《spring实战第四版》的读书笔记

1 概述

《spring实战第四版》描述了Spring4架构的设计，看完了以后，最大感觉是Spring的IOC与aop理念实在是太强大了，而且用注解来简化系统配置的想法也非常棒，整个架构简直就是MVC的典范

2 Spring之旅

2.1 Intellij IDEA

下载Intellij的15版本，然后将授权地址填写为http://idea.iteblog.com/key.PHP

建立一个Spring项目

按图建立对应的文件

配置启动参数

建立Application的启动项

将入口Class指向到KnightMain

2.2 IOC

12345678package com.fishedee.knights;/** * Created by fishedee on 24/11/2016. */public interface Knight {    void embarkOnQuest();}

建立Kngiht接口

123456789101112131415161718package com.fishedee.knights;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */public class BraveKnight implements Knight{    private Quest quest;    public BraveKnight(Quest quest){        this.quest = quest;    }    public void embarkOnQuest(){        quest.embark();    }}

建立BraveKnight类

12345678package com.fishedee.knights;/** * Created by fishedee on 24/11/2016. */public interface Quest {    public void embark();}

建立Quest接口

12345678910111213141516171819package com.fishedee.knights;import java.io.PrintStream;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */public class SlayDragonQuest implements Quest{    public PrintStream stream;    public SlayDragonQuest(PrintStream stream){        this.stream = stream;    }    public void embark(){        stream.println("Embarking on quest to slay the dragon!");    }}

建立SlayDragonQuest

123456789101112131415package com.fishedee.knights;import org.springframework.context.support.ClassPathXmlApplicationContext;/** * Created by fishedee on 24/11/2016. */public class KnightMain {    public static void main(String[] args) throws Exception{        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("knights.xml");        Knight knight = context.getBean(Knight.class);        knight.embarkOnQuest();        context.close();    }}

建立KnightMain

1234567891011<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">    <bean id="quest" class="com.fishedee.knights.SlayDragonQuest">        <constructor-arg value="#{T(System).out}"/>    </bean>    <bean id="knight" class="com.fishedee.knights.BraveKnight">        <constructor-arg ref="quest"/>    </bean></beans>

建立kngihts.xml的配置文件

运行程序后就能看到Embarking onquest的输出了

在这个程序中可以看到Spring关于ioc的重要特点

• 依赖的对象不直接引用，而是只引用接口
• 对象的创建与注入由Spring来决定，Spring可以根据xml配置来创建对象

这样的ioc就有很特别的能力了

• 依赖解耦，依赖对象只要满足接口就能自由替换，不影响使用方的代码
• 依赖封装，Spring可以在注入对象时，对对象执行变形，例如封装远程调用，mock打桩，进行日志输出等操作

12345678910111213141516171819package com.fishedee.knights;import org.junit.Test;import static org.mockito.Mockito.*;import static org.junit.Assert.*;/** * Created by fishedee on 24/11/2016. */public class BraveKnightTest {    @Test    public void testEmbarkOnQuest() throws Exception {        Quest mockQuest = mock(Quest.class);        BraveKnight knight = new BraveKnight(mockQuest);        knight.embarkOnQuest();        verify(mockQuest,times(1)).embark();    }}

例如，BraveKnight依赖的Quest对象，由于BraveKnight依赖的是接口，不是具体实现，我们就能对Quest进行很容易的mock，从而简单地单元测试

2.3 AOP

1234567891011121314151617181920212223package com.fishedee.knights;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */public class Minstrel {    private PrintStream stream;    public Minstrel(PrintStream stream){        this.stream = stream;    }    public void singBeforeQuest(){        stream.println("Fa la la");    }    public void singAfterQuest(){        stream.println("Tea bee bee");    }}

建立Minstrel类

1234567891011121314151617181920212223242526272829<?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.xsd       http://www.springframework.org/schema/aop       http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">    <bean id="quest" class="com.fishedee.knights.SlayDragonQuest">        <constructor-arg value="#{T(System).out}"/>    </bean>    <bean id="knight" class="com.fishedee.knights.BraveKnight">        <constructor-arg ref="quest"/>    </bean>    <bean id="minstrel" class="com.fishedee.knights.Minstrel">        <constructor-arg value="#{T(System).out}"/>    </bean>    <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>

