Java

For Java socket programming, there are two concepts, one is serversocket and the other is a socket. A connection is established between the server and the client through the socket, and then they can communicate. First ServerSocket will listen to a

http://blog.csdn.net/luoweifu/article/details/10721543A further exploration of Java Foundation--throw and throwsAlthough I know some unusual handling, but also used some, but the difference between throw and throws is not very clear. Test it with an

Product Browsing details record the item ID and save it in the cookie package com.kt.servlet_qt;import java.io.ioexception;import  java.io.printwriter;import java.util.arraylist;import java.util.hashset;import java.util.list;

The difference between field, property, attribute,variable in JavaField: is defined as the fields used to hold the dataProperty:property is used to describe the characteristics of a class, so the property is broader than field meaning, because the

1. Array overview, definition Format* A: Array concept array is a collection of multiple elements that store the same data type. can also be seen as a container. arrays can store either the base data type or the reference data type. * B: Array

PackageTypeInfo;ImportJava.util.Random;classinitable{Static Final intStaticfinal = 47 ; Static Final intStaticFinal2 = RandomInit.rand.nextInt (1000) ; Static{System.out.println ("Initializing Initable"); }}classinitable2{Static intStaticnonfinal = 1

Basic knowledge:What is the anti-compilerAs we all know, the process of converting source code to binary execution code is called "compiling", such as compiling C source code into EXE executable file, then the process of binary code execution is

Arrays Common methodsArrays.tostring (int[] a) method-------> Return type is string, which can be used to produce a printable representation of an array, avoiding the use of loops to read the array values sequentially to printArrays.sort (int[] a)

Rule 1: Overriding methods cannot have more restrictive access restrictions than overridden methodsRule 2: Same method name, same parameter list, same return valueRule 3: An overriding method cannot throw an exception that is wider than the

Differences and usages of Java ArrayList, vectors, and linkedlist (RPM)ArrayList and Vector is to take the array format to store data, this array element is larger than the actual data stored in order to grow and insert elements, both allow the

Usage of class,public in JavaA Java Access Omphalos (Access specifiers)Java has public, protect, friendly, private four access rights, and these four access permissions are getting smaller.1. Friendly1) If the data member or method within a class

Instance:String poorname= datamap.get ("NAME"). ToString ();String villagename = Datamap.get ("ADDRESS"). ToString ();String filename=villagename+ "-" +poorname+ ". Doc";Response.setcontenttype ("Application/doc");Final String useragent =

Inherited syntax:Modifier Subclass extends Superclass {class Definition Section}Inheritance (inheritance) is implemented by the extends keyword, where subclass is called a subclass, Superclass is called a parent class, a base class, or a

Handling of exceptions1. For exception handling, one can directly handleThe second can be thrown ,Exception/io,sql, two large classes, compiled and run-time,And the way to handle it: You can use your own defined method, or the system's1-2. The way

Abstract is one of the most important features of object-oriented programming. In Java, there are two ways to embody the abstraction of OOP: interfaces and abstract classes. There are too many similarities, and there are too many different places.

1. Brief introduction of ThreadlocalThreadlocal instances are typically present in a class as static private static fields that are used to associate a thread. ThreadLocal is a thread-level local variable, and the following is a key point for thread-

Map is used to save data that has mappings, so there are two sets of data stored in the Map collection, a set of keys to hold the map, and a set of keys to hold the value corresponding to the key.The map key does not allow duplication.HashMap and

Spring -- c3p0 configuration details Today, let's talk about the c3p0 configuration in Spring in detail. Well, we will go directly to the topic without delay. Please refer to the specific configuration file below:  

Chapter 3 inheritance in the second quarter of Java3-1 Inheritance in Java ★Concept: inheritance is a kind of relationship between classes and classes. It is a kind of "is a" relationship. Figure: inheritance relationship-dogs and animals Note: in

Concurrent Programming-object combination and concurrent programmingObject combination 1. Design thread-safe classes 1. In the process of designing the thread security class, it should include the following three basic elements: 1) Find all the