《Spring in Action 第三版》英文高清版

5星 · 超过95%的资源需积分: 10 144 浏览量更新于2024-07-25 1 收藏 4.24MB PDF 举报

“Spring in Action 3rd Edition.pdf”是一本关于Spring框架的高清英文版学习书籍，由Craig Walls撰写，属于“Spring in Action”系列。该书涵盖了Spring的核心概念、应用基础以及与其他技术的集成。在书中，作者首先介绍了Spring框架的基础知识，包括其核心模块。Spring的核心模块是整个框架的基础，它提供了依赖注入（Dependency Injection，DI）功能，通过解耦应用程序对象来促进代码的可测试性和可维护性。书中详细讲述了如何使用Spring的bean容器来管理对象的生命周期和相互关系。第二部分涉及Spring应用的基础要素，如与数据库的交互和事务管理。Spring提供了多种方式来操作数据库，例如JDBC模板，使得开发者能更方便地执行SQL语句。同时，Spring的事务管理支持编程式和声明式事务，确保了数据的一致性。在Web应用开发方面，Spring MVC作为Spring框架的一部分，被用于构建高效、可维护的Web应用程序。Spring MVC提供了一种模型-视图-控制器的架构模式，使得开发者可以将业务逻辑、用户界面和数据访问层有效地分离。 Spring Web Flow则是一种处理复杂用户交互流程的工具，允许开发者定义和管理应用中的多步骤工作流。安全是任何应用的重要组成部分，书中也讨论了如何使用Spring Security来保护Spring应用，防止未经授权的访问和攻击。此外，Spring还支持与其他服务的集成，包括远程服务调用、RESTful服务的创建和使用，以及基于JMX的Spring bean管理。Spring的面向切面编程（Aspect-Oriented Programming，AOP）特性允许开发者处理横切关注点，如日志、缓存等，使代码更加整洁。最后，书中还包含了Spring框架的一些边缘话题，如消息传递（Messaging）和一些实用的工具和技巧。《Spring in Action 3rd Edition》是一本全面介绍Spring框架的指南，适合想要深入理解和使用Spring的开发者阅读。通过这本书，读者可以掌握Spring的核心概念，理解如何构建基于Spring的应用，以及如何利用Spring与其他技术和系统的集成来增强应用的功能。

Figure 1.3 Using AOP, systemwide concerns blanket the components that they impact. This

leaves the application components to focus on their specific business functionality.

To demonstrate how aspects can be applied in Spring, let’s revisit the knight

example, adding a basic Spring aspect to the mix.

Anyone who knows anything about knight only knows about knights because their

deeds were chronicled in song by the musically-inclined story tellers known as

minstrels. Let's suppose that we want to record the comings and goings of our

using the services of a minstrel. Listing 1.8 shows the BraveKnight Minstrel

class we might use.

Listing 1.8 A is a musically inclined logging system of medieval times.Minstrel

package com.springinaction.knights;

public class Minstrel {

public void singBeforeQuest() {

System.out.println("Fa la la; The knight is so brave!");

}

public void singAfterQuest() {

System.out.println(

"Tee hee he; The brave knight did embark on a quest!");

}

As you can see, is a rather simple class with two methods. The Minstrel

method is intended to be invoked before a knightsingBeforeQuest()

To be called before

a quest

AOP IN ACTION

Licensed to Mark Wickens <mark@wickensonline.co.uk>

embarks on a quest and the method should be invokedsingAfterQuest()

after the knight has completed a quest. It should be pretty simple to work this into

our code, so let's make the appropriate tweaks to to use the BraveKnight

. Listing 1.9 shows our first attempt.Minstrel

Listing 1.9 The has been modified to call methods before andBraveKnight Minstrel

after embarking on a quest.

package com.springinaction.knights;

public class BraveKnight implements Knight {

private Quest quest;

private Minstrel minstrel;

public BraveKnight(Quest quest, Minstrel minstrel) {

this.quest = quest;

this.minstrel = minstrel;

}

public void embarkOnQuest() throws QuestException {

minstrel.singBeforeQuest();

quest.embark();

minstrel.singAfterQuest();

}

That should do the trick. But something doesn't seem right here. Is it really

within the knight's range of concern to manage his minstrel? It seems to me that a

minstrel should just do its job without the knight asking it to do so. After all, that's

the minstrel's job--to sing about the knight's endeavors. Why should the knight

have to keep reminding the minstrel to do its job?

Furthermore, because the knight needs to know about the minstrel, we're forced

to inject the into the . This not only complicates the Minstrel BraveKnight

's code, but also makes me wonder if we'd ever want a knight whoBraveKnight

didn't have a minstrel. What if the is ? Should we introduceMinstrel null

some -checking logic to cover that case?null

Our simple class is starting to get a bit more complicated andBraveKnight

will become more so if we were to handle the scenario. Butnull Minstrel

using AOP, we can declare that the minstrel should sing about a knight's quests and

free the knight from having to deal with the methods directly.Minstrel

To turn into an aspect, all we need to do is declare it as one in theMinstrel

Spring configuration file. Listing 1.10 shows the updated knights.xml file, updated

to declare as an aspect.Minstrel

Should a knight

manage its own

Minstrel?

