java practice book

Many Java™ language methods, such as Thread.sleep() and Object.wait() , can be thrown InterruptedException . You cannot ignore this exception because it is a check exception (checked exception). But what should be done about it? In Java theory and practice this month, the concurrency expert Brian Goetz will explain Interruptedexception's meaning, why it throws in

Java Theory and Practice: using Volatile variables correctly Volatile variables in the Java language can be thought of as "light", and synchronized synchronized volatile variables require less coding and run-time overhead than blocks, but only part of the functionality that they can implement synchronized . This article describes several patterns for using vo

restricted on the object method, so that the thread can always hold the correct lock when accessing the data. The blocking mechanism makes it easier to construct a thread-safe class, because when the status of the closed class is used, the entire program does not need to be checked when analyzing the thread security of the class. Even if the closure feature ensures that all processing in the object is secure, you must note that problems may still occur after the object is published, such as H

Final keywords are often misused-they are used excessively when declaring classes and methods, but are not used enough when declaring instance fields. This month, Java practitioner Brian Goetz explored some useful final. Like in its cousin-CconstThe same keyword, according to the context,finalIt indicates different things.finalKeywords can be applied to classes, methods, or fields. When applied to a class, it means that the class can no longer genera

The new lock class improves synchronicity--but it can't be abandoned right now. SynchronizedJDK 5.0 provides a number of new and effective options for developers to develop high-performance concurrent applications. For example, a java.util.concurrent.lock class in the ReentrantLock Java language is synchronized replaced with the same memory semantics, the same lock, but with better performance under race conditions, and there are synchronized other fe

(); }/** * * */PublicvoidSendfinish () {sendfinish =True; }/** * * */PublicvoidRelease () {System.Out.println ("release!");if (BW! =Null) {Try{Bw.close ();}Catch(IOException e) {//TODO Print log.} }//In fact, using queue = null is enough.if (Queue! =Null) {queue.clear (); queue =Null; } }/** * * */PublicvoidSendmsg (String text) {if (Text! =Null !Text.isempty ()) {queue.add (text);}}PublicStaticvoidMain (string[] args) {Countdownlatch latch =New Countdownlatch (1); Asynchandler handler =NewAsyn

Apriori condition (precondition): Some methods contain a priori condition based on a state. For example, you cannot remove an element from an empty queue, and the queue must be in a non-empty state before the element is deleted. The operation of a state-based priori condition becomes a dependent state operation. In a single thread, if an operation fails to meet a priori condition, it can only fail, but in a concurrent program a priori condition may become true due to an operation performed b

1 Use the tool (Code->reformate code) in idea to reformat the code below, and then look at the Code menu to find a feature that feels best for you. Submit, plus your own study number watermark.public class Codestandard {public static void main (String [] args) {StringBuffer buffer = new StringBuffer (); Buffer.append ( ' S '); Buffer.append ("Tringbuffer"); System.out.println (Buffer.charat (1)); System.out.println (Buffer.capacity ()); System.out.println (Buffer.indexof ("Tring")); System.out.p

on hash The entire allocation process is artificially mastered, and when certain requests must be assigned to the specified server, the modifications are simpler Disadvantages: Large number of coding needs rigorous testing Need to proactively maintain a routing table, storage is an issue to consider When the request volume is large, the routing table capacity will increase, you can consider to deposit in Redis The above is my underst

"); System.out.println ("usage:democlient [Host=localhost] [port=9090]"); System.out.println ("This demo assumes you has a table called \" Example\ "with a column family called \" family1\ "); String host = "192.168.58.101"; int port = 9090; Use passed in arguments instead of defaults if (args.length >= 1) {host = Args[0]; } if (Args.length >= 2) {port = Integer.parseint (args[1]); } int timeout = 10000; Boolean framed = false; Ttransport transport = new Tsocket (host

input. Each line have the number of all possible ways to distribute D CDs among N nephews.Sample Input1 203 100 0Sample Output159049Ask N^d. Large number, Java, the large number of C + + template is really no love, decisive JAVA.Import java.io.*;import java.math.*;import java.util.*;p ublic class Main {public static void Main (string[] arges) { C1/>biginteger N; int D; Scanner cin = new Scanner (system.in); while (Cin.hasnext ())

