Reflection Mechanism ConceptLet's consider a scenario. If an object wants to view its own member properties while the program is running, what should we do?Consider another scenario. What if we want to obtain Class information of a class at runtime, such as its attributes, construction methods, and general methods before considering whether to create its objects?This requires reflection!
We. java files will become. class files after compilation. This is like a mirror, itself is.
What is IoC Inversion of Control (abbreviated as IoC) is a design principle in object-oriented programming, which can be used to reduce the degree of coupling between computer codes.One of the most common methods is called Dependency Injection (DI) and another is called Dependency Lookup.Through Inversion of Control, when an object is created, an external entity that regulates all objects in the system passes the references of the objects it depends on to it.
This article is a summary of mathematics and principles after learning.
pca readings from http://blog.jobbole.com/109015/
Principal Component Analysis (PCA)
Recently, I reviewed linear regression and explained the relationship between the two variables in the probability book. Are there any relationships between variables X and Y?Of course, in the book, x is a variable, y is a random variable, and y is assumed to obey the positive distribution.Then assuming that they are linearly related, their relationship must be y = ax+b.
here only introduces how to use, not the principle (want to know the principle of see here) 1. download Word2Vec(Java version address) 2. Prepare a corpus according to your own situation (sogou 2012 News Data) 3. Processing corpus. Take sogou 2012 News Data for Example; (1) firstly, HTML tags are processed and converted to utf8 encoding format: catnews _ tensite _ XML.dat | iconv-fgb18030-ttf-8-c | grep " < content >"
1. IOC, one of Spring2 cores 1. Introduction and Function of spring Spring is an open source design framework, which solves the loose coupling problem between business logic layer and other layers. Therefore, it applies interface-oriented programming ideas throughout the entire system.Spring is a lightweight Java development framework that emerged in 2003 and was created by Rod Johnson.Simply put, Spring is a layered Java Platform, Standard Edition/Ee Full-Stack (one-stop) lightweight
What is IoCIn the development of practical applications, it is necessary to avoid and reduce the dependency relationship between objects as much as possible, that is, to reduce the coupling degree.Ioc, on the other hand, solves various dependency relationships between general business objects and between business objects and persistence layer.In the implementation without Ioc, the objects are controlled by the internal code of the program.When an object needs to depend on another object, use new to create its dependent object to realize the connection between the two components, and this S implementation will cause the coupling between the components.
Beans managed by a container generally do not need to know the state of the container and directly use the Bean, but in some cases, it is necessary to directly operate the IOC container in the Bean. At this time, it is necessary to set the perception of the container in the Bean.Spring IOC also provides this function, which is accomplished through a specific aware interface.Aware interfaces include the following:
Concise Discussion on the Benefits of Spring IOC
IOC: Inversion of Control, it is not a technology, it is a design pattern.The so-called Inversion of Control is the relationship between programs controlled by the container, instead of being directly controlled by the programming code in the traditional implementation.To put it bluntly, the container controls the dependency between objects.
DI：Dependency Injection depends on injection, that is, the dependency relationship between components (objects) is determined by the container during runtime.
As we all know, the core features of Spring are IOC and AOP, IOC(Inversion of Control), or "Inversion of Control";AOP(Aspect-OrientedProgramming), or "Aspect Oriented Programming".The reference book Spring In Action shares my personal understanding of these two features.
IOC：IOC, another term is DI(Dependency Injection), which means dependency injection.It is not a technical realization, but a design idea.In any program project with practical development significance, we will use many classes to describe their unique functions and complete specific business logic through the mutual cooperation between classes.
KNN Algorithm Brief Introduction For a brief introduction of KNN algorithm, please refer to: K- Nearest Neighbor Algorithm (KNN)
Handwritten Number Recognition kNN algorithm is mainly applied to text classification and similar recommendation. This paper will describe an example of classification.
What is handwriting recognition?Please refer to Wikipedia Introduction: Handwriting Recognition
Data Download: Handwritten Recognition Data Data Description: Each handwritten digit has been processed into 32 * 32 binary text in advance, and the storage format is txt file.