Licensed to Mark Wickens <mark@wickensonline.co.uk>

Listing 1.10 Declaring to be an aspect so that the won't haveMinstrel BraveKnight

to keep reminding the to sing.Minstrel

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

<constructor-arg ref="quest" />

</bean>

<bean id="quest"

class="com.springinaction.knights.SlayDragonQuest" />

<bean id="minstrel"

class="com.springinaction.knights.Minstrel" />

<aop:config>

<aop:aspect ref="minstrel">

<aop:pointcut id="embark"

expression="execution(* *.embarkOnQuest(..))" />

<aop:before pointcut-ref="embark"

method="singBeforeQuest"/>

<aop:after pointcut-ref="embark"

method="singAfterQuest"/>

</aop:aspect>

</aop:config>

</beans>

Here I'm using Spring's "aop" configuration namespace to declare that the

bean is an aspect. First, I had to declare the as a bean.Minstrel Minstrel

Then I refer to that bean in the element. Defining the aspect<aop:aspect>

further, I declare (using ) that before the <aop:before> embarkOnQuest()

method is executed, that the 's should beMinstrel singBeforeQuest()

called. This is called . And I (using ) declare that the before advice <aop:after>

method should be called after hassingAfterQuest() embarkOnQuest()

executed. This is known as .after advice

In both cases, the attribute refers to a pointcut namedpointcut-ref

"embark". This pointcut is defined in the preceding element with an<pointcut>

attribute set to select where the advice should be applied. Theexpression

expression syntax is AspectJ's pointcut expression language.

Don't worry if you don't know AspectJ or the details of how AspectJ pointcut

Declare the

Minstrel bean

Define a pointcut

Declare before

advice

Declare after

advice

Licensed to Mark Wickens <mark@wickensonline.co.uk>

expressions are written. We'll talk more about Spring AOP later in chapter 4. For

now it's enough to know that we've asked Spring to call the 's Minstrel

and methods before and after thesingBeforeQuest() singAfterQuest()

embarks on a quest.BraveKnight

That's all there is to it! With a tiny bit of XML, we've just turned Minstrel

into a Spring aspect. Don't worry if this doesn't make complete sense yet--you'll

see plenty more examples of Spring AOP in chapter 4 that should help clear this

up. For now, there are two important points to take away from this example.

First, is still a POJO--there's nothing about it that indicates that it isMinstrel

to be used as an aspect. Instead became an aspect when we declared itMinstrel

as such in the Spring context.

Second, and most important, can be applied to the Minstrel BraveKnight

without the needing to explicitly call on it. In fact, BraveKnight

remains completely unaware of the 's existence.BraveKnight Minstrel

I feel that I should also point out that although I used some Spring magic to turn

into an aspect, it was declared as a Spring first. The pointMinstrel <bean>

here is that you can do anything with Spring aspects that you can do with other

Spring beans, such as injecting them with dependencies.

Using aspects to sing about knights can be a lot of fun. But Spring's AOP can

be used for even more practical things. As you'll see later, Spring AOP can be

employed to provide services such as declarative transactions (chapter 7) and

security (chapter 10).

But for now, let's look at one more way that Spring simplifies Java

development.

Have you ever written some code and then felt like you had already written the

same code before? That's not deja vu, my friend. That's boilerplate code--the code

that you often have to write over and over again to accomplish common and

otherwise simple tasks.

Unfortunately, there are a lot of places where Java APIs involve a lot of

boilerplate code. A common example of boilerplate code can be seen when

working with JDBC to query data from a database. For example, If you've ever

worked with JDBC before, then you've probably written something similar to the

code in listing 1.11.

Listing 1.11 Many Java APIs, such as JDBC, involve writing a lot of boilerplate

1.1.4 Eliminating boilerplate code with templates

Licensed to Mark Wickens <mark@wickensonline.co.uk>

剩余466页未读，继续阅读

codingstyle

粉丝: 102
资源: 71

《Spring in Action 第三版》英文高清版

【Spring in Action 3rd Edition】 pdf

Spring in Action 3rd Edition

Spring.in.Action.3rd.Edition.zip

Manning.Spring.in.Action.3rd.Edition

Spring in Action 3rd Edition Craig Walls

Spring in Action 3rd Edition_spring_action_barnpmd_

spring in action(3rd Edition)

Spring in action 3rd (第三版)

Spring in Action, Third Edition 文字版

spring in action 3Ed 带源代码

最新资源