IDEA+Tomcat+Maven+SpringMVC基于Java注解配置web工程

1.在IDEA中新建Maven工程，使用archetype。

2.添加Maven依赖

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.6.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.6.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.1.6.RELEASE</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>

　　目前项目的目录结构如下

　　

3.添加一些文件夹

在main文件夹下新建java和test文件夹，并把java文件夹标记为Sources Root，test文件夹标记为Test Sources Root

标记之后的项目结构如下，熟悉的蓝色和绿色文件夹。

4.开始写SpringMVC基于Java配置的最简代码

建包，Java文件，测试java文件，HTML页面文件如下

下面是代码

package spittr.config;

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

public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[]{RootConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

上面的配置会自动被servlet容器发现，其作用就和web.xml一样的。这是SpringMVC基于Java配置中最有必要理解的一点。

package spittr.config;

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

@Configuration
@EnableWebMvc
@ComponentScan("spittr.web")
public class WebConfig implements WebMvcConfigurer {
    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".html");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }
}

package spittr.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@ComponentScan(basePackages = {"spittr"},
        excludeFilters = {
                @ComponentScan.Filter(type = FilterType.ANNOTATION, value = EnableWebMvc.class)
        })
public class RootConfig {
}

HTML页面非常简易

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Spittr</title>
</head>
<body>
<h1>welcome to spittr</h1>
</body>
</html>

这四个代码就完成了web项目的最简配置

5.配置Tomcat服务器

右上角Edit Configuration...

这两个随便选都行

到此配置结束。运行服务。

出现问题发现页面只显示构建项目时产生的默认jsp文件。这样的话我们把自动生成的jsp和web.xml都删了。反正也用不到了。

整个初始web项目搭建就结束了。

最后看一下TestHelloController的内容。学习一下Spring提供的MVC测试。

import org.junit.Test;
import org.springframework.test.web.servlet.MockMvc;
import spittr.web.HomeController;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.view;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;

public class HomeControllerTest {
    @Test
    public void testHomePage() throws Exception {
        HomeController homeController = new HomeController();
        MockMvc mockMvc = standaloneSetup(homeController).build();
        mockMvc.perform(get("/homepage")).andExpect(view().name("home"));
　　　　 //对controller模拟get请求，并且声明期望的结果是返回名为“home”的视图。
    }
}