j2se

At this stage is preparing a soft test, need to learn the Java version of the design pattern, so learning J2SE became the first preparation, understand the basic Java grammar, for better learning design model to lay the groundwork. The JAVA2 platform includes a Standard Edition (J2SE (Standard Edition)), an Enterprise Edition (Java EE (Enterprise Edition)), and a miniature version (J2ME (microedition)) thr

J2SE Enumeration In the past, we had to use an integer constant instead of an enumeration, and with the release of J2SE 5.0, the method was finally gone. A simple enumeration type is defined as follows: public enum Weather { Sunny,rainy,cloudy } Enumerations can be used in switch statements: Weather Weather=weather.cloudy; Switch (weather) { Case SUNNY: System.out.println ("It ' s Sunny"); Break

First, Java is what java is the generic term for the Java Language and the Java platform. the Java language is the same as C # , and the core is oo, and in comparison,Java to do better. Java is made up of four aspects:? The Java programming language, or syntax.? Java file format, which is the suffix of various folders and files.? The Java Virtual machine (JVM), the interpreter that processes the *.class file.? Java Application Interface (Java API). Java is divided into three systems, namely:

On the first day of the job today, Chen Zexin and I told a part of the knowledge about this part, the main analysis of the Java EE and J2SE, first J2SE and. NET are some of the basic knowledge of programming, classes, objects, (front-end???? ）Java EE is an enterprise-class application knowledge, mainly by 1. Application 2: Container (Tomcat WebLogic) 3: ComponentAlso told a part of the knowledge, where the

You are welcome to correct me! －－－－－－－－－－－－－－－－－－－－－－－－－－－－－ EE or j2se? JNDI works with both JNDI (Java naming and directory Interface) allows applications to access various naming and directory services through a common interface. The following features characterize the schema of the Jndi. Like JDBC (Java Database connectivity), Jndi is not a service, but a set of interfaces; It allows applications to use standard APIs to access many different direc

In j2se 5.0, Java introduces many new features. This article mainly introduces static import. Static import is mainly used to help developers create and use global constants and static methods. To use this new feature, you must first download the latest j2sdk 5.0 from java.sun.com. In objective Java, the author once mentioned that defining constants in interfaces is a bad way to use them. We should always use interfaces to define types. However, in a

It took eight days to complete the j2se process. To be honest, the enthusiasm at the beginning was particularly high, and each part of the video would not be more than 30 minutes, but it was a bit impetuous at the end. This is a bad habit. Resolutely put an end to it. The following is a summary. First, we have a macro control over j2se. Here is a one-to-one introduction! Java basics: Java is a cross-platfo

J2SE 1.5 provides the "autoboxing" and "auto-unboxing" mechanisms that allow compilers to automate the transformation between the base type and their wrapped objects, thus allowing for a simpler way to avoid some of the hassle of having two sets of type systems in parallel. This paper introduces the usage, essence, timing, limitation, influence of the overload mechanism and the hindrance to the performance of autoboxing/auto-unboxing mechanism. Tradi

override some methods as needed. The policy file is configured according to the permissions of the application code. Here's an example to illustrate the use of a custom security manager:The custom class Mysecuritymanager inherits from SecurityManager, overriding the Checkread () method.publicclass MySecurityManager extends SecurityManager { @Override publicvoidcheckRead(String file) { //super.checkRead(file, context); if (file.endsWith("not")) {

1. Find the number of occurrences of substring in a string2. CodePackage Test;public class Teststringcontain {public static void main (string[] args) {String str = "Javakkjava--java99javah Ajava98098098098java "; String subStr = "java"; int count = 0;int FromIndex = 0;int index = -1;while (index = str.indexof (substr,fromindex))! =-1) {//Every time you find SUBSTR, move Fromindex down substr.length () length Fromindex = index + substr.length (); count++;} System.out.println (count);}}　　3. Runnin

