Spring MVC annotation development

ps: it's relatively simple. It's used to lay the foundation for us to use springboot

I. project construction

(1) guide packet

<!-- servlet -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.0</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>jsp-api</artifactId>
    <version>2.2</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>jstl</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>

<!-- spring -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.1.7.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>5.1.7.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.1.7.RELEASE</version>
</dependency>

<!-- logback -->
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-core</artifactId>
    <version>1.2.3</version>
</dependency>
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.2.3</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-access</artifactId>
    <version>1.2.3</version>
</dependency>

(II) log configuration

logback.xml

<?xml version="1.0" encoding="utf-8" ?>
<configuration>

    <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator">
        <resetJUL>true</resetJUL>
    </contextListener>

    <jmxConfigurator/>

    <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>logback: %d{HH:mm:ss.SSS} %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <!-- take springweb The following package is set to debug,Error reporting information will be more comprehensive -->
    <logger name="org.springframework.web" level="debug"/>

    <root level="info">
        <appender-ref ref="console" />
    </root>
</configuration>

(3) web configuration

WebApplicationInitializer is an interface provided by Spring to configure Servlet 3.0 + configuration, thus realizing the position of replacing web.xml. Implementing this interface will be automatically retrieved by the SpringServletContainerInitializer (used to start the Servlet3.0 container).
Create a new WebApplicationContext, register the configuration class, and associate it with the current servletContext.

public class WebInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        AnnotationConfigWebApplicationContext context = 
            new AnnotationConfigWebApplicationContext();
        context.register(SpringMvcConfig.class);
        context.setServletContext(servletContext);

        ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", new DispatcherServlet(context));
        dispatcher.addMapping("/");
        dispatcher.setLoadOnStartup(1);

    }
}

(IV) spring MVC configuration

@EnableWebMvc will enable some default configurations, such as ViewResolver and MessageConverter

Note: no matter which implementation class the view parser (the core rendering mechanism of spring MVC) uses, its method name (i.e. id) should write the name of its interface

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig {

    /*
    view resolver 
     */
    @Bean
    public InternalResourceViewResolver viewResolver(){
        return new InternalResourceViewResolver(){{
           setPrefix("/");
           setSuffix(".jsp");
           setViewClass(JstlView.class);
        }};
    }
}

(five) page

index.jsp

<html>
    <body>
        <h2>Hello World!</h2>
    </body>
</html>

II. Basic configuration

Some custom configurations in spring MVC require us to inherit a class (WebMvcConfigurerAdapter)
And mark @ EnableWebMvc on the configuration class

(I) static resource mapping

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig implements WebMvcConfigurer {
    
    /*
    Static resource mapping
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/img/**").addResourceLocations("classpath:/img/");
    }
}

(II) interceptor

custom interceptor

public class HelloInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, 
                             HttpServletResponse response, 
                             Object handler) throws Exception {

        System.out.println("Preposition...");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, 
                           HttpServletResponse response, 
                           Object handler, 
                           ModelAndView modelAndView) throws Exception {
        System.out.println("Postposition...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, 
                                HttpServletResponse response, 
                                Object handler, 
                                Exception ex) throws Exception {
        System.out.println("complete...");
    }
}

Configuring Interceptors

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig implements WebMvcConfigurer {

    /*
    Interceptor
     */
    @Bean
    public HelloInterceptor helloInterceptor(){
        return new HelloInterceptor();
    }

    /*
    Configuring Interceptors 
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(helloInterceptor()).addPathPatterns("/hello");
    }
}

(to be continued)

Keywords: Programming Spring JSP xml SpringBoot

Added by zyntax on Wed, 20 Nov 2019 16:41:11 +0200

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