spring mvc: 注解和JavaConfig实例

通过javaConfig来配置config，并能正常访问url。

先看图

访问地址：http://localhost:8080/gugua5/

http://localhost:8080/gugua5/helloagain

先看下pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>gugua4</groupId>
  <artifactId>gugua5</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>gugua5 Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <dependencies>

     <!-- spring-test支持 -->
    <dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-test</artifactId>
    	<version>${springVersion}</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!-- spring模块库 -->
    <dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-beans</artifactId>
    	<version>${springVersion}</version>
    </dependency>
    <dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-jdbc</artifactId>
    	<version>${springVersion}</version>
    </dependency>
    <dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-web</artifactId>
    	<version>${springVersion}</version>
    </dependency>
    <dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-webmvc</artifactId>
    	<version>${springVersion}</version>
    </dependency>
    <dependency>
	    <groupId>org.springframework</groupId>
	    <artifactId>spring-expression</artifactId>
	    <version>${springVersion}</version>
	</dependency>

	<!-- (aop)@Aspect注解及代理 -->
	<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
	<dependency>
	    <groupId>org.aspectj</groupId>
	    <artifactId>aspectjweaver</artifactId>
	    <version>1.6.8</version>
	</dependency>
	<!-- https://mvnrepository.com/artifact/cglib/cglib-nodep -->
	<dependency>
	    <groupId>cglib</groupId>
	    <artifactId>cglib-nodep</artifactId>
	    <version>2.1_3</version>
	</dependency>

    <!-- 依赖的持久化类库 -->
    <dependency>
    	<groupId>mysql</groupId>
    	<artifactId>mysql-connector-java</artifactId>
    	<version>5.1.8</version>
    </dependency>
	<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
	<dependency>
	    <groupId>org.springframework</groupId>
	    <artifactId>spring-tx</artifactId>
	    <version>3.0.5.RELEASE</version>
	</dependency>

    <!-- io流/上传类插件 -->
	<!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
	<dependency>
	    <groupId>commons-io</groupId>
	    <artifactId>commons-io</artifactId>
	    <version>2.5</version>
	</dependency>
	<!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
	<dependency>
	    <groupId>commons-fileupload</groupId>
	    <artifactId>commons-fileupload</artifactId>
	    <version>1.3.2</version>
	</dependency>

     <!-- 连接池 -->
    <dependency>
    	<groupId>commons-dbcp</groupId>
    	<artifactId>commons-dbcp</artifactId>
    	<version>${commonsDbcpVersion}</version>
    </dependency>

    <!-- 公共基础类（字符处理，数组，日期，范围） -->
	<dependency>
	    <groupId>org.apache.commons</groupId>
	    <artifactId>commons-lang3</artifactId>
	    <version>3.0</version>
	</dependency>

	 <!-- jsp依赖的web模块库 -->
	 <dependency>
	   <groupId>javax.servlet</groupId>
	   <artifactId>jsp-api</artifactId>
	   <version>2.0</version>
	   <scope>provided</scope>
	</dependency>
	<dependency>
         <groupId>javax.servlet</groupId>
         <artifactId>jstl</artifactId>
         <version>1.2</version>
         <scope>runtime</scope>
    </dependency>
    <dependency>
         <groupId>taglibs</groupId>
         <artifactId>standard</artifactId>
         <version>1.1.2</version>
     </dependency>

    <!-- servlet(HttpServletRequest,HttpServletResponse) -->
    <dependency>
	    <groupId>javax.servlet</groupId>
		<artifactId>javax.servlet-api</artifactId>
		<version>3.1.0</version>
	    <!--
	    <artifactId>servlet-api</artifactId>
	    <version>2.5</version>
	    <scope>provided</scope>
	    -->
	</dependency>

  </dependencies>

  <build>
  <!-- javaConfig配置 -->
  	<pluginManagement>
  		<plugins>
  			<plugin>
  				<groupId>org.apache.maven.plugins</groupId>
  				<artifactId>maven-war-plugin</artifactId>
  				<version>2.6</version>
  				<configuration>
  					<!-- jsp目录 -->
  					<warSourceDirectory>src/main/webapp</warSourceDirectory>
  					<warName>gugua5</warName>
  					<!-- 取消xml配置：web.xml -->
  					<failOnMissingWebXml>false</failOnMissingWebXml>
  				</configuration>
  			</plugin>
  		</plugins>
  	</pluginManagement>
    <finalName>gugua5</finalName>
  </build>

