1. 前言

在SpringBoot项目中，一般来说是不存在XML配置的，但不是不可以用，而是SpringBoot官方不推荐使用XML配置方式，推荐使用Java来进行配置。我们也可以自己实现一个完全基于Java配置的SS环境。

2.基本SS环境搭建

1. 创建一个普通Maven工程，添加依赖pom.xml文件内容如下

<dependencies>
<!--Spring和SpringMVC依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<!--JSP依赖-->
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.1</version>
</dependency>
<!--JSON依赖-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.45</version>
</dependency>
</dependencies>

1. 创建SpringMVCConfig.java，并继承WebMvcConfigurationSupport类。此类相当于Spring+SpringMVC配置文件

//声明这是一个配置类
@Configuration
//开启注解扫描
@ComponentScan(basePackages = "org.staybug")
public class SpringMVCConfig extends WebMvcConfigurationSupport {
@Override
//配置静态资源过滤
protected void addResourceHandlers(ResourceHandlerRegistry registry) {
//过滤以/js开头的路径,将/**的内容追加到/js/后面得到资源的路径位置
registry.addResourceHandler("/js/**").addResourceLocations("classpath:/js/");
}
@Override
//配置视图解析器
protected void configureViewResolvers(ViewResolverRegistry registry) {
//视图的位置
registry.jsp("/jsp/",".jsp");
}
@Override
//路径映射，访问/hello3,返回hello视图
protected void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/hello3").setViewName("hello");
}
@Override
//配置返回JSON格式数据
protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
FastJsonHttpMessageConverter converter = new FastJsonHttpMessageConverter();
converter.setDefaultCharset(Charset.forName("utf-8"));
FastJsonConfig fastJsonConfig = new FastJsonConfig();
fastJsonConfig.setCharset(Charset.forName("utf-8"));
converter.setFastJsonConfig(fastJsonConfig);
converters.add(converter);
}
}

1. 创建WebInit.java，并实现WebApplicationInitializer.java。此配置类相当于web.xml

public class WebInit implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext acwac = new AnnotationConfigWebApplicationContext();
//加载SpringMVCConfig.java配置文件
acwac.register(SpringMVCConfig.class);
//配置前端控制器
ServletRegistration.Dynamic springmvc = servletContext.addServlet("springmvc", new DispatcherServlet(acwac));
springmvc.setLoadOnStartup(1);
springmvc.addMapping("/");
}
}

1. 创建HelloController.java测试类

@RestController
public class HelloController {
@GetMapping("/hello")
public String hello() {
return "hello";
}
}

1. 测试，访问http://localhost/hello，客户端显示hello