thinking recursively with java

. A1 PackageP1;2 Import Staticjava.lang.system.*;3 4 Public classC {5 voidDemo () {6A A =NewA ();7 out.println (A.M1);8 out.println (a.m2);9 out.println (a.m3);Ten //out.println (A.M4); One A a.f1 (); A.f2 (); a.f3 (); - //a.f4 (); - the //the default class can be used within the same package -b b =NewB (); - } - + Public Static voidMain (string[] args) { - NewC (). Demo (); + } A}P1. C PackageP2;Importp1.*;Import Staticja

Final key is mainly used in three directions: Data For a base type, final makes the data constant, whereas for an object reference, final makes the reference constant and cannot be re-assigned to another object;Blank final Java allows you to define a blank final but you must complete the assignment in the domain definition or construction method to ensure that initialization is done before use. Method Lock the method to prevent

, there are public class Widget{} some caveats when using keywords to restrict access: Each compilation unit (file) can have only one public class. Each compilation unit has a single common interface, which is decorated with public. A class that is decorated with public must have the same name as the compilation unit (file), including case. Note that the access rights of a class can neither be private(which makes it inaccessible to any other class) and cannot be protected .

you do not actually get any objects. The storage space is allocated only when new is executed.However, if you want to assign a single storage space to a particular domain, do not create any objects, or you can invoke a method without creating an object, you need to use the keyword static. When you declare a thing static, it means that the domain live method is not associated with any object instance of the class that contains it. You can also access methods or data that are declared static to c

static variable, then more than one static variable, the memory overhead ... Especially on mobile phones.In summary, in the UI design to define a singleton mode, feel less reliable, unless there is no sub-component, or to avoid reporting to the child can only has a parent error, to constantly judge whether the children have a father, father, from the father to remove the child (because there is always a static father quoted you).Re-entry into the program, the different manifestations of

Object-oriented language, five basic features:1) All things are objects.2) programs are collections of objects that they communicate to each other by sending messages.3) Each object has its own storage that is composed of other objects.4) Each object has its type. That is, each object is an instance of a class (class), which is a synonym for a type5) All objects of a particular type can receive the same message. (Round is a type of geometry, Audi is a type of car) This alternative is one of the

+ "bureau"); //show people and computers each time the battle for(inti = 0; I ) {System.out.println ("You first" + (i + 1) + "bureau out of:" + Great (list1.get (i)) + "Computer out of:" +Great (List2.get (i))); } } } } //used to show the race process PublicString Great (intnum) { Switch(num) { Case1: returnScissors; Case2: returnStone; Case3: returnCloth; default: return NULL; } }}Test class: Pa

= Executors.newcachedthreadpool ();PrivateCyclicbarrier barrier; Public horserace(intNhorse,Final intPause) {//Construct a Cyclicbarrier object when you need to pass in a Runnable object when the count value is reduced to 0 //Execute, which is passed in the form of an anonymous inner class. Here this Runnable object is responsible for printing //out of the situation when all horses are moved once each time. Barrier =NewCyclicbarrier (Nhorse,NewRunnable () { Public void Run() {

(IOException e) {//at this time logging system is not yet available, recorded in servlet log Loglog ( "Could not open log4j configuration file" + Log4jconfigurationurl.toexternalform (), E) ; }} //can now start playing log. Resourceloader.setloggerready (true);} 4, two tool classes Arrays and collections 1.Arrays, this class contains various methods for manipulating arrays, such as sorting and searching. 2.Collections, provides a static method (Synchronous collection class method) that o

PackageCn.skyfffire;/** * * @authorSkyffire **/classTree {intheight; Tree () {PRT ("No parameter Construction"); } Tree (inti) {prt ("Create class tree using integer parameter" +i); Height=i; } Tree (String s) {prt (s); } voidinfo () {PRT ("Tree Value:" +height); } Static voidprt (String s) {System.out.println (s); }} Public classTest { Public Static voidMain (string[] args) {Tree atree=NewTree ("HHH"); Tree BTree=NewTree (1); Atree.info (); Btree.info (); }}Builder--