启动后看到Embark前后执行对对应的输出

修改配置文件，将Minstrel声明为切面，当调用embarkOnQuest方法时会自动回调Minstrel的方法

就这样，Spring在不修改Knight与Quest的代码下，就能在其方法执行前后插入自己想要的代码，这让我们能达成简单的cache，日志，事务等切面式的实现了

3 基础ioc

Spring中提供三种装配bean的方法

• 在xml中进行显式配置
• 在Java中进行显式配置
• 隐式的bean发现机制和自动装配

3.1 在xml中装配

第2章已经写过，就不多说了

3.2 在java中装配

1234567891011121314151617181920package com.fishedee.knights;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;/** * Created by fishedee on 26/11/2016. */@Configurationpublic class Config {    @Bean    public Quest quest(){        return new SlayDragonQuest();    }    @Bean    public Knight knight(Quest quest){        return new BraveKnight(quest);    }}

代替xml，使用Java文件来做配置，要注意用Configuration声明配置文件，生成bean的方法都用Bean注解

12345678910111213141516package com.fishedee.knights;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;/** * Created by fishedee on 24/11/2016. */public class KnightMain {    public static void main(String[] args) throws Exception{        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Config.class);        Knight knight = context.getBean(Knight.class);        knight.embarkOnQuest();        context.close();    }}

启动ApplicationContext改用AnnotationConfigApplicationContext即可

使用Java装配的好处是，强类型，支持丰富的java语法特性

3.3 自动装配

12345678910111213141516171819202122package com.fishedee.knights;import org.springframework.stereotype.Component;import java.io.PrintStream;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Componentpublic class SlayDragonQuest implements Quest{    public PrintStream stream;    public SlayDragonQuest(){        this.stream = System.out;    }    public void embark(){        stream.println("Embarking on quest to slay the dragon!");    }}

将SlayDragonQuest声明为bean，加入@Component即可

123456789101112131415161718192021package com.fishedee.knights;import org.springframework.stereotype.Component;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Componentpublic class BraveKnight implements Knight{    private Quest quest;    public BraveKnight(Quest quest){        this.quest = quest;    }    public void embarkOnQuest(){        quest.embark();    }}

将BraveKnight声明为bean，同时Quest出现在构造参数上，这个Quest类型会被自动装配

1234567891011121314151617181920212223package com.fishedee.knights;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Componentpublic class BraveKnight implements Knight{    @Autowired    private Quest quest;    public BraveKnight(){    }    public void embarkOnQuest(){        quest.embark();    }}

或者可以将Quest写上Autowired注解，这个私有变量也会被自动装配

12345678910111213141516171819202122232425package com.fishedee.knights;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import static org.mockito.Mockito.*;import static org.junit.Assert.*;/** * Created by fishedee on 24/11/2016. */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes = Config.class)public class BraveKnightTest {    @Autowired    BraveKnight knight;    @Test    public void testEmbarkOnQuest() throws Exception {        knight.embarkOnQuest();    }}

自动装配也支持单元测试，注意测试文件中指定Config

123456789101112131415161718192021222324<?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"       xmlns:context="http://www.springframework.org/schema/context"       xsi:schemaLocation="http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans.xsd       http://www.springframework.org/schema/aop       http://www.springframework.org/schema/aop/spring-aop-4.1.xsd       http://www.springframework.org/schema/context       http://www.springframework.org/schema/context/spring-context-4.1.xsd">    <context:component-scan base-package="com.fishedee.knights"/>    <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>

在xml配置文件中加入component-scan，并指定包名即可

12345678910111213package com.fishedee.knights;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;/** * Created by fishedee on 26/11/2016. */@Configuration@ComponentScanpublic class Config {}

或在Java配置中，加入ComponentScan注解即可，非常简单

自动装配能大幅度减少需要配置的bean，所以使用中一般是自动装配为主，Java装配为辅的方式

3.4 混合配置

12345678910111213package com.fishedee.knights;import org.springframework.context.annotation.*;/** * Created by fishedee on 26/11/2016. */@Configuration@ComponentScan@Import(Config2.class)@ImportResource("knights.xml")public class Config {}

Java配置中引入其他Java配置，或者引入其他xml配置的方法

12345678910111213<?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"       xmlns:context="http://www.springframework.org/schema/context"       xsi:schemaLocation="http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans.xsd       http://www.springframework.org/schema/aop       http://www.springframework.org/schema/aop/spring-aop-4.1.xsd       http://www.springframework.org/schema/context       http://www.springframework.org/schema/context/spring-context-4.1.xsd">    <import resource="knights2.xml"/></beans>

xml配置中引入其他xml配置的方式，注意，不能用xml引入Java配置

4 高级ioc

4.1 环境装配

12345678910111213141516171819202122232425package com.fishedee.knights;import org.springframework.context.annotation.*;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */@Configuration@ComponentScanpublic class Config {    @Bean    @Profile("dev")    public PrintStream printStream(){        return System.out;    }    @Bean    @Profile("prod")    public PrintStream printStream2()throws Exception{        return new PrintStream("fish.out");    }}