  <properties>
  	<springVersion>4.3.5.RELEASE</springVersion>
  	<mysqlVersion>5.0.11</mysqlVersion>
  	<commonsDbcpVersion>1.4</commonsDbcpVersion>
  	<aspectjweaverVersion>1.8.13</aspectjweaverVersion>
  	<commonsLoggingVersion>1.2</commonsLoggingVersion>
  </properties>

</project>

　　

额外说下,build配置

首先要注意这里maven-war-plugin 插件的声明。正如我们将完全删除web.xml ，我们需要配置这个插件，以避免Maven构建war包失败。第二个变化是加入了JSP/Servlet/Jstl 的依赖关系，这些我们可能需要，因为我们将要使用 servlet API和JSTL视图在我们的代码中.

<build>
  <!-- javaConfig配置 -->
  	<pluginManagement>
  		<plugins>
  			<plugin>
  				<groupId>org.apache.maven.plugins</groupId>
  				<artifactId>maven-war-plugin</artifactId>
  				<version>2.6</version>
  				<configuration>
  					<!-- jsp目录 -->
  					<warSourceDirectory>src/main/webapp</warSourceDirectory>
                                        <!-- 项目名/url -->
  					<warName>gugua5</warName>
  					<!-- 取消xml配置：web.xml/applicationContext.xml/xxx-servlet.xml -->
  					<failOnMissingWebXml>false</failOnMissingWebXml>
  				</configuration>
  			</plugin>
  		</plugins>
  	</pluginManagement>
    <finalName>gugua5</finalName>
  </build>

　　

HelloController.java

package springmvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.ui.ModelMap;

@Controller
@RequestMapping(value="/")
public class HelloWorldController {

	@RequestMapping(method=RequestMethod.GET)
	public String sayHello(ModelMap model)
	{

		model.addAttribute("greeting", "hello world from spring mvc 4");
		return "hello_say";
	}

	@RequestMapping(value="/helloagain", method=RequestMethod.GET)
	public String sayHelloAgain(ModelMap model)
	{
		model.addAttribute("greeting", "hello world again, spring mvc 4");
		return "hello_say";
	}
}

　　

添加配置类
HelloWorldConfiguration.java
在src/main/java下添加下面提到的类指定的包，如下图所示。这种构造类可以被看作是一个替代 spring-servlet.xml，因为它包含了所有必需的组件的扫描和视图解析器的信息。
@Configuration指明该类包含注解为@Bean 生产 bean管理是由Spring容器的一个或多个bean方法。

@EnableWebMvc 等同于 mvc:annotation-driven 在XML中. 它能够为使用@RequestMapping向特定的方法传入的请求映射@Controller-annotated 类。

@ComponentScan 等同于 context:component-scan base-package="..." 提供 spring 在哪里寻找 管理 beans/classes.

package springmvc.configuration;

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.EnableWebMvc;

import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages="springmvc")
public class HelloWorldConfiguration {

	@Bean
	public ViewResolver viewResolver()
	{
		InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
		viewResolver.setViewClass(JstlView.class);
		viewResolver.setPrefix("/WEB-INF/views/");
		viewResolver.setSuffix(".jsp");
		return viewResolver;
	}

}

　　

添加初始化类

添加一个初始化类实现 WebApplicationInitializer 在src/main/java 中使用如下图所示指定包(在这种情况下，作为替代在 web.xml 中定义的任何 Spring 配置)。在Servlet 3.0的容器启动时，这个类将被加载并初始化，并在启动由servlet容器调用方法。

package springmvc.configuration;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class HelloWorldInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

	@Override
	protected Class<?>[] getRootConfigClasses() {
		// TODO Auto-generated method stub
		return new Class[] { HelloWorldConfiguration.class };
	}

	@Override
	protected Class<?>[] getServletConfigClasses() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	protected String[] getServletMappings() {
		// TODO Auto-generated method stub
		return new String [] { "/" };
	}

}

　　

https://www.yiibai.com/spring_mvc/spring-4-mvc-helloworld-tutorial-annotation-javaconfig-full-example.html