Java

Import java.util.ArrayList;Import Java.util.HashMap;Import java.util.List;Import Java.util.Map;Import Com.alibaba.fastjson.JSON;public class Listmap2json {/*** @param Lavender*/public static void Main (string[] args) {/* map map1 = new hashmap

Abstract class:Why use abstract classes?1, the method of the parent class in many cases there is no content. For example: USB is a parent class, inside the function body of the method is can not write, through subclasses can be rewritten.2, if the

1. Factory method Mode (Factory methods)The factory method pattern is divided into three types:11, the Common factory model , is to establish a factory class, the implementation of the same interface for some classes to create instances. First look

Here is mainly their own personal development encountered some small problems, their own to save up, to make up for their weak Java foundation, the great God do not laughed at1. DateFormat formatted HH and HH differences: Public Static

1 Public classJosephus {2 Public Static int[] Arrayofjosephus (intNumberintper) {34 int[] man =New int[number]; 5 6 for(intCount = 1, i = 0, pos =-1; 7Count ) { 8 Do { 9pos = (pos+1)% number;//Environmental

One of the rewrite rules: The overriding method cannot have a stricter access level than the overridden method limit.(but more broadly, such as the parent class method is the package access permission, the subclass's overriding method is public

Good article, recommend.Http://www.ibm.com/developerworks/cn/education/java/j-nio/j-nio.htmlJava NiO non-clogging technology is actually to take the reactor mode, or the Observer mode for us to monitor the I/O port, if there is content to come in,

1 What is the reflection mechanism? The reflection mechanism is in the running state, for any class, can know all the properties and methods of this class, for any one object, can call any of its methods and properties; This dynamically acquired

True and FalseAll conditional statements use the true or false of the conditional expression to determine the execution path.If-elseif (boolean-expression)StatementOrif (boolean-expression)StatementElseStatementIterationWhile, Do-while and for to

AbstractAbstract class: Do not know what is the specific type of things. Abstract class name1. Abstract classes cannot be directly new.2. Abstract classes can have no abstract methods.3. In an abstract class, there can be abstract methods or

Compare common keywords in Java to avoid confusionFinal: Used to modify a variable to indicate that the variable is the final variable and cannot be changedFinally: used when handling exceptions, indicating the final code block to

One, Stack space1, stack space storage data efficiency is high2. The data in the stack is managed according to the "advanced post-out" method3, stack space storage space is relatively small, can not store large amounts of data4. The JVM stores basic

Type Constraints:Importjava.util.List;Importjava.util.ArrayList;Importjava.util.LinkedList;/*** Created by Administrator on 2016/12/30 0030.*/ public classListgenericfooextendsList>{ Privatet[] fooarray; publict[] getfooarray () {returnfooarray;

T_user User Login Data SheetUser Login InterfaceJSP DevelopmentSubmit to servlet processing via POST requestServlet handles processing of connected databasesLogin successful client jump RequestDispatcher to main.jspThe error message is not

packagecom.test.collection;/*** Custom Implementation linklist * 1. Two-way linked list * Implementation principle: the underlying package node object (each node has 3 Parts: 1. The position of the last node, 2. Current node contents, 3. Position of

1.HasMap Custom Base version packagecom.test.collection;/*** Custom Implementation Map function * Map: Store key value pairs, find corresponding Value object according to key object *@authorChenx **/ public classMyMap001 {entry[] arr=Newentry[999];

[Java daily question] 20161230, java20161230 Package Dec2016; public class Ques1230 {int array = {1, 2, 3}; // 1 int array [] = {1, 2, 3 }; // 2 int [] array = {1, 2, 3}; // 3 int array [] = new int {1, 2, 3 }; // 4 int array = [1, 2, 3]; // 5}

LockSupport and locksupport Case 1: The subthread waits for the master thread to issue a license! Public static void main (String [] args) {Thread thread = new Thread () {public void run () {System. out. println ("subthread-> test pass permit! ");

Springmvc responsebody: How to return the object property to the front-end in the format of date, springresponsebody 1. Add dependency org. codehaus. jackson jackson-mapper-asl $ {jackson. version} com. fasterxml. jackson. core jackson-core $

Volatile variable, volatile For volatile, I found a bunch of materials and looked at it. After reading it, I wanted to find a method for testing. I tested it for a long time and felt like I did not. This book "a deep understanding of the Java