可以在Config上加入Profile注解，用来表明这个bean配置是在哪个环境上使用的，当然也可以将Profile注解放到Config上，表明这个Config都是Profile指定的

123456789101112131415161718192021package com.fishedee.knights;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import org.springframework.core.env.ConfigurableEnvironment;/** * Created by fishedee on 24/11/2016. */public class KnightMain {    public static void main(String[] args) throws Exception{        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();        context.getEnvironment().setActiveProfiles("prod");        context.register(Config.class);        context.refresh();        //ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("knights.xml");        Knight knight = context.getBean(Knight.class);        knight.embarkOnQuest();        context.close();    }}

启动时可以根据context来指定profile

123456789101112131415161718192021222324252627package com.fishedee.knights;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ActiveProfiles;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import static org.mockito.Mockito.*;import static org.junit.Assert.*;/** * Created by fishedee on 24/11/2016. */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes = Config.class)@ActiveProfiles("dev")public class BraveKnightTest {    @Autowired    BraveKnight knight;    @Test    public void testEmbarkOnQuest() throws Exception {        knight.embarkOnQuest();    }}

单元测试中可以根据ActiveProfiles注解来指定环境

4.2 条件装配

12345678910111213141516171819202122232425package com.fishedee.knights;import org.springframework.context.annotation.*;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */@Configuration@ComponentScanpublic class Config {    @Bean    @Conditional(ConfigCondition.class)    public PrintStream printStream(){        return System.out;    }    @Bean    @Profile("prod")    public PrintStream printStream2()throws Exception{        return new PrintStream("fish.out");    }}

指定printStream生成condition为ConfigCondition.class

1234567891011121314151617181920package com.fishedee.knights;import org.springframework.context.annotation.Condition;import org.springframework.context.annotation.ConditionContext;import org.springframework.core.type.AnnotatedTypeMetadata;/** * Created by fishedee on 27/11/2016. */public class ConfigCondition implements Condition{    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata){        String[] profiles = context.getEnvironment().getActiveProfiles();        for( String single : profiles ){            if( single.equals("fish")){                return true;            }        }        return false;    }}

而ConfigCondition则是检查profile是否为fish

所以，条件装配是比环境装配更为强大而动态的方式而已。

4.3 指定装配

1No qualifying bean of type 'com.fishedee.knights.Quest' available: expected single matching bean but found 2: slayDragonQuest,slayHumanQuest

如果我有两个Quest都满足Quest接口时，Spring就会弹出错误，说有歧义，slayDragonQuest和slayHumanQuest

123456789101112131415161718192021222324package com.fishedee.knights;import org.springframework.context.annotation.Primary;import org.springframework.stereotype.Component;import java.io.PrintStream;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Component@Primarypublic class SlayDragonQuest implements Quest{    public PrintStream stream;    public SlayDragonQuest(PrintStream stream){        this.stream = stream;    }    public void embark(){        stream.println("Embarking on quest to slay the dragon!");    }}

解决办法一，给SlayDragonQuest给予Primary优先级，默认选择它

1234567891011121314151617181920212223242526package com.fishedee.knights;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.stereotype.Component;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Componentpublic class BraveKnight implements Knight{    @Autowired    @Qualifier("slayDragonQuest")    private Quest quest;    public BraveKnight(){    }    public void embarkOnQuest(){        quest.embark();    }}

解决办法二，让Knight指定哪个Quest，用Qualifier注解

4.4 作用域

Spring创建的bean，有以下几种作用域

• 单例(Singleton)，整个应用只有一个bean实例
• 原型(Prototype)，每次都创建一个bean实例
• 会话(Session)，在Web中，每个会话创建一个bean实例
• 请求(Request)，在Web中，每个请求创建一个bean实例

默认情况下，所有的bean都是单例会话域

123456789101112131415161718192021222324252627282930313233package com.fishedee.knights;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.beans.factory.config.ConfigurableBeanFactory;import org.springframework.context.annotation.Scope;import org.springframework.context.annotation.ScopedProxyMode;import org.springframework.stereotype.Component;import java.util.Queue;/** * Created by fishedee on 24/11/2016. */@Component@Scope(        value=ConfigurableBeanFactory.SCOPE_PROTOTYPE,        proxyMode = ScopedProxyMode.INTERFACES)public class BraveKnight implements Knight{    @Autowired    @Qualifier("slayDragonQuest")    private Quest quest;    public BraveKnight(){    }    public void embarkOnQuest(){        quest.embark();    }}

