java adf tutorial

Java tutorial -- difference between int and Integer: javaintinteger First, let's talk about the difference between int and Integer: The following is an example: 1 package syswar.cc; 2 3 public class IntegerCompare { 4 5 public static void main(String[] args) { 6 // TODO Auto-generated method stub 7 Integer a1 = 2; 8 Integer a2 = 2; 9 10 Integer b1 = 150;11 Inte

(9999)//client own port because UDP is not a connection-oriented Ds.send (DP);d s.close ();}}　　TESTUDP Clientimport Java.net.*;import java.io.*; public class Testudpclient{public static void Main (String args[]) throws exception{long n = 10000L; Bytearrayoutputstream BAOs = new Bytearrayoutputstream ();D ataoutputstream dos = new DataOutputStream (BAOs); Dos.writelong (n); byte[] buf = Baos.tobytearray ();//convert Long data into a character array, input System.out.println (buf.length); Datagra

Let's get to it.Math class: Mathematical class, including ABS () absolute value, sin () sine function, cos () cosine function, etc.Random class: Gets the stochastic number of various data typesExample: Import java.util.random;/** * Demo get random number * @author Genius Federation-Yukun */public class Mathdemo {public static void main (string[] Arg s) {//Create the Random object random random = new random ();//Gets a double of type 0 to 1 for a double D = random.nextdouble (); System.out.printl

array array3 (only in ascending order) Arrays.sort (ARRAY3); System.out.println ("---------- sorted array ----------");//Iterate through the sorted array array3arraytostring (ARRAY3); SYSTEM.OUT.PRINTLN ("----- using dichotomy (binary) to find elements -----");//using dichotomy to find elements in an array, the lookup array must be sorted in ascending order int Index=arrays.binarysearch (array3,4); System.out.println ("4 in the array array3 subscript is:" +index);} /*** converts an array to a s

List.add (f); List.add (s);//To use a member specific to the object, the type conversion fatherf1= (Father) list.get (0) must be enforced; F1.work (); sons1= (Son) list.get (1); S1.play ();/******************* used a generic collection ************* /system.out.println ("-----------------------------");/** create generic collection objects, you can use ArrayList, You can also use linkedlist* Note: *1, generics can only use reference types, cannot use basic data types * such as:listGeneric SetPa

the linked list privatenodelast=null;// is used to store the collection length Privateint size=0;//method of adding elements Publicvoidadd (objectobj) {//Create node object nodenode= newnode ();//node stores the added element node.element=obj;//determines whether the first node is nullif (first== NULL) {//The first node for the description is the first time the element is added first=node;//sets the last node of the first node to its own first.next=node;} Determines whether the last node is Nul

); List.add (s);//You must force type conversion Father f1 = (Father) When you want to use members that are specific to the object List.get (0); F1.work (); son S1 = (son) list.get (1); S1.play ();/******************* uses the generic collection ********************/system.out.println ("-------- ---------------------"); */* Create generic collection objects, you can use ArrayList, or you can use LinkedList * Note: * 1, generics can only use reference types and cannot use basic data types * For e

private node fi RST = null;//is used to store the last node of the linked list private node end = null;//used to store the collection length private int size = 0;//method to add elements public void Add (Object obj) {/ /Create Node object nodes node = new node ();//node stores the added element node.element = obj;//Determines whether the first node is nullif (primary = = NULL) {//First node is the first time the element is added. = node;//Sets the first and last nodes of a node to their own fir

node fi RST = null;//is used to store the last node of the linked list private node end = null;//used to store the collection length private int size = 0;//method to add elements public void Add (Object obj) {/ /Create Node object nodes node = new node ();//node stores the added element node.element = obj;//Determines whether the first node is nullif (primary = = NULL) {//First node is the first time the element is added. = node;//Sets the latter node of the first node to its own first.next = n

queue is often busy, and the other queue is very easy. RABBITMQ does not know that these are still evenly distributed messages.The reason for this is that RABBITMQ only forwards messages when the message arrives at the exit of the queue, and it does not care about the number of messages that have not reached the message consumer. It just blindly sends odd messages to a consumer, even to another consumer.The way to solve the problem is to set Prefetchcount = 1, which is like telling RABBITMQ eac