The following information was drawn from the project:Https://www.cnblogs.com/whenever/p/5526420.htmlHttps://www.cnblogs.com/jpwz/p/5715852.htmlHttps://www.cnblogs.com/sddychj/p/6102192.htmlhttps://zzk.cnblogs.com/s/blogpost?Keywords=java+socket+ Multithreading __requestverificationtoken= Cfdj8gf3jjv4cttdney2uyrcgz0kcosvpzzwlayvpu5r95d1oz8nhsq1qxox6l_ S0tdix36-vqfer-yemgbxg29wz0fs1ft-swezszh4opfatuvkj4sdctgegzuvkv9kknpiiyjcjtrprjpj2jiy8x7rzzhmulspblixf

1.1 Practice of methods1.1.1 Method exercises to get a larger of two data1.1.2 Case Code IVpackage com.itheima_01;import java.util.Scanner;/* * 需求：键盘录入两个数据，返回两个数中的较大值 * * 两个明确： * 返回值类型：int * 参数列表：int a,int b */public class MethodTest {// 返回两个数中的较大值public static int getMax(int a, int b) {if (a > b) {return a;} else {return b;}}public static void main(String[] args) {//创建对象Scanner sc = new Scanner(System.in);//接收数据System.out.println("请输入第一个数据：");int x =

into the buffer or writes to the operating system.Asynchronous Io:aio-based on the idea of event-driven, implemented by Proactor mode. When reading and writing, just call the API's read or write method directly, both of which are asynchronous. When a stream is readable, the operating system streams the readable buffer into the Read method and notifies the application. When the operating system writes the stream that is passed by the Write method, the operating system proactively notifies the ap

Introduction to Java NIO (iii) from theory to practice: using NIO to read and writeGuibin.beijing@gmail.com OverviewReading and writing are the most basic IO processing. Reading from a Channel is very simple. We only need to create a Buffer and then require the Channel to read data to the Buffer. Writing is also very simple. You also need to create a Buffer to fill the data to be written into the Buffer, an

: Reflection function name * @ return ReflectionMethod obj: callback object */protected static function getPrivateMethod ($ strMethodName) {$ objReflectClass = new ReflectionClass (self: CLASS_NAME); $ method = $ objReflectClass-> getMethod ($ strMethodName ); $ method-> setAccessible (true); return $ method ;} The following is an example of calling another type of private method using reflection in java. We know that

LinkedList, because linkedlist to move the pointer.Add and remove,linkedlist are the dominant for new and deleted operations because ArrayList is moving the data.ArrayList space waste is mainly reflected in the end of the list to reserve a certain amount of space, while the linkedlist of the space cost is reflected in its every element needs to consume considerable space.ArrayList is based on an array implementation.LinkedList is based on a linked list implementation. This article is from the

Java.lang.instrument.instrumentation;import Org.apache.bcel.constants;import Org.apache.bcel.classfile.classparser;import Org.apache.bcel.classfile.javaclass;import Org.apache.bcel.classfile.method;import Org.apache.bcel.generic.classgen;import Org.apache.bcel.generic.constantpoolgen;import Org.apache.bcel.generic.instructionconstants;import Org.apache.bcel.generic.instructionfactory;import Org.apache.bcel.generic.instructionlist;import Org.apache.bcel.generic.methodgen;import Org.apache.bcel.g

version of the problem, may use Maven way, actually now can also be directly used in Java engineering development methods, see their favorite. In addition, the latest API development is simpler and supposedly more efficient, so .... Groping all is tears. Hope this article can make everyone less detours. 1 Maven way to establish the project (feasible, personally do not recommend, because the workplace without extranet) ----------specific installation

The practice of Java NIO Communication framework in telecom fieldThis article is wrong, Huawei Telecom Software V1 version of the logic frame composition and Huawei Telecom software V2 MVC version of the logical framework diagram two map is the same picture Another: I think the author encountered in this article due to synchronization IO caused by the history of the problem is more of the architecture pro