Android应用性能优化:异步处理与多线程实践

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"Efficient Android Threading - Asynchronous processing techniques.2014" 在移动设备上,尤其是Android系统,高效地处理多线程是优化应用性能的关键。此资源主要探讨了Android平台上异步处理技术,旨在帮助开发者创建响应迅速且性能良好的应用程序。 一、概述 在Android组件和多处理需求部分,作者强调了由于Android应用的特性,如组件化(Activity、Service、ContentProvider和BroadcastReceiver)以及应用执行生命周期,多线程成为必不可少的技术。Android应用运行在Linux进程内,其生命周期直接影响到线程管理。理解这些基础知识能帮助开发者更好地结构化应用程序,提高性能并避免应用卡顿。 二、Java中的多线程基础 这部分详细介绍了Java中的多线程概念。线程是程序执行的基本单元,可以并发运行,从而提高应用程序的效率。然而,多线程也带来了资源消耗增加、复杂性提高以及数据一致性问题。为解决这些问题,开发者需要掌握线程安全,包括Java内置锁(Intrinsic Lock)和监视器(Java Monitor),以及同步共享资源的方法。此外,还讨论了显式锁定机制,并通过消费者-生产者任务示例展示了不同的执行策略。 三、Android上的线程 在Android应用中,线程的使用有所不同,主要有UI线程(主线程)、Binder线程和后台线程。UI线程负责处理用户界面事件,不应执行耗时操作,否则会导致应用无响应(ANR)。Binder线程通常用于跨进程通信。后台线程,如IntentService或自定义线程池,用于执行非UI相关的长时间任务,以保持UI的响应性。了解Linux进程和线程调度优先级对于优化Android应用的性能至关重要。 四、并发执行设计 在这一章,作者可能深入讨论了并发执行的设计模式,如线程池、Handler、AsyncTask等,这些都是Android中实现异步操作的常见工具。线程池可以有效管理大量并发任务,减少线程创建和销毁的开销。Handler和AsyncTask则提供了一种更方便的方式,让开发者在主线程和工作线程之间进行消息传递,确保UI更新的正确性。 总结 此资源全面覆盖了Android平台上的多线程和异步处理技术,对于开发者来说,理解并熟练运用这些知识能够创建出更加高效、响应迅速的应用,提升用户体验。同时,它也提醒开发者注意潜在的性能瓶颈和并发问题,从而避免可能导致应用崩溃或性能下降的错误。
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"Asynchronous Android Programming" English | ISBN: 1785883240 | 2016 | 394 pages About This Book Construct scalable and performant applications to take advantage of multi-thread asynchronous techniques Explore the high-level Android asynchronous constructs available on the Android SDK Choose the most appropriate asynchronous technique to implement your next outstanding feature Who This Book Is For This book is for Android developers who want to learn how to build multithreaded and reliable Android applications using high-level and advanced asynchronous techniques and concepts. What You Will Learn Get familiar with the Android process model and low-level concurrent and multithread constructs available on the Android SDK Use AsyncTask to load data in the background, delivering progress results in the meantime Enhance UI performance and responsiveness by sending work to a service running in the background Defer, schedule, and batch work on the Android system without compromising the battery life and user experience Use the JNI interface to execute concurrent work on native layer Pull and push data from your network servers using the Google GCM platform Create and compose tasks with RxJava to execute complex asynchronous work in a predictable way Get accustomed to the use of the Android Loader construct to deliver up-to-date results In Detail Asynchronous programming has acquired immense importance in Android programming, especially when we want to make use of the number of independent processing units (cores) available on the most recent Android devices. To start with, we will discuss the details of the Android process model and the Java low-level concurrent framework, delivered by the Android SDK. Next, we will discuss the creation of IntentServices, bound services, and external services, which can run in the background even when the user is not interacting with them. In a more advanced phase, you will create background tasks that are able to execute CPU-intensive tasks in native code–making use of the Android NDK. You will be then guided through the process of interacting with remote services asynchronously using the HTTP protocol or Google GCM Platform. Finally, we will introduce RxJava, a popular asynchronous Java framework used to compose work in a concise and reactive way.