在bean中使用Scope注解就可以了，注意多例插入到单例对象中，需要用INTERFACES的proxy

5 aop

5.1 基础切面

在Spring中，切面有以下的几种

• After，在目标方法返回或抛出异常后调用
• AfterReturning，在目标方法返回后调用
• AfterThrowing，在目标方法抛出异常后调用
• Before，在目标方法调用之前调用
• Around，将目标方法封装起来

123456789101112131415161718192021222324252627282930313233343536package com.fishedee.knights;import org.aspectj.lang.annotation.After;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.aspectj.lang.annotation.Pointcut;import org.springframework.stereotype.Component;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */@Component@Aspectpublic class Minstrel {    private PrintStream stream;    public Minstrel(){        stream = System.out;    }    @Pointcut("execution(* *.embarkOnQuest(..))")    public void quest(){}    @Before("quest()")    public void singBeforeQuest(){        stream.println("Fa la la");    }    @After("quest()")    public void singAfterQuest(){        stream.println("Tea bee bee");    }}

将Minstrel方法用Aspect注解圈起来，然后在触发方法上，加入Pointcut,Before,After等触发类型即可

123456789101112131415161718package com.fishedee.knights;import org.springframework.context.annotation.*;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */@Configuration@EnableAspectJAutoProxy@ComponentScanpublic class Config {    @Bean    public PrintStream printStream(){        return System.out;    }}

配置上开启EnableAspectJAutoProxy注解

5.2 切面参数

1234567891011121314151617181920212223242526272829303132333435package com.fishedee.knights;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.*;import org.springframework.stereotype.Component;import java.io.PrintStream;/** * Created by fishedee on 26/11/2016. */@Component@Aspectpublic class Minstrel {    private PrintStream stream;    public Minstrel(){        stream = System.out;    }    @Pointcut("execution(* *.embark(int)) && args(embarkPower)")    public void quest(int embarkPower){}    @Around("quest(embarkPower2)")    public void aroundQuest(ProceedingJoinPoint jp,int embarkPower2)throws Throwable{        try {            stream.println("Fa la la");            stream.println("Power "+embarkPower2);            jp.proceed();        }finally{            stream.println("Tea bee bee");        }    }}

在Pointcut中指定包含参数的函数类型，以及args指定参数名称，然后在Around上也指定接收参数即可。注意，在Around上要调用原函数。

6 基础MVC

6.1 Intellij IDEA

创建一个勾选了MVC选项的Spring项目

建立以上的文件和文件夹

123456<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"         version="3.1"></web-app>

web.xml为空

12345678910111213141516<%--  Created by IntelliJ IDEA.  User: fishedee  Date: 28/11/2016  Time: 9:11 PM  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html>  <head>    <title>Spring MVC</title>  </head>  <body>    Hello World  </body></html>

home.jsp为简单的jsp文件

123456789101112131415161718192021222324package com.fishedee;import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;/** * Created by fishedee on 29/11/2016. */public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {    @Override    protected String[] getServletMappings(){        System.out.println("uu");        return new String[]{"/"};    }    @Override    protected Class<?>[] getRootConfigClasses(){        return new Class<?>[]{RootConfig.class};    }    @Override    protected Class<?>[] getServletConfigClasses(){        return new Class<?>[]{WebConfig.class};    }}

WebAppInitializer为入口的serlet文件，getRootConfigClasses指向通用bean的配置文件，getServletConfigClasses指向mvc使用的bean的配置文件

12345678910111213141516171819package com.fishedee;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.ViewResolver;import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.servlet.view.InternalResourceViewResolver;/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvcpublic class RootConfig {}

RootConfig基本为空

1234567891011121314151617181920212223242526272829303132package com.fishedee;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.ViewResolver;import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.servlet.view.InternalResourceViewResolver;/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvc@ComponentScanpublic class WebConfig extends WebMvcConfigurerAdapter {    @Bean    public ViewResolver viewResolver(){        InternalResourceViewResolver resolver = new InternalResourceViewResolver();        resolver.setPrefix("/WEB-INF/views/");        resolver.setSuffix(".jsp");        resolver.setExposeContextBeansAsAttributes(true);        return resolver;    }    @Override    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){        configurer.enable();    }}

WebConfig配置了视图解析器，还有默认的路由处理

1234567891011121314151617package com.fishedee;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;/** * Created by fishedee on 29/11/2016. */@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        return "home";    }}

HomeController的代码

增加tomcat的启动选项

让server指向到tomcat的安装目录就可以了，注意tomcat必须是7以上的版本

项目依赖中加入tomcat安装目录中lib文件的servlet-api.jar文件

打包选项中将Spring依赖都打包进去就可以了

最后，就是启动服务器了，这时，你应该看到Hello World的输出了

6.2 控制器

1234567891011/** * Created by fishedee on 29/11/2016. */@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        return "home";    }}

