core java book

Java core package Others Java .* Javax .* Java. AppletJava. AWTJava. AWT. ColorJava. AWT. datatransferJava. AWT. DNDJava. AWT. EventJava. AWT. FontJava. AWT. GeomJava. AWT. ImJava. AWT. Im. SPIJava. AWT. ImageJava. AWT. image. renderableJava. AWT. PrintJ

references cannot exist independently and are always converted to instances of a functional interfaceYou can use this and the super parameter in a method referenceThis::equals equivalent to X->this,equals (x)3.5 constructor ReferenceA constructor reference is similar to a method reference, except that the method name is new. For example, Person::new is a reference to the person constructor. Which constructor is called depends on the context.You can establish a constructor reference with an arra

[] getdeclaredannotations ()//returns TRUE if the program element is a specified type annotation adornment, otherwise returns Falseboolean Isannotationpresent (classThe example code that parses our custom annotation MethodInfo above is as follows (Annotationparser.java):public static void Main (string[] args) { try { Class cls = annotationtest.class; For (Method method:cls.getMethods ()) { MethodInfo MethodInfo = method.getannotation (methodinfo.class); if (me

Multicore CPUs are now the mainstream. Using multi-core technology, can effectively play the ability of hardware, improve throughput, for Java programs, can implement concurrent garbage collection. However, the use of multi-core technology in Java also brings some problems, mainly because of multi-threaded shared memor

Summary Author: Gucci flying e Blog: www.v246.com QQ: 28095553 Email: aquaqu (circle. a) gmail.com This article is original from the ancient brake flying e. For more information, see the source! The following is the source code: [Full text] Author: Gucci flying e Blog: www.v246.com QQ: 28095553 Email: aquaqu (circle. a) gmail.com This article is original from the ancient brake flying e. For more information, see the source! This method has been verified by practice, is b

4.1. Introduction to object-oriented programmingobject-oriented Programming, or OOP for short, was the dominant programming paradigm these days, having replaced T He "structured," procedural programming techniques that were developed in the 1970s. Since Java is object-oriented, and you had to be familiar with the OOP to become productive with Java.An object-oriented program is made of objects. Each object is a specific functionality, exposed to its us

JAVA concurrencyParallel programming in Java is complicated, and I don't understand it deeply. But recently, due to the parallel training of classifiers, pondering a little, there are errors please correct me. Just a rough introduction.Many problems we use sequential programming can be solved, but some problems if you can use multi-threaded parallel execution of the task of which can greatly improve the tim

limitation mentioned above is applied during compilation and does not work during runtime. Now that we understand this, we can imagine how to pass in the Set object to the non-qualified type value under the type limitation through the compilation period. So let's take a look at the following question. The solution has been implemented in the above Code.How to pass a String object to an Integer-type generic object? Method method = collection3.getClass (). getMethod ("add", Object. class ); With

The error details are as follows:: [6/27/13 15: 54: 49: 679 CST] 00000043 systemout o error-An error occurred while obtaining the instance of the specified object [appendixmgr! Check the configuration file! -Com. TRS. dreamfactory. createobjectbyid (dreamfactory. java: 79) Org. springframework. beans. factory. beancreationexception: Error creating bean with name 'appendixmgr 'defined in file [/opt/IBM/WebSphere/appserver/profiles/invalid rv06/installe

is to ensure the uniqueness of the class name.Import of Class 7.1A class can use all the classes in the owning package, as well as the public classes in other packages.You can only import a package using an asterisk (*), and you cannot import all packages prefixed with Java using Import java.* or import java.*.*.It is possible to add a specific package name to r

1. Description:[How to make JS and Java securely call each other in WebView] (http://www.pedant.cn/2014/07/04/webview-js-java-interface-research/) "Core JS full parsing2. Core JS parsing is as follows, welcome to shoot Bricks!!!javascript: (function (Win) {console.log ("hostappinitialization Begin "); //win. Hostapp Ob

)Analysis: When a class is loaded, from the parent class to the subclass, from top to bottom, execute the static code block, and then execute the main function , if there is a statement of the new object, The construction code block and constructor of the binding are executed. Note: static code blocks have and execute only once14. What is the result of the following code?public class a{public static void Main (string[] args) {String str;System.out.println ("" + str);}}Analysis: The above code w

block first, and the post constructor)Parse: When a class is loaded and finished, from the parent class to the child class. From top to bottom. Run the static code block first, then run the main function , and if there is a statement for the new object, run the bound construction code block and constructor. Note: static code blocks are available and run only once14. What is the execution result of the following code?public class a{public static void Main (string[] args) {String str;System.out.

I recently concluded that I have not improved my skills. I am ready to start training. Write down this and give myself a goal. The core APIs of Java are very large, which makes it very convenient for developers. Many people often comment that java makes programmers stupid.However, I think some content must be mastered. Otherwise, it will be difficult to use

The core concept of Java: interface (interface)Interfaces are at the same level as classes, and in fact, interfaces are a special kind of abstract class.Such as:Interface ia{}Public interface: Open InterfaceSimilar to a class, a file can have only one public interface and is the same as the file name.A public interface and a public class cannot be defined in a file at the same time.In an interface, all meth

Well known in. NET, the key generated by the RSA class is in XML format, while other languages such as Java generally use the PKCS8 format key, JavaScript generally uses the PKCS1 format. We in the development process is likely to encounter the need to interface with other languages developed API, if we encounter RSA encryption and decryption, we must ensure that key is the same, in order to ensure the correct processing of data, we definitely need to

) proxy.newproxyinstance ( fly.getclass (). getClassLoader (), new class[] {flyable.class}, new Objecthandler (fly)); } public static void Main (string[] args) { flyable fly = Flyfactory.getflayimpl (); Fly.addwing (null); System.out.println (Fly.fly ());} }Core Class Description:The JDK provides a class named Proxy.newproxyinstance (All-in-one). Where is the first parameter for the loader th

Exception handlingThe parent class in the exception structure Throwable class, its Exceptionlei class and the error class. What we can catch in the program is the subclass exception of exception.Error at System level: Error in Java Runtime Environment, we are not controllable.Exception is a program-level error: we can control it. 1) catch Exceptions in two ways: one is to add Try-catch to catch the exception, and the other is to declare the exceptio

the source file. If you do not place the package statement in the source file, the class in the source file is placed in a default packet.The compiler does not check the directory structure when compiling the source files. So as long as the source file is not dependent on other packages, the compilation error does not occur even if it is not in the declared package, but a run error occurs because the virtual machine cannot find the file.Package Scope:The parts marked as public can be used on an

Java core programming-byte stream of IO stream (2), javaio 1. byte stream A 1.1-byte stream is a stream that operates byte. Byte streams can operate on any data, such as media data, music, movies, and images. Of course, they can also operate on characters. Byte stream is based on byte stream, we know that a byte is 8 binary bits, a byte corresponds to an English character in the UTF-8, people found that usi