Four data storage restoration methods involved in the restart process of Activity execution in Android
We know that when Configuration Change occurs (such as screen switching), the Activity will be restarted, that is, destroy and restart. Generally,
The middle part of this article has already introduced the meaning of virtual reality, that is, indirect acquisition, and examples show that TV channels allow people to indirectly obtain TV station frequencies. Therefore, in this sense, it is
Interface (interface): The interface is equivalent to class. All the methods in the interface are abstract methods. When you declare a method in an interface, you can use the abstract keyword or you can not use it. Typically, the abstract keyword
1. Static method:Member variables are divided into instance variables and static variables . Where an instance variable belongs to a specific instance, it must be instantiated before the class is actually present, and different objects have
Package com.fish.object;/*static (static, modifier) static modifier member variable: When static modifies a member variable, the data for that member variable is a shared data. How static member variables are accessed: mode one: Access by using
Document directory
Test Singleton Mode
Multi-thread considerations
Synchronization
A Method for Improving Performance
Double lock check
Implementation of an improved thread-safe Singleton Mode
Test Singleton Mode
Next, I use JUnit
Original article: http://blog.chinaunix.net/uid-26881496-id-3175819.html
Eclare_dynamic/implement_dynamic macroSome friends recently got stuck by several Macros in Chapter 3 when reading "let's get down to MFC". I remember these macros stuck when I
1. Review of member variables(1) Access to public member variables by object name(2) The member variables of each object are exclusive(3) member variables cannot be shared between objects2. static member variables(1) Static member variables in C +
Shared libraries supported by Linux (lib *. so) technology can not only effectively use system resources, but also bring great convenience and versatility to program design, so it is widely used by various levels of application systems. A
Final keywordConcept: final meaning is ultimately, immutable. Final is a modifier that can be used to modify a class , a member of a class , and a local variable . The construction method cannot be modified. Characteristics:A 1.final decorated class
The final conceptThe advent of inheritance increases the reusability of code and facilitates development. However, there are problems, some classes do not want to be inherited after the description, or some of the methods in the class function is
Basic Java Knowledge
Java is a high-level Internet-facing programming language introduced by Sun (Stanford University Network, Stanford University web Company) in 1995.
Java VM (Jvm:java virtual machine)
JRE (Java Runtime
Summary
The single case pattern is one of the simplest design patterns, but for Java developers, it has many drawbacks. In this month's column, David Geary explores the single case pattern and how to deal with these flaws in the face of
1. What is polymorphic?Multiple states of an objectLike what:Teacher a = old clock;Staff b= old clock;2. Polymorphic Manifestation(1)Father classnon-static member variable xStatic member variables ynon-static methods Eat, method Body Output Parent
1. When the virtual machine loads the Java class for the first time, it initializes the static initialization block, the static member variable, and the static method once.2. An instance of the class is created only when the new method is called3,
The member variables between the object and the object are independent of each other. To share data, you need to use static members and static methods .
As long as you declare static member variables in a class, you can allocate space for static
C ++ from scratch (11)
-- Knowledge about classes
Due to space limitations, this article is the next article in "C ++ from (11)", discussing polymorphism and other issues.
Virtual meanings
The middle part of this article has already introduced the
In C + +, a static member is an entire class rather than an object, and a static member variable stores only one copy for all objects to be shared. So it can be shared across all objects. Using static member variables to implement data sharing
It is important to understand the initialization order of each member of the class in Java so that you can have a global understanding of the class. Don't say too much, just look at the following example
Class father{ static{ System.
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