Groovy编程入门：Java开发者指南

1星需积分: 9 174 浏览量更新于2024-07-26 2 收藏 5.23MB PDF 举报

"Groovy编程语言入门指南" Groovy是一种基于Java平台的动态脚本语言，设计目的是为了增强Java开发者的生产力。它具有简洁、灵活的语法，并且与Java完全兼容，可以直接调用Java库，使得Java开发者能够快速地编写脚本和应用程序。Groovy结合了面向对象编程（OOP）和函数式编程（FP）的特点，为开发人员提供了丰富的工具和功能。 Groovy编程的特点主要包括以下几个方面： 1. **简洁的语法**：Groovy允许开发者使用更少的代码来完成任务，例如，它可以自动处理方法括号，使得代码看起来更简洁。此外，Groovy支持闭包，这是函数式编程中的一个重要概念，可以用来简化复杂的操作。 2. **动态类型**：Groovy是动态类型的，这意味着在编写代码时，你不需要声明变量的类型。这提高了开发速度，但可能会导致运行时错误，因此需要谨慎使用。 3. **元编程**：Groovy支持元编程，这意味着在运行时可以修改或扩展类的行为。这对于构建框架和工具非常有用，因为它允许动态创建和修改类。 4. **集成Java**：Groovy可以无缝地与Java代码集成，可以直接调用Java类库，Java代码也可以调用Groovy。这对于已经拥有大量Java代码的项目来说是一个巨大的优势。 5. ** Grape**：Grape是Groovy自带的依赖管理工具，类似于Java的Maven或Gradle，它能自动下载和管理Groovy程序所需的依赖库。 6. **Grails**：Groovy也用于构建Web应用，Grails是一个基于Groovy的全栈框架，它简化了Web开发过程，提供了MVC架构和许多内置功能。 7. **GroovyShell和GroovyConsole**：这两个工具是Groovy的开发环境，它们允许开发者直接运行Groovy脚本，测试代码，调试问题，是学习和理解Groovy的好帮手。 8. **GSP（Groovy Server Pages）**：在Web开发中，GSP用于创建动态网页，类似于JSP，但语法更加简洁和灵活。 9. **Spock**：Groovy还有用于编写测试的框架Spock，它提供了一种声明式的测试语法，使得测试代码更易读，更易于维护。 10. **构建工具**：Groovy的Gradle是流行的构建自动化工具，它使用Groovy语言编写构建脚本，相比Ant和Maven，Gradle提供更好的性能和灵活性。 Groovy脚本语言通过其简洁的语法、动态类型和对Java的无缝集成，为Java开发者提供了一个强大而灵活的工具，特别是在脚本编写、自动化任务、Web开发和测试等领域。如果你是一位Java开发者，学习Groovy可以帮助你提高开发效率，拓展编程思维，并更好地利用Java生态系统。

limited functionality set, however, programmers are often given little

support. Fortunately, platform-hosted scripting languages such as Groovy

can help bridge this functionality gap. Th

is is evident with the success of

Groovy and its child—Grails—a versatile model-view-controller (MVC)

Web framework. Sun, too, believes in this alternative way of adding dynam-

icity to applications, by

including a new Java Speciﬁcation Request in Java 6:

the javax.script.* APIs allow seamless embedding of any scripting or

dynamic language into Java applications with a coherent programmin

g API.

Scripting languages have evolved to a point of maturity where they meet

the limitations of the standardized mainstream platforms. When those lan-

guages and platforms come ac

ross, that’s when magic happens, and we can

celebrate a marriage made in Heaven.

Ken Barclay and John Savage are respected teachers and are well posi-

tioned to introduce Groovy to both experienced deve

lopers and novices.

They demonstrate in a clear manner how Groovy augments the Java plat-

form and how to exploit many of its innovative features. The book is easy to

read a

nd not intimidating for those less experienced with programming. It

is a complete exposition of Groovy that addresses all aspects of the pro-

gramming language.

The structure of the book fulﬁlls this aim

by presenting the basics of

Groovy in the early chapters and more advanced concepts in the latter. In

addition, extensive appendices consider more detailed aspects of the lan-

guage.

Deliberately, each chap

ter is relatively small and easy to absorb, yet they

contain a large number of complete code examples, extensive exercises, and

solutions. To illustrate Groovy in application, the book f

eatures a rolling case

study that grows in complexity and sophistication by drawing on the mate-

rials from each preceding chapter. In addition, incremental development

and unit testin

g are central themes in the text and are necessary to suppor t

Groovy’s dynamic nature. The authors also consider Groovy as a multipara-

digm language.

The authors’ own experience suggests that Groovy ha

s a place in the aca-

demic curriculum as well as the experienced developer’s toolbox.

Have a fun time learning Groovy by reading this great book! You won’t

regret it.

