Build an ebook sharing website on google App Engine Java

Introduction: "Cloud computing" is currently a hot technology direction, this article from Google's cloud computing platform APP Engine, a brief introduction to the Java developers of Google's cloud computing platform. Starting with an actual ebook sharing application, this article describes how to build this application on the Google app Engine platform.

Introduction to the basic concept of "cloud computing"

According to Wikipedia's definition, cloud computing is a dynamically scalable, and often virtualized, resource-computing approach to the Internet, where users don't need to know the details of the cloud, or have expertise in the cloud, or directly control the infrastructure. Cloud computing includes infrastructure-services (IaaS), Platform-Services (PaaS) and software-Services (SaaS), and other technology trends that rely on the Internet to meet customer computing needs. Cloud computing services typically provide common online business applications that are accessed via browsers, and software and data are stored on the server. The introduction of this article is mainly in the "Platform is the service" level. At this level, Google offers the technology that Google App Engine.

Google's "cloud computing" platform

Google, as a search engine, continues to pursue higher scalability and performance during its development, gradually developing a set of good solutions based on free technology, including Google File System, BigTable, and Map Reduce. Based on these technologies, Google has developed a platform called APP Engine that allows developers to develop applications on top of it, while leveraging Google's infrastructure to benefit from non-functional requirements such as scalability, so that it can focus more on addressing business needs.

Google App Engine was first released in April 2008, with the original development language supported by Python. This April, Google App Engine has announced its support for the Java language. The following figure is an overview of Google App Engine for Java support.

Figure 1. Google App Engine for Java Support overview

In WEB application development, Google App Engine supports JSP and Servlet technology; On the data store, Google App Engine supports JDO and JPA two sets of mechanisms, and developers consider data persistence at the object-oriented level without having to consider the number of relationships According to the library. In addition, Google APP Engine also offers a range of commonly used services, such as mail delivery, image processing, and caching.

This article will show you how to build Web applications on the Google App Engine for Java platform with a simple example.