springmvc 注解配置（方法一）

1.spring-webmvc依赖

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc</artifactId>
  <version>5.0.5.RELEASE</version>
</dependency>

2.新建一个webmvc配置类，实现WebMvcConfigurer

@Configuration
@EnableWebMvc
@ComponentScan
public class WebConfig1 implements WebMvcConfigurer {
//配置视图解析器
    @Bean
    public ViewResolver viewResolver(){
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setPrefix("/WEB-INF/jsp/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }
}

3.新建一个webapp初始化类，实现WebApplicationInitializer

public class WebAppInit implements WebApplicationInitializer {
    @Override
    public void onStartup(javax.servlet.ServletContext servletContext) throws ServletException {
        // Load Spring web application configuration
        AnnotationConfigWebApplicationContext ac = new AnnotationConfigWebApplicationContext();
        ac.register(WebConfig1.class);
       // ac.refresh();此处应该注释，否则报错

        // Create and register the DispatcherServlet
        DispatcherServlet servlet = new DispatcherServlet(ac);
        ServletRegistration.Dynamic registration = servletContext.addServlet("app", servlet);
        registration.setLoadOnStartup(1);
        registration.addMapping("/");
    }
}

或者继承 AbstractAnnotationConfigDispatcherServletInitializer

public class WebAppInit extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return null;
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{WebConfig1.class};
    }

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

 

4.编写controller

@Controller
public class HelloController {
    @RequestMapping("/hello")
    public String hello(){
        return "hello";
    }
}

5.运行程序，输入http://localhost:8080/hello

注意：在做的过程中，踩得坑，自己装的jdk版本必须跟一下配置匹配，如果不匹配应该修改。

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>