springmvc注解开发

Z时代
2024-01-10
分类：综合

ps : 这东西比较简单,用来为我们使用springboot打基础

一 : 工程搭建

(一) 导包

<!-- 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>

(二) 日志配置

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>
    <!-- 将springweb下面的包设置成debug,报错信息会比较全面 -->
    <logger name="org.springframework.web" level="debug"/>
    <root level="info">
        <appender-ref ref="console" />
    </root>
</configuration>

(三) web配置

WebApplicationInitializer 是Spring 提供用来配置Servlet 3.0+配置的接口，从而实现了替代web.xml的位置。实现此接口将会自动被SpringServletContainerInitializer (用来启动Servlet3.0容器)获取到。

新建WebApplicationContext,注册配置类，并将其和当前servletContext关联。

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);
    }
}

(四) springmvc配置

@EnableWebMvc会开启一些默认配置,比如ViewResolver和MessageConverter

注意 : 这里的视图解析器(springmvc的核心渲染机制)无论使用哪个实现类,其方法名(也就是id)要写其接口的名字

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig {
    /*
    视图解析器
     */
    @Bean
    public InternalResourceViewResolver viewResolver(){
        return new InternalResourceViewResolver(){{
           setPrefix("/");
           setSuffix(".jsp");
           setViewClass(JstlView.class);
        }};
    }
}

(五) 页面

index.jsp

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

二 : 基本配置

springmvc中的一些定制配置需要我们继承一个类(WebMvcConfigurerAdapter)

并且在配置类上标注@EnableWebMvc

(一) 静态资源映射

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig implements WebMvcConfigurer {
    /*
    静态资源映射
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/img/**").addResourceLocations("classpath:/img/");
    }
}

(二) 拦截器

自定义拦截器

public class HelloInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, 
                             HttpServletResponse response, 
                             Object handler) throws Exception {
        System.out.println("前置...");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, 
                           HttpServletResponse response, 
                           Object handler, 
                           ModelAndView modelAndView) throws Exception {
        System.out.println("后置...");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, 
                                HttpServletResponse response, 
                                Object handler, 
                                Exception ex) throws Exception {
        System.out.println("完成...");
    }
}

配置拦截器

@Configuration
@EnableWebMvc
@ComponentScan("club.info.springmvc")
public class SpringMvcConfig implements WebMvcConfigurer {
    /*
    拦截器
     */
    @Bean
    public HelloInterceptor helloInterceptor(){
        return new HelloInterceptor();
    }
    /*
    配置拦截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(helloInterceptor()).addPathPatterns("/hello");
    }
}