thinking recursively with java

Thinking about java objects, java objectsImmutable objects and Classes An object created by an immutable class is an immutable object. To make a class immutable, it must meet the following requirements: All data domains are private. No modifier Method If there is no accessor method, it returns a reference pointing to a variable data domain. See the following

1/** * Upward transformation * * * class Cycle { Public voidPlay () {System.out.println ("Cycle Play"); }} class unicycle extends Cycle{@Override Public voidPlay () {System.out.println ("Unicycle Play"); }} class Bicycle extends Cycle {@Override Public voidPlay () {System.out.println ("Bicycle Play"); }} class tricycle extends Cycle {@Override Public voidPlay () {System.out.println ("Tricycle Play"); }} Public class upcast { Public Static voidRide (Cycle c) {c.play (); } Public Static

typeIn Java SE5, the covariant return type is added, that is, the overridden method in the exported class can return some type of export of the return type of the base class method, some of which are bypassed, directly on the example:class Grain { public String toString() { return "Grain"; }}class Wheat extends Grain { public String toString() { return "Wheat"; }}class Mill { Grain process() { return new Grain();

I saw these two articles last week, but I haven't had enough time to translate them for reference. (This article is provided only to spread more information, and does not mean that I agree with his views and opinions. In addition, translation may be defective. You can refer to the original article to correct it. Thank you !) C # vs. Java: the opposite way of thinking (Part II) By Aaron hohnson, published i

Package Org.rui.thread.newc;import Java.util.arraylist;import Java.util.list;import java.util.random;import Java.util.concurrent.delayqueue;import Java.util.concurrent.delayed;import Java.util.concurrent.ExecutorService; Import Java.util.concurrent.executors;import java.util.concurrent.timeunit;/** * A variant of the deferred queue priority queue * * @author Lenovo * * * * Class Delayedtask implements Runnable, delayed{private static int counter = 0;private final int id = counter++;//ID from 0++

Org.rui.thread.deadlock;import Java.io.ioexception;import Java.util.concurrent.executorservice;import Java.util.concurrent.executors;import java.util.concurrent.timeunit;/** * Destroy the fourth article to prevent deadlock * @author Lenovo * */public class fixeddiningphilosophers {public static void main (string[] args) throws interruptedexception,ioexception {string[] arg = { "5", "5", "timeout"};int ponder = 5;if (Arg.length > 0) {ponder = Integer.parseint (Arg[0]);} int size = 5;if (Arg.len

Java uses ScheduledExecutor's greenhouse controller concurrently -- thinking in java 21.7.5 Package org. rui. thread. newc; import java. text. dateFormat; import java. text. simpleDateFormat; import java. util. arrayList; import

Both "Thinking in Java" and "Core Java" are classic books in Java. It's also a lot of the two books that have just come in contact with Java. Recently, the two books have been properly turned over again. Core Java is ideal for fi

Logical Thinking interview questions-java backend interview-,-java backend(-1) Preface I recently participated in an interview and was very interested in the pen questions. I will return to Baidu. Thinking about these questions reminds me of the association in modeling. I feel that it would be better to test logical

For Yesterday Java Learning Road (a)--thinking in Java static method of the class can not be accessed to create a non-static class, the internal class is modified to be static class, easy to operate. Now gives you a second, highly efficient way to add no deletions. You can copy and paste an inner class from a class you create into a class, and as an external clas

information storage pool, the software used to distribute the information, and the machine or cluster on which the information and software resides are collectively referred to as servers. Software that resides on the user's machine communicates with the server to obtain information, process information, and then display it on a user's machine called a client. From c/S to B/s, from client to browse, we can finally provide the service directly in the Web page without having to program it fo

TopicCreate a "Hello, World" program, compile it with Javac, and then run it in Java.Program1 Public class ex2_2 {2 Public Static void Main (string[] args) {3 System.out.println ("Hello, World"); 4 }5 }Compiling and runningWin+r Run cmdD: Change to D drive, CD (space) file path, arrival program Ex2_2.java DirectoryFormat of the Javac command: javac-d destdir srcfile (Destdir:java bytecode storage path Srcfile:.

Thinking about Java environment variable configuration, java environment variable I have been using environment variables before, but I have never thought about why? Java: JAVA_HOME = E: \ Study \ Java \ JDK7.0 Set in path % JAVA_HOME % lib; JAVA_HOME \ bin Do not

Today, a formal graduation, a company in Beijing also successfully concluded the internship. From school back to Beijing directly after the positive, although today in Saturday or go to the company around, has been trying to take a good look at the "Thinking in Java" (fourth edition), graduated, wholeheartedly into the work, naturally also have time, from today began to look at the side of this book, Make y

) {System.out.println ("Less than 3 parameters");return; The String result =""; for(String S:args) {result + = s +" "; } System.out.println ("Parameters:"+ result); }}/** * Output: * parameter: Caroline Wendy girl *///:~11//:allthecolorsoftherainbow/** * Coded style test * Created by C.l.wang on 15/7/6. * * Public class rainbowtest { Public Static void Main(string[] args) {Allthecoloroftherainbow ATC =NewAllthecoloroftherainbow (); Atc.changethehusofthecolor ( -); System.out.println ("Thehu

found the compiled (. Class) file through Classpath.Ways to gain access outside of the class:(1) Public, any can access.(2) Unrestricted access to the word, the package can be accessed.(3) Inheritance can access public and protected, within the package can access unlimited words, not outside the package.(4) Get, set method access private.The same directory does not give the package name, that is, in the default package, without qualifying words, giving the current class access rights.Class acce

; }}The example in this book is to use the command line to run arguments so that string "" is not empty. Other references to filtername within the class can be implemented using internal classes.The file class has a lot of operations, Google itself.File path = new File("hms.txt"); if(path.exists()){ System.out.println(path.getAbsolutePath()); }else{ path = new File("hms.txt"); System.out.println(path.getAbsolutePath()); }The first path = new

to call inside a constructor is those that is final in the base class. (This also applies to private methods, which is automatically final.)Convariant return typesJava SE5 adds convariant return types, which means, a overridden method in a derived class can return a type derived From the type returned by the Base-class methodDesigning with InheritanceIf you choose inheritance First when you ' re using a existing class to make a new class, things can become needlessly comp Licated.A better appro

Recently in the "tingking in Java" This book study, the second chapter exercises the topic of practice encountered a problem, No enclosing instance of type test1 is accessible. Must qualify the allocation with an enclosing instance of type test1 (e.g. X.new A () where X was an instance of Test1.The reason for the error is that the main method is static and cannot access the dynamic class you define, that is, you cannot create a reference to the class.

1 ImportJava.util.*;2 /**The first thinking in Java example program.3 * Displays a string and today ' s date.4 * @author122085 * @author http://www.cnblogs.com/liyifaner/6 */7 Public classHellodate {8 /**Entry point to Class application.9 * @paramargs Array of string argumentsTen * @throwsExceptions No Exceptions thrown One */ A Public Static voidMain (string[] args) { -System.out