Guillaume Laforge

Groovy Project Manager

JSR-241 Speciﬁcation Lead

Foreword xv

Barclay FM.qxd 6/11/06 1:50 PM Page 15

organization

The text is designed to quickly introduce readers to the principal elements

of the Groovy language. It assumes at least a reading knowledge of Java. For

the later chapters, experience with Swing,

Standard Query Language (SQL),

Spring, XML, Ant, and building Web applications would also be useful. The

authors have sought to keep each chapter relatively brief and closely focused.

Some reader

s may wish to dip into an individual chapter to pick out partic-

ular Groovy features. In any event, the shortness of each chapter should

make its contents relatively easy to absorb.

Many chapters are supported by

an appendix to augment the topics cov-

ered. For example, Chapter 7 considers the basics of deﬁning and using

Groovy methods. Appendix G then considers more advanced aspects, such

as overloading and

recursion, which are not central to the main text. Again,

this helps to keep chapters short and targeted.

Most chapters also include many small, self-contained examples to illus-

trate language concepts. They

are complete, and the reader is encouraged to

execute them as part of the learning process. There are also end-of-chapter

exercises, and the reader is encouraged to attempt them. However, both the

chap

ter examples and the solutions to the exercises are available on the

book’ s website.

A feature of the book is a rolling case study concerned with managing

and maintaining a library’s loan stock. At

various points in the text, new

Groovy features are applied to augment the functionality of the case study.

For example, the case study in Chapter 11 exploits methods, closures, and

ﬁles introduc

ed in the preceding chapters.

Chapters 1 to 16 cover the basic features of Groovy. For example, there

are discussions of Groovy methods, closures, lists, and maps as well as

support for classes and inh

eritance.

The important topic of automated unit testing is also addressed.

Groovy’s rapid build-and-run cycle makes it an ideal candidate for develop-

ing unit tests. Groovy exploits the indust

ry standard JUnit framework to

make unit testing both easy and fun. Unit testing used in conjunction with

Groovy combines the ﬂexibility of a dynamically typed language with the

safet

y offered by statically typed languages. To highlight this point, unit test-

ing is an integral part of most of the case studies.

The second part of the book is presented in Chapters 17 to 24, w

here

Groovy is used for more advanced applications. For example, persistence is

imple mented with the Spring framework in conjunction with the

Cloudscape/Derby relational databas

e management system. Groovy also

supports XML and GUI applications through its novel builder notation. We

ﬁnish by considering templates and web applications.

Preface xvii

Barclay FM.qxd 6/11/06 1:50 PM Page 17

conventions

Throughout the book we use an arial typeface to identify Groovy code and

the output from scripts. We also italicize text when introducing a technical

term. The book includes references to websites and to the bibli

ography.

We do not distinguish between a program and a script. Both terms are

used interchangeably. However, we invariably mean a Groovy script.

software distribution

The authors have prepared a supporting web si te—http://www.dcs.

napier.ac.uk/~kab/groovy/groovy.html

—that contains the working scripts

for all of the examples and case studies presented in the book. Answers to

the end-of-chapter exercises are also included.

Groovy is under constant review and is subject to revi

sion. It is the aim

of the authors to use this website to keep the reader informed of signiﬁcant

changes. Therefore, the reader is advised to consult it for up-to-date infor-

mation.

acknowledgments

The authors are deeply grateful to those involved in Groovy’s conception,

the committers that maintain its development, and those instrumental in

the Java Specification Re quest (JSR-241) initiative

(http://www.dcs.

napier.ac.uk/~cs05/groovy/groovy.html

). This book is our contribution to

publicizing the Groovy language. We are indebted to Guillaume Laforge

(Groovy Project Manager) who keeps Groovy “on-track” and to Andrew

Glover (CT

O, Vanward Technologies) for his excellent articles on Groovy on

the IBM Developers website. We are also grateful for the encouragement

and stimulation given by Professor Jon Kerridge (School of Computing,

Napier Univer

sity, Edinburgh) who sent us Groovy challenges that we might

not otherwise have taken up.

The authors also wish to thank Denise Penrose, Tim Cox, Mary James,

Christine Brandt, and their colleagu

es at Morgan Kaufmann, Elsevier for

their help in the production of this book. Finally, we are grateful for the many

helpful suggestions from our reviewers Andrew Glover and Sean Burke. Any

outstanding err

ors in the text are the responsibility of the authors.

xviii Preface

Barclay FM.qxd 6/11/06 1:50 PM Page 18

剩余496页未读，继续阅读

bestree007

粉丝: 7
资源: 10

Groovy编程入门：Java开发者指南

groovy脚本语言bin

java 动态脚本语言 精通 Groovy

groovy 开发入门

Groovy脚本开发

groovy脚本1

基于Java虚拟机的Groovy敏捷开发语言设计源码

Groovy入门经典脚本语言

Java调用Groovy，实时动态加载数据库groovy脚本

groovy脚本执行工具.zip

深入探索Groovy脚本：文件操作的艺术

最新资源

java 动态脚本语言精通 Groovy