1. Use java.io related tree to display file structure2. Determine if the given path is dir, is recursive, and each recursive layer is indented once3. CodePackage Test;import Java.io.file;public class Testhierarchical {public static void main (string[] args) {File File = new Fi Le ("d:/workspaces/eclipse/test"); Tree (file, 0);} private static void Tree (File f, int level) {String prestr = ' "; for (int i = 0; I 　　4. Operation Result:JAVA-J2SE Learning

ReferencesA. Do not rewrite the Finalize method2. Overriding the Finalize method3. When the Finalize method occurs this escapeFour, this is a virtual referenceUnlike soft references, weak references that automatically reclaim memory, the existence of virtual references (although memory is still recycled) tends to send notifications when an object is determined to be recycled (the reference object in the virtual reference does not determine whether the memory has been reclaimed, and the soft and

This article is my sister-in-law on how to master Java (j2se) (hereinafter referred to as the standard article) and raises standards, however, it seems impossible to tell new users how to reach that standard. First of all, it is difficult to reach this standard. It is generally impossible to reach this standard without three years. It is also impossible to cultivate the experience of practical projects. The following will explain why. Then we will giv

Recently, I have been viewing j2se interface layout and event control, for example, processing list right-click events on the interface. Mouselistener-mouse listenerTool Actionlistener -- parent class of all listeners Itemlistener -- used to capture events generated by components with items Sample Code: Import Java. AWT. *;

*/public class named elinked {// Number of monkeys in the circular circle private int num; // The first monkey, that is, 1 private monkey firstmonkey = NULL; private monkey tempmonkey = NULL; // create a number of monkey circles with num public incluelinked (INT num) {This. num = num; For (INT I = 0; I Package cn.wwh.www.exe rcise. selectmonkey; import Java. util. role;/*** role: 2. using a circular linked list to deal with the Monkey King's question * the greatest difficulty is to format t

Basic concepts of threadingthread creation and startup Public classTestThread1 { Public Static voidMain (String args[]) {Runner1 R=NewRunner1 (); R.start (); //R.run (); //thread t = new Thread (r); //T.start (); for(inti=0; i) {System.out.println ("Main Thread:------" +i); } }}//class Runner1 implements Runnable {classRunner1extendsThread { Public voidrun () { for(inti=0; i) {System.out.println ("Runner1:" +i); } }}TestThread1Multi-threading mechanism of

1.java identifier: hellworld--Hello world can not space DataClass--dataclass# # _983--98.3 digits start. $bSS 5_C7--Class keyword2, keyword class void goto const3.JAVA constant "123" ' a ' 3.34 true,false;4.java variable final int i = 100; Type varName [=value][,varname=value]; Local variable/member variable basic/reference variable Testvar.java5. Data type: base data type numeric integer byte short int long float float double character type (char) Boolean (Boolean) reference data type class int

Application Window Program Design in J2SE environment (system class Frame/interface ActionListener/AWT class) Step 1: Design the application window program in Jbuilder Environment 1. Start Jbuilder 2. Create an empty project for the application 3. Create a source java File 4. Add the basic structure of the application and the Code for generating the window.// A comments section --------------------/*A comment*/// Set part of Package B ----------------

** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.**** This software is provided as-is without warranty of any kind,** Not even the implied warranty of merchantability. The author** Of this software, assumes _ No _ responsibility for any** Consequence resulting from the use, modification, or** Redistribution of this software.**/ Package com. kindani; // Import javax. servlet. ServletContext;Import java. util .*;Import java. io. InputStream;Import java. io. IOException;Import jav

Source: http://www.study-code.com/java/j2se/66419.htm Package com. test; Import java. awt. Dimension;Import java. awt. Rectangle;Import java. awt. Robot;Import java. awt. Toolkit;Import java. awt. image. BufferedImage;Import java. io. File;Import javax. imageio. ImageIO; /*************************************** ***************************************** This JavaBean can be called directly in other Java applications to implement "photo" This JavaBean i