As we all know,a thread is a separate process on your computer.you can run multiple threads all at the same time. multi-threaded code has the disadvantage of becoming quite complex very quickly,although java has some great classes for dealing with mu…

2017/6/30 转载写明出处:http://www.cnblogs.com/daren-lin/p/anonymous-classes-and-lambda-expressions-in-java.html 本来在查看官方文档中的collection介绍,介绍到如何遍历(traverse)一个容器时提到一个方法是聚合操作(Aggregate Operations),感觉这个写法比较简洁,而且从来没接触过,于是进一步了解.而为了了解Aggregate Operations,必须复习总结一下本文…

1.前言 匿名内部类在我们JAVA程序员的日常工作中经常要用到,但是很多时候也只是照本宣科地用,虽然也在用,但往往忽略了以下几点:为什么能这么用?匿名内部类的语法是怎样的?有哪些限制?因此,最近,我在完成了手头的开发任务后,查阅了一下JAVA官方文档,将匿名内部类的使用进行了一下总结,案例也摘自官方文档.感兴趣的可以查阅官方文档(https://docs.oracle.com/javase/tutorial/java/javaOO/anonymousclasses.html). 2.匿名内部类…

Every class can have a main method. That is a handy trick for unit testing of classes. For example, you can add a main method to the Employee class: test.java : import java.util.*; import java.time.*; class Employee { String name; double salary; Loca…

[src: https://blog.idrsolutions.com/2012/05/replacing-the-deprecated-java-jpeg-classes-for-java-7/] In the early days of Java, Sun produced a really handy set of classes to handle JPEG images. These included some really nifty little features like the…

20.1 并发得多面性 并发编程令人困惑的一个主要原因:使用并发时需要解决的问题有多个,而实现并发的方法也有多种,并且在这两者之间没有明显的映射关系. 20.1.1 更快的执行 速度问题初听起来很简单:如果你需要一个程序运行得更快,那么可以将起断开为多个片段,在单个处理器上运行每个片段. 并发通常是提高运行在单个处理器上的程序的性能,但在单个处理器上运行的并发程序开销确实应该比该程序所有部分都顺序执行开销大,因为其中增加了所谓的上下文切换的代价. 如果没有任务会阻塞,那么在单处理器上使用并发就没…

下面的内容都是从java编程思想一书中摘取出来,我认为很有产考价值,并且便于后续使用. 主要内容是记录继承thread和实现runnable接口两种方式的代码用法,及内部类中启用线程的用法. 1.首先看下一个继承Thread类的用法,通过第13行代码,在构造方法中通过start开启线程. 然后程序执行SimpleThread类的run方法. package concurrency; //: concurrency/SimpleThread.java // Inheriting directly…

Kotlin Koans 心印 Introduction 1.Hello, world! Simple Functions Take a look at function syntax and make the function start return the string "OK". In the tasks the function TODO() is used that throws an exception. Your job during the koans will be…

一.前言 这一节我们来了解下lambda表达式,主要关注以下几点: 行为参数化 匿名类 Lambda 表达式 方法 引用 二.行为参数化 1.概念 行为参数化(behavior parameterization)是用来处理频繁更改的需求的一种软件开发模式,可以将一段代码块当做参数传给另一个方法,稍后执行.这样,这个方法的行为就基于那块代码被参数化了. 也就是说 行为参数化: 让方法接受多种行为( 或战略) 作为参数, 并在内部使用, 来完成不同的行为. 2.需求频繁更改的实例 现在,我们来看一个…

When thinking about inner classes in java, the first thing that comes to my mind is that, WHY do we need to add inner classes to normal one? Leave alone all the specific details of the Java syntax, I think the reason is quite SIMPLE: we are human bei…

鄙人最近尝试着翻译了自己的第一篇英文技术文档.Java Nested Classes Reference From Oracle Documentation 目录 嵌套类-Nested Classes 为什么使用嵌套类-Why Use Nested Classes? 静态嵌套类-Static Nested Classes 内部类-Inner Classes 局部类-Local Classes 匿名类-Anonymous Classes 变量覆盖问题-Shadowing 序列化问题-Seriali…

Nested class types Usage and remark Advantage Disadvantage static member classes Use for public helper class, useful only in conjunction with its outer class. (Such as the operation types of a Calculater). Save memory. Class specific. Not instance sp…

http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

1. The diffrence between java.lang.StringBuffer and java.lang.StringBuilder? java.lang.StringBuffer: thread-safe, synchronized and not so faster. java.lang.StringBuilder: faster, performs no synchronization. 2. How to handle uncaught Exception for a…

Part 1 reference:http://jaxenter.com/lambdas-in-java-8-part-1-49700.html Get to know lambda expressions in Java 8. Few things excite a community of software developers more than a new release of their chosen programming language or platform. Java dev…

Java JVM 内存泄露——全解析和处理办法 [转载]   @author 小筐子 @address http://www.jianshu.com/p/bf159a9c391a         JAVA是垃圾回收语言的一种,开发者无需特意管理内存分配.但是JAVA中还是存在着许多内存泄露的可能性,如果不好好处理内存泄露,会导致APP内存单元无法释放被浪费掉,最终导致内存全部占据堆栈(heap)挤爆进而程序崩溃. 内存泄露 说到内存泄露,就不得不提到内存溢出,这两个比较容易混淆的概念,我们来分析…