简单的controller，返回值是视图的名称

12345678910111213141516171819package com.fishedee;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.ui.Model;/** * Created by fishedee on 29/11/2016. */@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(Model model){        model.addAttribute("text","Hello Fish");        return "home";    }}

新增Model参数，将视图的数据写入到Model中

12345678910<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html>  <head>    <title>Spring MVC</title>  </head>  <body>    <c:out value="${text}"/>  </body></html>

home.jsp加入taglib，用c:out标签输出text参数

加入jstl与taglibs两个库

启动后就能看到带参数的视图了

6.3 输入

123456789101112@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(            @RequestParam("page") int page,            @RequestParam(value="page2",defaultValue = "mmc") String page2,            Model model){        model.addAttribute("text","Hello Fish "+ page+","+page2);        return "home";    }}

控制器中处理Query的参数，用RequestParam就可以了

1234567891011@Controllerpublic class HomeController {    @RequestMapping(value="/{spittleId}",method= RequestMethod.GET)    public String home(            @PathVariable("spittleId") int spittleId,            Model model){        model.addAttribute("text","Hello Fish "+ spittleId);        return "home";    }}

控制器中处理Path的参数，用PathVariable就可以了

6.4 表单

1234567891011121314<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html>  <head>    <title>Spring MVC</title>  </head>  <body>    <form method="post">      FirstName: <input type="text" name="firstName"/><br/>      LastName: <input type="text" name="lastName"/><br/>      <input type="submit" value="提交"/>      </form>  </body></html>

提交的表单

123456789101112131415@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        return "home";    }    @RequestMapping(value="/",method= RequestMethod.POST)    public String submit(            User user){        System.out.println(user.getFirstName()+","+user.getLastName());        return "home";    }}

添加控制器，将表单参数写入到来自一个实体对象

1234567891011121314151617181920212223242526/** * Created by fishedee on 15/12/2016. */public class User {    private String firstName;    public void setFirstName(String firstName) {        this.firstName = firstName;    }    public String getFirstName() {        return firstName;    }    private String lastName;    public void setLastName(String lastName) {        this.lastName = lastName;    }    public String getLastName() {        return lastName;    }}

建立User对象即可

6.5 异常

12345678910@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        throw new MyException();        //return "home";    }}

在Controller上抛出指定的异常

123456789101112package com.fishedee;import org.springframework.http.HttpStatus;import org.springframework.web.bind.annotation.ResponseStatus;/** * Created by fishedee on 15/12/2016. */@ResponseStatus(value= HttpStatus.NOT_FOUND,reason = "找不到呀")public class MyException extends RuntimeException {}

如果异常上有ResponseStatus的标志，那么mvc的返回码就会按照注解上的显示

123456789101112131415@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        throw new RuntimeException("mm");        //return "home";    }    @ExceptionHandler(Exception.class)    public String handleException(Model model){        model.addAttribute("text","这里是异常呀");        return "home";    }}

通过在Controller类方法上增加ExceptionHandler来捕捉通用异常，并用特定的view来渲染错误

123456789@ControllerAdvicepublic class MyHandler {    @ExceptionHandler(Exception.class)    public String handleException(Model model){        model.addAttribute("text","这里是异常呀2");        return "home";    }}

新增ControllerAdvice捕捉所有Controller的异常

7 MVC的View

7.1 通用视图解析器

1234567891011121314151617181920212223242526272829303132333435package com.fishedee;import org.springframework.web.servlet.View;import org.springframework.web.servlet.ViewResolver;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.OutputStream;import java.util.Locale;import java.util.Map;/** * Created by fishedee on 15/12/2016. */public class MyViewResolver implements ViewResolver{    @Override    public View resolveViewName(String var1, Locale var2) throws Exception{        return new MyView();    }}class MyView implements View{    @Override    public String getContentType(){        return "text/html;charset=utf-8";    }    @Override    public void render(Map<String,?> model, HttpServletRequest request, HttpServletResponse response)throws Exception{        OutputStream outputStream = response.getOutputStream();        String data = "<!doctype><html><head></head><body>jj</body></html>";        response.addHeader("Content-Type","text/html;charset=utf-8");        outputStream.write(data.getBytes("UTF-8"));    }}

定义属于自己的ViewResolver，相当的简单

1234567891011121314151617/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvc@ComponentScanpublic class WebConfig extends WebMvcConfigurerAdapter {    @Bean    public ViewResolver viewResolver(){        return new MyViewResolver();    }    @Override    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){        configurer.enable();    }}

