learn java using netbeans

ois.close (); at}Catch(IOException e) { - e.printstacktrace (); - } - } - if(NULL!=bis) { - Try { in bis.close (); -}Catch(IOException e) { to e.printstacktrace (); + } - } the if(NULL!=Oos) { * Try { $ oos.close ();Panax Notoginseng}Catch(IOException e) { - e.printstacktrace (); the } + } A if(NULL!=Bos) { the Try { + bos.close

Recently learning swing programming, according to the teacher's teaching video learning using java.awt.*, javax.swing.*, java.awt.event.* package for a simple tank war game programming, Learning JFrame, JPanel and other containers and components of the use of Learn the various ways to draw graphics using graphics, as well as some event monitoring and processing m

This article explains in detail:1, the basic use of Cookies demo2. Demo Cookie access rights3. Demo Cookie Deletion4, using cookies to display the user's last login time5, using the cookie technology to display the user recently browsed several pictures6, test Firefox browser in the end how many cookies and a cookie max for how big 1, the basic use of Cookies demo INDEX.JSP: Xml:

Java data Types : A total of 11 data types, based on how they are used, are divided into basic types and reference types. Basic types: Byte (1 bytes), short (2 bytes), int (4 bytes), Long (8 bytes), Float (4 bytes), double (8 bytes), char (2 bytes), Boolean (indeterminate, determined by the JVM), where Byte, short , int, long is integer, float, double is floating point, char is character, Boolean is Boolean typeReference type: Class, Interface (interf

When I was young, I always liked to write the value of the parameter in the code to die, to run it again, portability is too bad. Since the use of the properties class, it is easier, the code is a little more standardized.That is, the commonly used, often need to modify the parameters placed in the Xx.properties file, using the properties class provided in Java to read the parameter values in the file, so a

. 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

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

1 PackageCom.hanqi;2 3 Public classXiyoujirenwu {4 5 Doubleheight;6 7 String weapon;8 9 String name;Ten One voidPrinetname () A { - System.out.println (name); - } the - voidPrinetweapon () - { -System.out.println ("Weapon" +weapon); + } - + Public Static voidMain (string[] args) A { atXiyoujirenwu SW =NewXiyoujirenwu (); -Sw.name= ("Monkey King")); -Sw.weapon= ("Ruyi Golden Cudgel"); -System.out.println (sw.name+ "

) If the inner class attribute is the same as the external property name, call the internal if you want to call the external required new object4) How to create the object: Inner in = new Inner (); When creating a guide package5) Static internal classes are mainly used in builder mode4 , local inner class1) The declaration position of the local inner class is placed in the method2) cannot use modifier3) Non-static properties and methods can appear inside4) Create object: Only in methods that dec

Would show you the tackle various tree questions using iterative inorder traversal. First one is the iterative inorder traversal using stack. Hope everyone agrees with this solution.Question:binary Tree inorder Traversal PublicListinordertraversal (TreeNode root) {ListNewArraylist(); if(Root = =NULL)returnlist; StackNewStack(); while(Root! =NULL|| !Stack.empty ()) { while(Root! =NULL) {Stack.push (

void Main (string[] args) { testoverload t= new Testoverload (); T.max (3,4); This is called Max (int a, int b) This method short a = 3; Short B = 4; T.max (A, b); Here is the method of Max (short A, short b). } Ii. Overloading of construction methods As with normal methods, the construction method can also overload Package cn.galc.test; public class Person { int id; int age; /** * Construction method */Public person () { id=0; age=20; } /

Tags: oat namespace mysql type tin sign approximate dataEstablishment of the table of norms1. The expression is the concept of the field, must be named using IS_XXX, the data type is unsigned tinyint (1 means yes, 0 means no).2. Table names do not use plural nouns.3. Disable reserved words.4. Decimal type, the use of float and double is forbidden.5. The name of the table is best added to the "Business noun _ table role".6. Update Field comments when m

1 PackageCom.hanqi;2 3 Public classLadder {4 5 DoubleShangdi;6 DoubleXiadi;7 DoubleGao;8 DoubleMianji;9 TenLadder (DoubleShangdi,DoubleXiadi,DoubleGao) One { A //using parameters to initialize properties - //This represents the current class - This. Shangdi =Shangdi; the This. Xiadi =Xiadi; - This. Gao =Gao; - - } + //method naming: verb + name; verb First letter low

to the parameters;3. Construct blocks of code : Generally the same initialization is placed in the construction code block, and when new object is constructed, the code block is executed before the method body in the construction method is executed;4. The object can be used as the formal parameter of the method, in the method, modifies the attribute value of the parameter object, in fact, modifies the attribute value of the argument object;And the parametric is re-assigned such as car = new Car

");}}Example 2 : Public class Test6 { Public Static void Main (String[] args) {D d = new d ();D.start();Scanner Scanner = new Scanner(System. in);Scanner.next ();Break the execution of a thread by throwing an exceptionD.interrupt();}}class D extends Thread{@Override Public void Run () {System. Out.println ("to Sleep");Try {Thread. Sleep (5000);} Catch (interruptedexception e) {System. Out.println ("awakened");}System. Out.println ("Natural Awakening");}}3 , five states of thread (also called lif

approach with production products2) is the parent of the production product3) A variety of products, such as2 , key detailsThe subclass of the factory pattern needs to inherit the product's parent class, and the type of the factory method return value is the parent class type of the product, but the object of the product subclass is actually put back, and the factory method needs to have parameters in order to determine the production of that super-3 , the role of the factory model:1) Mass prod

Com.ray.ch11.Test.test (test.java:12)At Com.ray.ch11.Test.main (test.java:21)We lowered some of the code, but the subject remained. Then we put the integer in the class, we can see from the output, direct error. The reason is that the integer does not have a default constructor.Because of the problems that appear above, we recommend the following to show how the type object is created.2. Instances of created types displayed(1) Using factory objects t

First, you can intuitively understand the annotations by using the @suppreesswarnings application: by System.runfinalizersonexit (true), a compiler warning is raised @SuppressWarnings ("deprecation") @Deprecated Add a method directly to the class that you just added, and add the @deprecated callout to call this method in another class. @Override public boolean e

I now have a lot of people around to learn Java, as long as a mention of learning the Java language, we immediately think of the tool is Eclipse,myeclipse,netbeans and so on.Perhaps we are used to the VC, the integrated development environment has too many dependencies. However, I personally feel that it is necessary f

JAVA basics: use Java to start Object-Oriented Programming-general Linux technology-Linux programming and kernel information. For more information, see the following. Are you switching from traditional procedural programming to object-oriented development models? Still want to enter the expanded Java World? You will not feel lonely. thousands of developers are in