learn java hard way

= new SimpleDateFormat ("yyyy. Mm.dd HH:mm:ss "); Return Sdf.format (New Date ()); } static public String Getsimpleformattime () { SimpleDateFormat SDF = new SimpleDateFormat ("Yyyymmddhhmm", locale.us); Return Sdf.format (New Date ()); } } As long as you look carefully, a friend who wants to solve his own problem must see that this code, though simple, has already explained the conversion of date to string. SimpleDateFormat's bag is java.text. What about the conversion from string to date? To

, such as: SPRING,STRUTS2,HIBERNATE,SPRINGMVC, etc. These are basic knowledge that must be mastered by a primary development engineer.When you have completed the above, you naturally want to find out the operation mechanism of the JVM, to improve the efficiency of their code execution, to see the source code in the JDK to improve their programming ability, and so on is the natural thing. Do not write a few lines of code to study what source Ah, mechanism ah, efficiency ah, in fact, is out of the

need a brief understanding, or I just need to know a little about what problems this AOP can solve. If this new creature is not what I need, or the problem solved is not what I have encountered, why do I need to spend time researching it? In the next few days, I gave up further research on AOP. Only the concept and problems that can be solved are left in the brain. See it. In this way, I can save some time and invest more in my workflow drill. I tho

subclasses that do not support multiple inheritance in Java cannot enjoy the imperfections of members of more than one parent class.3) PolymorphismPolymorphism is another important feature of object-oriented programming. Polymorphism is a phenomenon that allows duplicate names in programs. The Java language contains method overloads and members covering two forms of polymorphism.Method overloading: In a cl

I started to learn Java for two weeks. Although I didn't watch Java every day, I should take a look at it the next day. After all, I have other courses. In the course of self-study, I found that Java is purely object-oriented and has many similarities with C ++. (before that, I have been familiar with object-oriented C

static final(17) Try to use HashMap and ArrayList, unless necessary, it is not recommended to use Hashtable and vectors, the latter due to the use of synchronization mechanism, resulting in performance overhead.This blog post is nearing the end. Finally, the optimization of Java code in Android development.In Android development, avoid using the internal get, set method as much as possible.In Android programming, calls to virtual methods incur a lot

chart. For example, the folders and file graphics displayed in the project Navigation view represent the related project and property views in another editing window. The eclipse perspective can display any view and edit window. All editor instances appear in an editor area and can be viewed through the folder view. A Workbench window can display any number of folder views. Each folder view can display one or more views.Learn a little every day and make a little progress every day. If you want

10 Mind maps take you to learn Java? ScriptHere are 10 JavaScript-related mind maps for the PO.　　Categorized as: 　JavaScript variables JavaScript operators JavaScript arrays JavaScript process statements JavaScript String functions JavaScript function Basics JavaScript Base DOM Operations 　DOM Document Object Model BOM Browser Object Model 　JavaScript Regular Exp

12. Error handling by exceptionThe basic idea of Java is that "poorly structured code cannot run."The purpose of exception handling in Java is to simplify the generation of large, reliable programs by using less than the current amount of code, and this way you can make yourself more confident: There are no unhandled errors in your program.1. Concept C and other

depicts the relationship between the thread and monitor, and the state transition diagram of the thread:As you can see, each monitor can be owned by only one thread at a time, and the thread is "Active thread", while the other threads are "waiting thread", waiting in the two queue "Entry set" and "Wait set" respectively. The state of the thread waiting in "Entry set" is "Waiting for monitor Entry", while the thread state waiting in "wait set" is "in Object.wait ()". Simply understood:"Entry set

Balancing, Nginx and Tomcat clustering, Use LoadRunner testing tools, optimization of performance memory tuning, code optimization and refactoring methods, and more.Of course, learning is inseparable from the process, to form their own programming thinking, when encountering problems, you can come up with solutions to deal with. Hope to share can help the needs of the pot friends. If you want to stand out from the many IT workers, you need to have advanced technology and learning to add value i

Learn the basics of Java password extensions Java password Extension (the Java Cryptography Extension), is an important part of JDK1.4, basically, he is composed of some packages, these packages formed a framework and implemented a number of encryption, key generation algorith

[]data = new char[6]; Public synchronized void push (char c) {if (index = = data.length) {try{this.wait (); }catch (Interruptedexception e) {}} this.notify (); Data[index] = c; index++; Public synchronized char pop () {if (index ==0) {try{this.wait (); }catch (Interruptedexception e) {}} this.notify (); index--; return Data[index]; } class Producer implements runnable{Syncstack stack; Public Producer (Syncstack s) {stack = s; public void Run () {for(int i=0; i The above is about

concept is the most important, after all, the program language is facing your brain thinking and computer, there is a clear thinking and open minded to learn, You will find that the program language is not so difficult to learn, the conversion platform is not so difficult to "cross." The education system takes the. Net, Java two big camp as the entry brick, this

Follow the examples to learn java multi-thread 7-object combination and release, java7- The purpose of learning thread security and synchronization is to implement reusable components or compile larger programs. Classes in java are object abstraction, so how to implement a thread security class is a technology we must know and use correctly. In the process of des

Java-related Learning notesRecent days did not update the blog, in fact, the main is to find work, so the blog update is relatively slow, I am a like to engage in software development, this time I again wayward a handful, I'm not looking for a salary. NET related industries, I decided to choose my favorite Java, all the fate of it, I finally wish to engage in the Java