Java

Project description The project uses the MAVEN organization, and the only dependency of JDBC is the Mysql-connector-java pom dependency as

Grammar Description Comments // Single-line Comment /*...*/ Multi-line comments /**...*/ Document comments Separator ; Each Java

To find the median of an unordered array, it is convenient to use a counting sort to get the time complexity O (n), which discusses how to locate using a quick sort.1, the median definition2. Algorithm idea3. Java Code Implementation4. Analysis of

The sleep () method suspends the thread for a period of time, and the Wait () method blocks the thread until it is woken up or the wait time times out.The difference is specific as follows:1 different principlesThe sleep () method is a static method

1. What is the structure of HashMap?Two-dimensional structure, the first dimension is an array, the second dimension is a linked list2. What is the process of the Get method?First call the key's Hashcode method to get the hash value of the object,

The idea of looping through the list of elements using a for loop is problematic, but you can use the enhanced for loop, and then find an error today when using it, then go to science a bit, and then find that this is a misunderstanding. Here's a

Socket programmingSockets use TCP to provide a mechanism for communication between two computers. The client program creates a socket and tries to connect to the server's socket.When the connection is established, the server creates a Socket object.

Service Provider Interfaces Services provides discovery, dynamic replacement of discovery mechanisms Example: An interface: Public Interface Calc { Logger Logger = Loggerfactory.getlogger (Calc.class); Object Calc (int calctype);}Two

Directory I. Background knowledge Two. Introduction to JVM Virtual machine memory Three. Garbage collection Four. Some changes brought about by JAVA7 and 8 For a Java programmer, it is true that in most cases there is no

Some understanding of object construction.Default Domain InitializationIf the domain is given an initial value in the constructor, it is automatically assigned the default: The value is 0, the Boolean value is False, and the object reference is null.

When you need to program in a multithreaded environment using Java threads, it is important to understand the thread cycles and the state of the threads in Java. By implementing the Runnale interface or inheriting the thread class, we can create a

Communicate using a non-connected datagram (UDP)What is datagram?The datagram is an independent packet transmitted on the Internet, whether the datagram can reach the destination correctly, the time of arrival, the order and the correctness of the

A simple understanding of OSGiJust like a Java Web application needs to run in a container such as Tomcat, WebLogic. The OSGi packages developed by programmers also need to be run in OSGi containers. Currently, the main OSGi containers include

One.Next you want to do a sort of student, should make a comparison method. By observing the other part of the program, students have a comparative approach and are ranked by age.Now the key to sort, (I think who called the key, who called the value

Multiple threads are working on the same resource, but the tasks of the threads are not the same, so that each thread can use the resources efficiently by some means.This means: Waiting for a wake-up mechanism, also known as communication between

In recent days, in a project, you need to use spring's scheduled tasks in the project, but in the operation of the database is always unable to correctly insert the data, after viewing only found: Because the service layer can not be injected into

What is the difference between HashMap and Hashtable? hashmaphashtableDifferences between HashMap and Hashtable 1. Different inherited parent classes: The parent class of HashTable is Dictionary. The parent class of HashMap is AbstractMap; 2. thread

Analysis of the JavaWeb project architecture-Redis distributed log queue, javawebredis Abstract: The architecture, distributed, and log queue titles all look at the publisher, which is actually a log collection function, but a Redis is added in the

Integration configuration of marven and Eclipse and integration of marveneclipse Maven, as a project construction tool, is very popular in the development process and can help manage the bao dependency problems in the project. In addition, many of

Use Baidu UMeditor Rich Text Editor java, umeditorjavaUse Baidu UMeditor Rich Text Editor java 1. Introduction UMeditor is a lightweight Rich Text Editor.UEditor is much smaller. It is an online Rich Text Editor tailored to meet the needs of portal