文章列表
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock ...
Spark introduction, interview question, quiz
https://data-flair.training/blogs/apache-spark-rdd-vs-dataframe-vs-dataset/
Strong References
Weak References
Soft References
Phantom References
https://www.geeksforgeeks.org/types-references-java/
正则表达式
- 博客分类：
- regular expression
https://zh.wikipedia.org/wiki/%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F#PCRE%E8%A1%A8%E8%BE%BE%E5%BC%8F%E5%85%A8%E9%9B%86
JProfiler入门教程
- 博客分类：
- JProfiler
https://www.cnblogs.com/zhangyaxiao/p/6678385.html
Java Garbage Collection
- 博客分类：
- GC
Java Garbage Collection Basics
Java Technology and the JVM
Describing Garbage Collection
The Generational Garbage Collection Process
Performing Your Own Observations
Java Garbage Collectors
https://www.oracle.com/webfolder/technetwork/tutorials/obe/java/gc01/index.html
Algorithms
- 博客分类：
- Algorithms
Algorithms implemented by Java
Binary Search
https://github.com/KellyLin1115/the-practice-of-programming/blob/master/src/chapter2/item1/BinarySearch.java
Quick Sort
https://github.com/KellyLin1115/the-practice-of-programming/blob/master/src/chapter2/item2/QuickSort.java
Quick 3 Way Sort
Arrays wit ...
Java language
- 博客分类：
- Java
1. Bit shift
>> (Signed right shift) : If the number is negative, then 1 is used as a filler and if the number is positive, then 0 is used as a filler.
>>> (Unsigned right shift) : It always fills 0 irrespective of the sign of the number.
<< (Left shift) : It always fills 0.
2 ...
1. mvn clean compile，mvn clean test，mvn clean package 和 mvn clean install:
执行test之前是会先执行compile的，执行package之前是会先执行test的，install之前会执行package。
2.scope的分类
compile：默认值 他表示被依赖项目需要参与当前项目的编译，还有后续的测试，运行周期也参与其中，是一个比较强的依赖。打包的时候通常需要包含进去
test：依赖项目仅仅参与测试相关的工作，包括测试代码的编译和执行，不会被打包，例如：junit
runtime：表示被依赖项目无需参与项目的编译，不 ...
在编写代码的时候直接输入psv就会看到一个psvm的提示，此时点击tab键一个main方法就写好了。
psvm 也就是public static void main的首字母。
sout--> System.out.println();
在方法体内键入for会有一个fori的提示，选中然后tab键，就会自动创建一个for循环。
Iteration
The comma operator
Comma operator (not the comma separator, which is used to separate definitions and method arguments) has only one use in Java: in the control expression of a for loop. In both the initialization and step portions of the control expression, you can have a number of stateme ...
Guaranteed initialization with the constructor
Note that the coding style of making the first letter of all methods lowercase does not apply to constructors, since the name of the constructor must match the name of the class exactly.
The constructor is an unusual type of method because it has no retu ...
Mathematical operators
Integer division truncates, rather than rounds, the result.
If you create a Random object with no arguments, Java uses the current time as a seed for the random number generator, and will thus produce different output for each execution of the program.
Logical operators
Each ...
You must create all the objects
Where storage lives
There are five different places to store data：
1. Registers.This is the fastest storage because it exists in a place different from that of other storage: inside the processor. However, the number of registers is severely limited, so registers are a ...
The progress of abstraction
Assembly language is a small abstraction of the underlying machines.
Many so-called “imperative” languages that followed (such as FORTRAN, BASIC, and C) were abstractions of assembly language. Their primary abstraction still requires you to think in terms of the structur ...