然后在WebConfig中将ViewResolver指向到自己的MyViewResolver即可

7.2 Thymeleaf解析器

加入thymeleaf的依赖

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849package com.fishedee;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.ViewResolver;import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.thymeleaf.spring4.SpringTemplateEngine;import org.thymeleaf.spring4.view.ThymeleafViewResolver;import org.thymeleaf.templateresolver.ServletContextTemplateResolver;import org.thymeleaf.templateresolver.TemplateResolver;/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvc@ComponentScanpublic class WebConfig extends WebMvcConfigurerAdapter {    @Bean    public ViewResolver viewResolver(SpringTemplateEngine engine){        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();        viewResolver.setTemplateEngine(engine);        return viewResolver;    }    @Bean    public SpringTemplateEngine templateEngine(TemplateResolver resolver){        SpringTemplateEngine templateEngine = new SpringTemplateEngine();        templateEngine.setTemplateResolver(resolver);        return templateEngine;    }    @Bean    public TemplateResolver templateResolver(){        TemplateResolver templateResolver = new ServletContextTemplateResolver();        templateResolver.setPrefix("/WEB-INF/views/");        templateResolver.setSuffix(".html");        templateResolver.setTemplateMode("HTML5");        return templateResolver;    }    @Override    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){        configurer.enable();    }}

将ViewResolver指向ThymeleafViewResolver

123456789101112<html    xmlns="http://www.w3.org/1999/xhtml"    xmlns:th="http://www.thymeleaf.org"><head>    <meta charset="UTF-8"/>    <title>Title</title></head><body>    <h1>Welcome!</h1>    <div th:text="${text}"></div></body></html>

建立一个Thymeleaf的模板，呃，明显比用标签变量的jsp要顺眼多了

8 MVC的安全

8.1 基础

引入security-web与security-config两个依赖

12345678910package com.fishedee;import org.springframework.core.annotation.Order;import org.springframework.security.web.context.AbstractSecurityWebApplicationInitializer;/** * Created by fishedee on 15/12/2016. */public class SecurityAppInitializer extends AbstractSecurityWebApplicationInitializer{}

建立AbstractSecurityWebApplicationInitializer类，其会增加Security的Filter

12345678910111213141516171819202122package com.fishedee;import org.springframework.context.annotation.Configuration;import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;import org.springframework.security.config.annotation.web.builders.HttpSecurity;import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;/** * Created by fishedee on 15/12/2016. */@Configuration@EnableWebSecuritypublic class SecurityConfig extends WebSecurityConfigurerAdapter{    @Override    protected void configure(HttpSecurity http) throws Exception {        http.authorizeRequests().anyRequest().denyAll();        http.csrf().disable();    }}

建立SecurityConfig，建立安全配置，默认为禁止所有的请求访问

1234567891011121314151617181920/** * Created by fishedee on 29/11/2016. */public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {    @Override    protected String[] getServletMappings(){        System.out.println("uu");        return new String[]{"/"};    }    @Override    protected Class<?>[] getRootConfigClasses(){        return new Class<?>[]{RootConfig.class,SecurityConfig.class};    }    @Override    protected Class<?>[] getServletConfigClasses(){        return new Class<?>[]{WebConfig.class};    }}

在WebAppInitializer中将SecurityConfig.class加入到RootConfig中

这时候无论打开什么请求都会返回403返回了

8.2 身份认证

123456789101112131415161718@Configuration@EnableWebSecuritypublic class SecurityConfig extends WebSecurityConfigurerAdapter{    @Override    protected void configure(AuthenticationManagerBuilder auth)throws Exception{        auth.inMemoryAuthentication()                .withUser("fish").password("123").roles("USER","ADMIN").and()                .withUser("fish2").password("456").roles("USER");    }    @Override    protected void configure(HttpSecurity http) throws Exception {        http.authorizeRequests().                anyRequest().authenticated().and().formLogin();        http.csrf().disable();    }}

配置为所有请求都必须登录后才能访问

这时候请求所有请求都会跳转到固定的/login页面，登录后自动跳转到原有的请求页面，注意，security指定的登出为/logout

8.3 获取用户

1234567891011121314@Controllerpublic class HomeController {    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(Model model){        model.addAttribute("text","My Name is Fish");        UserDetails userDetails = (UserDetails) SecurityContextHolder.getContext()                .getAuthentication()                .getPrincipal();        System.out.println(userDetails);        return "home";    }}

