Java

1.0 map is a pair of a pair of existence, not directly with an iterator to operate, you must want to convert to set which is divided into (keySet and entryset two) type, and then use an iterator to take out the operation.(1) Eg:, create a set

The Times are progressing, and the drawbacks of a large number of XML-based configurations are obvious, as well as an interesting alternative to XML configuration and direct annotation configuration-javaconfig, which began to be incorporated into

In Java, memory management is divided into the following sections:Heap: An instance of an object, where all new things are stored.Stack: The stack area, which holds the base data type, constants, local variables, reference addresses of the

Reprint: http://www.cnblogs.com/hellokitty1/p/4386719.htmlBehavior of the object1. Breakpoint DebuggingA: Positioning (setting breakpoints)B: Start debuggingC: Stepping through the observation variable (F5 stepping F6 Single Step)D: Modify2 static

The second operation of the soft worker:1. Install an integrated development environment (available in Microsoft Visual Studio, Eclipse, or other tools) on your PC, requiring the environment to provide unit automated testing capabilities;2, record

package org.main;import java.io.bufferedwriter;import java.io.fileoutputstream;import  java.io.ioexception;import java.io.inputstream;import java.io.outputstreamwriter;import 

I, consider the static factory method alternative constructor Advantages: 1. There is a clear method name, convenient to call; multi-parameter constructors are prone to call error 2. You do not have to create a new object every time you call

Given a list, rotate the list to the right by K -places, where K is non-negative.For example:Given 1->2->3->4->5->NULL and k = 2 ,Return 4->5->1->2->3->NULL .The problem is not difficult, that is, to give a number k, and then from right to left

1. Static Nesting Classes PackageCom.wangfeng;Importjava.util.ArrayList; Public classOuter { Public Static classinner{PrivateString name; PublicInner (String name) { This. Name =name; } PublicString GetName () {returnname; } Public

1. public static list aslist (T ... a)List stooges = arrays.aslist ("Larry", "Moe", "Curly");2.public static int hashcode (long[] a)3.public static String toString (long[] a)4.public static int Deephashcode (object[] a)5.public Static short[]

Worker ThreadHave work to deal with, no job to wait. Equivalent to the cache and consumer portion of the producer consumer, in which the consumer part uses pooling strategies.Applicable environmentThe thread pool.Sample ExampleSlightlyPhase

1. Interfaces and classes used by the proxy mode1.1java.lang.reflectInterface InvocationhandlerObject Invoke (Object proxy, method, object[] args) 1.2 Java.lang.reflect.Proxypublic class Proxy extends Object

FutureGets the thread result when it is needed.Applicable environmentThe caller delegates the task that gets the result to an intermediate class, where both the caller and the task thread hold the class instance.When the caller needs to get the

An array is a collection of elements stored in a two-part memory block, and each element in the array must be of the same data type, partitioned by an index, and the index of the first element in the array is 0.Array lengthThe factor group is

Basic knowledge (1): Where to write where you want to goHttp://www.cnblogs.com/anrainie/p/5606570.htmlBasic Knowledge (2): Starting with the design UI frameworkHttp://www.cnblogs.com/anrainie/p/5609958.htmlBasic knowledge (3) Combining basic

Inherited keyword : extendsPrinciples of use of inheritance:① observe the classes to be used, identify common and unique characteristics and behaviors between them, migrate these common data to the parent class, and facilitate the reuse of methods

Java Notes 1: java notes If you want to write database-related software, you can study JDBK in depth. If you want to work on program software related to network information exchange, you can learn XML; if you want to develop and design large network

Writing high-quality code: 151 suggestions for improving Java programs (Chapter 1: generics and reflection ___ suggestion 7th ~ 105), java151Recommendation 102: Select getDeclaredXXX and getXXX as appropriate The Java Class provides many

Java Exception Handling Mechanism I. java exception Classification Java exception:(1) Error: a serious problem that cannot be solved by the Java Virtual Machine(2) Exception: the NULL pointer is abnormal and the network connection to the file that

JAVA 8 Optional class introduction and its source code, javaoptionalWhat is an Optional object? The so-called Optional object in Java 8 is a container object, which can contain a null or non-null value. If the value is not null, true is returned