Random rand = new random (+); map　　Application of thinking in Java Learning notes map

-Sorteddirlist SDL =NewSorteddirlist ("c:\\",NULL, 1); the the sdl.print (); the } the } - the ///:~I use my own C packing directory as an example, the result of ascending sort is:$Recycle. BinBootnxtDocuments and SettingsOnedrivetempPerfLogsProgram FilesProgram Files (x86)ProgramDataQmdownloadRecoverySymcacheSystem Volume InformationUsersWindowsBootmgrPagefile.sysSwapfile.sysThe result of descending sort is:Swapfile.sysPagefile.sysBootmgrWindowsUsersSystem Volume InformationSymca

I. Where the object is saved Register (CPU) Stack (variable) Heap (object) Static domain (statics) Chang (String) Non-memory Zone pool Two. Basic data typesInteger byte short int long 8 16 32 64Float type float Double 32 64Character Char-UnicodeBoolean Type Boolean 1Three. Static belongs to a class call that does not belong to an object (many in a generic tool class)Thinking in Java (

Q: What is Object-oriented? What is the difference from a process-oriented one?A: Object-oriented: The problem-oriented space, based on the abstraction of the problem;Process oriented: The solution space, based on the computer structure to abstract;Five basic features of OOP:1) All things are objects.ExplainYou can extract any conceptualization artifacts that you want to solve for a problem and represent them as objects in your program.2) programs are collections of objects that they communicate

Interface list in the inherited interface collection, interface collection there is a size () method, in the interface list and the size () method, what is the point? (cover a lot of ways, see)Public interface List1. Both the parent interface and the sub-interface are abstract (not implemented), and the subclass does not change the method of the parent class, which does not make sense at the functional level. 2. The subclass method cannot narrow the access rights of the overridden methods, but t

Class.forName ("Test. TestClass "). The Newinstance () method requires the class test. TestClass must have an argument-free constructor, or an error will be found.Class.forName (test. TestClass) will be class test. The TestClass is loaded into the JVM and the initialization work is done, and the static methods in the class execute.Class C = class.forname (test. TestClass); The class returned by the Class.forName method has some common methods for returning class information, as follows:　　"

1. Abstract classes and abstract methods　　classes that contain abstract methods are called abstract classes. If a class contains one or more abstract methods, the class must be qualified as abstract. (otherwise, the compiler will make an error.) )It is useful to create abstract classes and abstract methods, because they can make classes more abstract and tell users and compilers how they intend to use them .Abstract classes are also useful refactoring tools because they make it easy to move publ

The so-called recursion, is oneself indirectly or directly to oneself.Three conditions to be aware of recursion:1. Boundary conditions2, recursive forward paragraph3. Recursive return segmentRecursive progression when boundary conditions are not metWhen the boundary condition is met, the recursive returnHere's a small example:public class Demo{public static void Main (String args[]){ToBin (6);}public static void toBin (int num){if (num>0){ToBin (NUM/2);System.out.println (num%2);}}}The first ste

actually a misunderstanding of system layering.4. The core design of the system is to classify the entities in the system into domain models. Based on this, the DAO layer of data is designed and exposed to the service layer, and the implementation of the service layer depends on the domain activity.5. The scope of responsibility of each interface is clear and bounded.File name:Action (Presentation layer)Domain (Domain level)Service (services Tier)Persistence (persistent layer, DAO layer)Util (s

"Toast" + ID + ":" + Status;}} /** * Toast Queue * * @author Lenovo * */class Toastqueue extends linkedblockingqueuePackage Org.rui.thread.block2;import Java.io.ioexception;import Java.io.pipedreader;import java.io.PipedWriter; Import Java.util.random;import Java.util.concurrent.executorservice;import Java.util.concurrent.executors;import java.util.concurrent.timeunit;/** * tasks using pipelines for input, output * * @author Lenovo * */class Sender implements Runnable {private Rand Om rand = ne