在Controller层通过SecurityContextHolder.getContext获取当前用户的信息

9 数据库

9.1 数据源

引入MySQL-connector-java的库

12345678910111213141516/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvcpublic class RootConfig {    @Bean    public DataSource dataSource(){        DriverManagerDataSource ds = new DriverManagerDataSource();        ds.setDriverClassName("com.mysql.jdbc.Driver");        ds.setUrl("jdbc:mysql://localhost:3306/test");        ds.setUsername("root");        ds.setPassword("1");        return ds;    }}

RootConfig 中加入DataSource的配置，这里使用的是Spring的jdbc连接控制器

9.2 jdbc模板

123456789101112131415161718192021/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvcpublic class RootConfig {    @Bean    public DataSource dataSource(){        DriverManagerDataSource ds = new DriverManagerDataSource();        ds.setDriverClassName("com.mysql.jdbc.Driver");        ds.setUrl("jdbc:mysql://localhost:3306/test");        ds.setUsername("root");        ds.setPassword("1");        return ds;    }    @Bean    public JdbcOperations jdbcTemplate(DataSource ds){        return new JdbcTemplate(ds);    }}

RootConfig中加入jdbcTemplate

123456789101112131415161718@Repositorypublic class UserRepositoryImpl implements UserRepository{    @Autowired    private JdbcOperations jdbcOperations;    public List<User> findAll(){        return jdbcOperations.query("select * from t_user", new RowMapper<User>() {            @Override            public User mapRow(ResultSet resultSet, int i) throws SQLException {                return new User(                        resultSet.getInt("userId"),                        resultSet.getString("name"),                        resultSet.getString("email")                );            }        });    }}

在UserRepositoryImpl中使用jdbcOperations来获取数据，简单暴力

1234567/** * Created by fishedee on 16/12/2016. */public interface UserRepository {    List<User> findAll();}

简单的UserRepository接口

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748package com.fishedee;/** * Created by fishedee on 16/12/2016. */public class User {    public User(){    }    public User(int userId,String name,String mail){        this.userId = userId;        this.name = name;        this.mail = mail;    }    private int userId;    public int getUserId(){        return this.userId;    }    public void setUserId(int userId){        this.userId = userId;    }    private String name;    public String getName(){        return this.name;    }    public void setName(String name){        this.name = name;    }    private String mail;    public String getMail(){        return this.mail;    }    public void setMail(String mail){        this.mail = mail;    }}

无聊的User类

12345678910111213141516@Controllerpublic class HomeController {    @Autowired    private UserRepository userRepository;    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        List<User> users = userRepository.findAll();        for( User user : users ){            System.out.println(user.getName()+","+user.getMail());        }        return "home";    }}

在HomeController中引入UserRepository，然后直接使用就可以了

10 缓存

10.1 缓存源

123456789101112131415161718192021222324@Configuration@EnableWebMvc@EnableCachingpublic class RootConfig {    @Bean    public CacheManager cacheManager(){        return new ConcurrentMapCacheManager();    }    @Bean    public DataSource dataSource(){        DriverManagerDataSource ds = new DriverManagerDataSource();        ds.setDriverClassName("com.mysql.jdbc.Driver");        ds.setUrl("jdbc:mysql://localhost:3306/test");        ds.setUsername("root");        ds.setPassword("1");        return ds;    }    @Bean    public JdbcOperations jdbcTemplate(DataSource ds){        return new JdbcTemplate(ds);    }}

配置好CacheManager的bean，并且设置好EnableCaching的注解即可

10.2 方法注解

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657@Repositorypublic class UserRepositoryImpl implements UserRepository{    @Autowired    private JdbcOperations jdbcOperations;    public List<User> findAll(){        return jdbcOperations.query("select * from t_user", new RowMapper<User>() {            @Override            public User mapRow(ResultSet resultSet, int i) throws SQLException {                return new User(                        resultSet.getInt("userId"),                        resultSet.getString("name"),                        resultSet.getString("email")                );            }        });    }    @Cacheable(value="mycache",key="#id")    public User get(int id){        System.out.println("repository get");        return jdbcOperations.queryForObject("select * from t_user where userId = ?", new RowMapper<User>() {            @Override            public User mapRow(ResultSet resultSet, int i) throws SQLException {                return new User(                        resultSet.getInt("userId"),                        resultSet.getString("name"),                        resultSet.getString("email")                );            }        },id);    }    @CacheEvict(key="#id",value="mycache")    public void del(int id){        System.out.println("repository del");        jdbcOperations.update("delete from t_user where userId = ?",id);    }    @CachePut(key="#result.userId",value="mycache")    public User add(final User user){        System.out.println("repository add");        KeyHolder keyHolder = new GeneratedKeyHolder();        jdbcOperations.update(new PreparedStatementCreator(){            public PreparedStatement createPreparedStatement(Connection conn)                    throws SQLException {                PreparedStatement ps = conn.prepareStatement("insert into t_user(name,email)value(?,?)", Statement.RETURN_GENERATED_KEYS) ;                ps.setString(1,user.getName());                ps.setString(2,user.getMail());                return ps ;            }        },keyHolder);        user.setUserId(keyHolder.getKey().intValue());        return user;    }}

