quickest way to learn java

To do web development, testing is a very time-consuming thing. So we should test it in a simpler and quicker way. Let's introduce a lightweight container--jetty today. J today said Etty is a maven plug-in Jetty-maven-plugin, with Maven to use very convenient, its configuration is very simple, below we see how it works!Under the so the configuration is complete, then right-click on the Pom.xml file, point to Run as, select Maven build, enter "Jetty:r

Nine, interfaceInterfaces and internal classes provide us with a more structured approach to separating interfaces from implementations.1. Abstract classes and abstract methodsAbstract classes are a kind of moderation between common classes and interfaces. Creating an abstract class is what you want to manipulate a series of classes through this generic interface. Java provides a mechanism called an abstract method , which is incomplete, with only de

Java has been learning for some time, and found that it is only to understand Java, but also outside the threshold.Sometimes it really feels like this is not an alien language, various methods of various kinds of excuses, always silly confused. Learned the knowledge after one weeks began to blur, sometimes sleep at midnight when still thinking, feel that they are almost schizophrenic, full brain in the chil

Generics are a new feature of Java SE 1.5, and the nature of generics is a parameterized type, meaning that the data type being manipulated is specified as a parameter. This type of parameter can be used in the creation of classes, interfaces, and methods, called generic classes, generic interfaces, and generic methods, respectively. the benefits of introducing generics into the Java language are simple and

Generics are a new feature of Java SE 1.5, and the nature of generics is a parameterized type, meaning that the data type being manipulated is specified as a parameter. This type of parameter can be used in the creation of classes, interfaces, and methods, called generic classes, generic interfaces, and generic methods, respectively. the benefits of introducing generics into the Java language are simple and

I saw this post in the Forum and spent half an hour writing a reply. I don't know which key I came across. I refreshed the interface. I don't think it's a pity, it is representative, so I will rewrite it here. There are still many similar questions. For example, is school learning useful? Why are there no frameworks or other courses in the school? Is Software Engineering useful? To answer this question, we must first consider what the school is doing? If the school's goal is to cultivate a

cache, distributed computing all understand, in fact, any one is just floating on the surface. At that time, the interviewer casually asked, he gave you see through.It is important to remember that as a program ape, there may be a lot of technology in contact on weekdays, but to make a technology your advantage, it must be your understanding of this technology is stronger than the vast majority of talent. So at this stage, you can not simply learn th

The purpose of this blog: ① summary of their own learning process, equivalent to study notes ② to share their own experience to everyone, learn from each other, communication, not commercialcontent inevitably appear problems, welcome to correct, exchange, discussion, you can leave a message, can also be contacted by the following ways. I Internet technology enthusiasts, Internet technology enthusiastsWeibo: Ivan is in 0221qq:951226918-----------------

;//dog is the target object with thread declaration speakpigpig;// pig is the target object Dog=newspeakdog (); //creates the target object Pig=newspeakpig (); // Create target object Speakdog=newthread (dog); //Create thread Its target object is Dogspeakpig=newthread (pig); //Create thread Its target object is Pigspeakdog.start (); //start thread Speakpig.start (); //start thread for (inti=1;i Threads can share the same memory units (including code and data) and use these shared units for d

Java.4: Save the object's reference to a lock-protected domain.Package Com.uskytec.ubc.foundation.queue;import java.util.hashmap;/** Route Cache * @author Gaoxu * */public class Routecache {private static Routecache instance = null;public synchronized static Routecache getinstance () {if (instance = = NULL) instance = new Routecache (); return instance;} Private final static hashmapWith these release strategies in hand, we can better write thread-saf

Take a few minutes to learn about final in Java . 1, the so-called final refers to the final modified properties, classes, methods can not be changed. 2,final the class, which means that the class cannot be inherited, For example, if Class B is final decorated, final class b{}, so Class A cannot inherit B. 3,final modifier, which means that the method cannot be overridden, 4,final modifies a variable to ind

of an anonymous class, and dynamically creating an instance of the anonymous class. The benefits of this writing are obvious, using interfaces to contract, and then actually using the business code when it is used. This makes the code much leaner, without the need to create a bunch of Java code units.However, if the class needs to be named and reused, it is less appropriate to use this approach, or there will be a lot of duplicated code. When looking

= 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

variables, use one of the following filter functions: Filter_var ()-Filters a single variable by a specified filter Filter_var_array ()-Filters multiple variables by the same or different filters Filter_input-Gets a Input variable and filter it Filter_input_array-get multiple input variables and filter them by the same or different filters.There are two types of filters:Validating Filter: Used to validate user input Strict formatting rules (e.g. URL or e-mail authentication) Re

, we put a test.properties file into our class directory, we use the ClassLoader to read the contents of it.The content of our configuration file is simple:User=rootpassword=123456The code is as follows:The operating result is:User:rootpassword:123456PostscriptThis article introduces the basics of reflection and the source of reflection . Class class, and tells about getting Class class object in four ways, but also introduced the class loader some knowledge, about reflection this article first

, gets the value through get (key), allows the storage of an empty object, and allows the key to be empty (since the key must be unique, of course there is only one);HashTable implements an image, all keys must be non-empty . In order to work efficiently, the class defining the key must implement the Hashcode () method and the equal () method . This class is an inheritance of the previous Java implementation and is usually better used in other classe

. Include (String Relativeurlpath): Use another page contained in the current location. 8, Page object "not used" The Page object is somewhat similar to the this pointer in Java programming, which refers to the current JSP page itself. The page is an object of the Java.lang.Object class. Page objects are not used frequently in the actual development process.Common methods for page objectsgetclass (): returns the class of object at that time.h

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

dynamically load the need to reuse the function class, the reflection code is we in the first three articles learned. Let's take a look at the reusable functional classes that require dynamic loading Hi Impl :Next, look at our client code:operation Result: The Before method of class Com.tgb.state.HiManage Hi methodClass Com.tgb.state.HelloImpl Hello!zhangsanThe After method bye method for class Com.tgb.state.HiManage To here a lang= zh-cn "en-US" lang= with jdk aop " reflectio