收集自Oracle公司的10次(60道)电话面试全部问答(英语) Q: What environment variables do I need to set on my machine in order to be able to run Java programs?A: CLASSPATH and PATH are the two variables. Q: Can an application have multiple classes having main method?A: Yes…

转自:http://www.androiddesignpatterns.com/2013/04/activitys-threads-memory-leaks.html http://www.cnblogs.com/kissazi2/p/4125356.html A common difficulty in Android programming is coordinating long-running tasks over the Activity lifecycle and avoiding…

从诞生至今,20多年过去,Java至今仍是使用最为广泛的语言.这仰赖于Java提供的各种技术和特性,让开发人员能优雅的编写高效的程序.今天我们就来说说Java的一项基本但非常重要的技术内存管理 了解C语言的同学都知道,在C语言中内存的开辟和释放都是由我们自己来管理的,每一个new操作都要对于一个delete操作,否则就会参数内存泄漏和溢出的问题,导致非常槽糕的后果.但在Java开发过程中,则完全不需要担心这个问题.因为jvm提供了自动内存管理的机制.内存管理的工作由jvm帮我们完成.这样我们就不…

经过前面几章的简单介绍,我们已经大致了解了jvm的启动框架和执行流程了.不过,这些都是些无关痛痒的问题,几行文字描述一下即可. 所以,今天我们从另一个角度来讲解jvm的一些东西,以便可以更多一点认知.即如题:jvm是如何找到对应的java方法,然后执行的呢?(但是执行太复杂,太重要,我们就不说了.我们单看如何找到对应的java方法吧) 1. 回顾核心变量JNIEnv的初始化 如上一篇系列文章中讲到的,jdk执行的核心方法,实际上也是调用jvm或者hotspot的接口方法实现的,这其中有个重要变量…

前言 Java 反编译,一听可能觉得高深莫测,其实反编译并不是什么特别高级的操作,Java 对于 Class 字节码文件的生成有着严格的要求,如果你非常熟悉 Java 虚拟机规范,了解 Class 字节码文件中一些字节的作用,那么理解反编译的原理并不是什么问题. 甚至像下面这样的 Class 文件你都能看懂一二. 一般在逆向研究和代码分析中,反编译用到的比较多.不过在日常开发中,有时候只是简单的看一下所用依赖类的反编译,也是十分重要的. 恰好最近工作中也需要用到 Java 反编译,所以这篇文章介…

2016-12-17  21:10:28 吉祥物:Duke(公爵)    Logo:咖啡(爪哇岛盛产咖啡)  An overview of the software development process.          <编程语言吉祥物之Duke>:http://www.cnblogs.com/turingbooks/p/3585919.html <Java Tutorials Learning Paths>:http://docs.oracle.com/javase/tut…

原文地址 目录 介绍(Introduction) 相似点(Similarities) 编译单位(Compiled Units) 命名空间(Namespaces) 顶层成员(类型)(Top Level Elements(Types)) 基础类型(Basic Types) 类(Classes) 结构体(Structures) 接口(Interfaces) 泛型(Generic Types) 委托(Delegates) 枚举(Enumerations) 类型访问级别(Type Visibilities…

并发框架分类 1. Executor相关类 Interfaces. Executor is a simple standardized interface for defining custom thread-like subsystems, including thread pools, asynchronous I/O, and lightweight task frameworks. Depending on which concrete Executor class is being u…

Java基础常见英语词汇(共70个) ['ɔbdʒekt] ['ɔ:rientid]导向的                             ['prəʊɡræmɪŋ]编程 OO: object-oriented ,面向对象 OOP: object-oriented programming,面向对象编程 [dɪ'veləpmənt][kɪt]工具箱                              ['vɜːtjʊəl]虚拟的 JDK:Java development kit, j…

Hi guys, I am happy to tell you that I am moving to the open source world. And Java is the 1st language I have chosen for this migration. It's a nice chance to read some great books like "Effective Java 2nd Edition" and share the note for what I…

看到一篇关于handler和匿名类关于内存泄露的文章,觉得不错,充分发挥拿来主义,先放这儿看着! From:http://www.androiddesignpatterns.com/2013/01/inner-class-handler-memory-leak.html Consider the following code: public class SampleActivity extends Activity { private final Handler mLeakyHandler =…

In this tutorial we will discuss about different types of questions that can be used in a Java interview, in order for the employer to test your skills in Java and object-oriented programming in general. In the following sections we will discuss abou…

Normally, when you implement a simple, concurrent Java application, you implement some Runnable objects and then the corresponding Thread objects. You control the creation, execution, and status of those threads in your program. Java 5 introduced an…

http://docs.oracle.com/javase/tutorial/essential/concurrency/index.html Concurrency Computer users take it for granted that their systems can do more than one thing at a time. They assume that they can continue to work in a word processor, while othe…