java class extends

P1 are die, if the P1 object dies, then P2 will notHome, this is really unfair to P2, and if you create a home object for P1 and P2, you waste resources. So in this case,It is appropriate to use static internal analogies for ordinary internal classes.the difference between a static inner class and a normal inner class(1) Ordinary inner classes cannot declare static methods and variablesOrdinary inner class

The Inner class(inner Class) defines the classes in the class. (generally Java's argument)The Nested class(nested Class) is a static (static) inner class. (generally C + + parlance)Static inner

Reprinted from: http://chenzhou123520.iteye.com/blog/1597597The Java Virtual Machine specification does not have a mandatory constraint on when to start the class loading process, but for the initialization phase, the virtual machine specification strictly stipulates that there are only four cases where the class must be "initialized" (while the load, validate, p

the class loader to implement delegate class requests (for example, when the custom Class Loader cannot find a class using a special method ). In this case, the parent loader must be used as a parameter of the Java. Lang. classloader constructor: Public

Java _ abstract class, java Abstract class Abstract class1. syntax definitionThe abstract keyword is used before the abstract class.2. Application scenarios(1) In some cases, a parent class only knows how its subclass should conta

Java class loading sequence and Java class loading sequenceProblem Yesterday, someone asked me about the loading sequence of static methods, static code blocks, common code blocks, constructors, common methods, and static methods in a class? If there is something like inheri

its own properties and methods, but it cannot be instantiated because the parent class is instantiated, The parent class does not change the properties and methods in the anonymous class private String name = "AAA"; The {///anonymous class can have code blocks initialized. Cannot use static code blocks such as: Static

initialized. 2. The class is referenced through array definition, and class initialization is not triggered. 3. constants of the definition class. constants are stored in the constant pool of the call class during the compilation phase. In essence, they are not directly referenced to classes that define constants. The

public person (string aName, String aphonenumber, String anaddress) {name=aname; Phonenumber=aphonenumber; address=anaddress; }} public class Employee extends person {protected int employeenumber; Protected String workphonenumber; Public Employee () {///here implicitly calls the constructor method person () This (0, ""); The public Employee (int anumber, String aphonenumber) {///h

one StringBuilder class (1) Recognize StringBuilder class In Java, in addition to using the string class to store strings, you can also use the StringBuilder class or the StringBuffer class to store strings, where you need toIt i

[Java] class loading mechanism and java class loading mechanismParental Delegation Model: Three types of Loading Methods: BootStrap Loader, Extension Loader, and Application Loader. The three tubes have different scopes. None of them call the parent class and use the loader

The class object is generated in the following way:1. Class Name: The JVM will use the class loader to load the class into memory (provided that the class has not been loaded into memory) and does not do the initialization of the class