -0700 by ghadacr
What is the singleton pattern?
Singleton pattern: A class can only have one instance, providing a global access point.
Whenever possible, make sure that a class has only one instance, and that it is self-instantiated and provides this instance to t ...
Posted on Wed, 11 Sep 2019 05:11:25 -0700 by gl_itch
What is Flink relational API?
Although Flink already supports DataSet and DataStream API s, is there a better way to program without caring about specific API implementations? There is no need to understand the specific implementations of Java and Scala.
Flink provides three layered APIs. Each API offers a different trade-off between conci ...
Posted on Wed, 11 Sep 2019 02:54:21 -0700 by navtheace
Since I started learning python, I've started to summarize a collection of Python tips myself. Later, when I saw a cool piece of code in Stack Overflow or in some open source software, I was surprised: I could have done that! At that time, I would tr ...
Posted on Wed, 11 Sep 2019 01:05:55 -0700 by nivaspm