A set of ERP system will have CRM, it is impossible to say that all my data are scattered, you want to use just write one. You go out and talk to people, you must say I have something here, and then you can tell people you do is invoicing. Ask the CRM or the financial system you say it's not my responsibility. If you've ever been in touch with a similar system, you can say that I've also done CRM, so to speak. We connect directly to the existing financial system, and you just push it out and you

month, the price should be in what paragraph. Suddenly its price is very low, the system thinks this time is more suitable for purchase. Is the price very low when must buy? You'll have to watch your inventory. The same is true for sales, and we've already estimated that this product will have a big gain by September, and it's going to have a big gain by September. This year also should have, even if it is not up to the highest, according to the year, the first annual increase of 2%, the second

Read the previous article:Java multi-thread synchronization tutorial-BusyFlag or Lock (on)We first develop a BusyFlag class, similar to Simaphore in C ++. PublicClassBusyFlag { ProtectedThreadBusyflag =Null; ProtectedIntBusycount = 0; PublicSynchronizedVoidGetBusyFlag (){ While(TryGetBusyFlag () =False){ Try{ Wait (); }Catch(ExceptionE ){} } } PrivateSynchronizedBooleanTryGetBusyFlag (){ If(Busyflag =Null){ Busyflag =Thread. CurrentT

Data Structure tutorial (Java description) edited by Xu xiaokai-review abstract 05 Chapter 5 tree and binary tree The nature of the tree: 1. The number of knots in the tree is equal to the number of all knots plus 1. 2. In the tree with a K Degree, at most K ^ (I-1) knots (I> = 1) on the I layer ). 3. K-tree H depth has at most (K ^ h-1)/(k-1) nodes. 4. The minimum depth of K-tree with N nodes is... Binary

Data Structure tutorial (Java description) edited by Xu xiaokai-review abstract 03 Chapter 1 linear table Sequential storage and operation implementation of linear tables Public class sequencelist implements list {final int maxsize = 10; // array initial length private object [] listarray; // array declaration, element type: objectprivate int length; // current length of the linear table // Operation Public

File classJava.io.File class represents system file nameCommon construction methods for the file class:The public file (String pathname) creates a file object with pathname as the path, and if pathname is a relative path, the default current path in the system propertyPublic file (string parent, String child) takes the parent path to the father, and children creates a File object for the subpathThe static property of file, string separator, stores the path delimiter for the current systemFile Co

, state mode, Command mode, responsibility chain mode, proxy mode, etc.27th Lesson: Sixth Week outline code for the design job28th Lesson: The Sixth Zhou Teacher Example explains one29th Lesson: The Sixth Zhou teacher example explanation two30th Lesson: Seventh week operation and corresponding mode: Integrated application generator mode, prototype mode, Memo mode, state mode, Command mode, responsibility chain mode, proxy mode, etc.31st Lesson: Seventh Week outline code for design job32nd Lesson

"FilesystemutilsFilesystemutils contains some practical methods that the JDK does not provide to access the file system. Currently, only one method for reading the free space on the hard disk is available. Note that the command line is used instead of the local code.Long freeSpace =filesystemutils.freespace ("c:/");Endian class LibraryDifferent computer architectures use different conventions for byte ordering. In so-called "low-priority" architectures (such as Intel), low-bit bytes are in the l

The difference between the Start method and the Run method in Threads-java Tutorial In the thread, if the Start method calls the Run method sequentially, why do we choose to invoke the Start method? Or the difference between calling the Start method and the Run method in a Java thread. These two issues are two very popular beginner-level multithreaded intervi

development, some are pure technology, with the Vim editor used to, there is a Linux graphical interface to develop, such a person ... I find it hard to understand, the graphical interface you do not use Windows Linux Ah!I think many of the people who read this article now are not technically big. So what are we going to do? Wouldn't it be a little too hasty to go without thinking about running?This is my 10-second self-criticism.As for Linux, there will certainly be a chance for everyone to ge