UserRepositoryImpl在方法中加入Cacheable注解（方法调用缓存），CacheEvict注解（方法调用完毕后删除缓存），CachePut注解（方法调用完毕后增加缓存），注意缓存的key必须为同一个数据类型

12345678910111213141516171819202122@Controllerpublic class HomeController {    @Autowired    private UserRepository userRepository;    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        System.out.println("begin");        userRepository.get(1);        userRepository.get(1);        System.out.println("get finish");        User newUser = userRepository.add(new User(0,"mm3","[e-mail]"));        userRepository.get(newUser.getUserId());        System.out.println("add finish");        userRepository.del(1);        userRepository.get(1);        System.out.println("del finish");        return "home";    }}

在HomeController中测试缓存的使用

1234567beginrepository getget finishrepository addadd finishrepository delrepository get

注意到了第二次get被缓存了，同时add以后也会走缓存了，而del以后也会强制走缓存了

11 消息

11.1 消息源

安装activemq，注意用bin/macos下的activemq来启动，能进入到管理员页面才算成功

引入activemq-spring的包，以及jackjson的三个包

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657package com.fishedee;import org.apache.activemq.ActiveMQConnectionFactory;import org.springframework.cache.annotation.EnableCaching;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.jms.annotation.EnableJms;import org.springframework.jms.config.DefaultJmsListenerContainerFactory;import org.springframework.jms.core.JmsTemplate;import org.springframework.jms.support.converter.MappingJackson2MessageConverter;import org.springframework.jms.support.converter.MarshallingMessageConverter;import org.springframework.jms.support.converter.MessageConverter;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import javax.jms.ConnectionFactory;/** * Created by fishedee on 29/11/2016. */@Configuration@EnableWebMvc@EnableJms@ComponentScanpublic class RootConfig {    @Bean    public ConnectionFactory connectionFactory(){        ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();        connectionFactory.setBrokerURL("tcp://localhost:61616");        return connectionFactory;    }    @Bean    public MessageConverter messageConverter(){        MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();        converter.setTypeIdPropertyName("_type");        return converter;    }    @Bean    public JmsTemplate jmsTemplate(ConnectionFactory factory,MessageConverter messageConverter){        JmsTemplate template = new JmsTemplate();        template.setConnectionFactory(factory);        template.setMessageConverter(messageConverter);        return template;    }    @Bean    public DefaultJmsListenerContainerFactory jmsListenerContainerFactory(ConnectionFactory factory2,MessageConverter messageConverter) {        DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();        factory.setConnectionFactory(factory2);        factory.setMessageConverter(messageConverter);        factory.setConcurrency("1-1");        return factory;    }}

在RootConfig中配置ConnectionFactory，JmsTemplate和DefaultJmsListenerContainerFactory，分别代表连接池，发送模板，接收池，最后，注意打开EnableJms注解，还有就是jackjson要配置TypeIdPropertyName

11.2 发布消息

12345678910111213@Controllerpublic class HomeController {    @Autowired    JmsTemplate jmsTemplate;    @RequestMapping(value="/",method= RequestMethod.GET)    public String home(){        jmsTemplate.convertAndSend("myqueue",new User(1001,"fish","fish2"));        return "home";    }}

直接用convertAndSend发送消息，简单暴力

11.3 接收消息

1234567@Componentpublic class MessageReceiver {    @JmsListener(destination = "myqueue")    public void receiveMessage(final User user) {        System.out.println(user);    }}

使用JmsListener注解来接收消息，依然也是简单暴力

12 总结

Spring的IOP与AOP，配合Java中的注解，开发后台相当的轻松简单，唯一不爽的地方是

• 引入外部依赖库因为墙的缘故很慢
• 配置太过麻烦，每次都要调好久
• 与Servlet的耦合太紧密了，不能独自启动后台

总体来说，整个设计还是非常值得参考的

from: http://fishedee.com/%E5%90%8E%E7%AB%AF/2016/11/22/Spring%E5%AE%9E%E6%88%98%E7%AC%AC%E5%9B%9B%E7%89%88-%E7%9A%84%E8%AF%BB%E4%B9%A6%E7%AC%94%E8%AE%B0.html