SpringBoot(八):springboot的Web开发

Web开发的自动配置类:org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration

1.自动配置的ViewResolver(视图解析器)

    在没有自定义配置ViewResolver情况下,springboot会自动启用默认配置

            

    视图的配置mvcProperties对象中:

    org.springframework.boot.autoconfigure.web.WebMvcProperties.View

    

    当然视图解析器的前缀后缀可以在全局配置文件中自己定义:

    

2.自动配置静态资源

    2.1进入规则

        如果进入SpringMVC的规则为/(也是springboot的默认进入规则),并且设置了Spring Boot的默认静态资源的路径为:

        spring.resources.static-locations=

  classpath:/META-INF/resources/,classpath:/resources/,classpath:/static/,classpath:/public/       

        那么将只能访问指定路径下的文件

        PS:classpath为项目根路径,如classpath:/public/对应的位置为:

        

        2.2进入规则为*.xxx 或者 默认规则但不指定静态文件路径时      

            将静态资源放置到webapp下即可通过地址访问

3.自定义消息转化器

    自定义消息转化器,只需要在@Configuration的类中添加消息转化器的@bean加入到Spring容器,就会被Spring Boot自动加入到容器中

    @Bean
    public StringHttpMessageConverter stringHttpMessageConverter(){
        StringHttpMessageConverter converter  = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        return converter;
    }

    默认配置:



4.自定义SpringMVC的配置

    有些时候我们需要自已配置SpringMVC而不是采用默认,比如说增加一个拦截器,这个时候就得通过继承WebMvcConfigurerAdapter然后重写父类中的方法进行扩展。

import java.nio.charset.Charset;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration //申明这是一个配置
public class MySrpingMVCConfig extends WebMvcConfigurerAdapter{

    // 自定义拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        HandlerInterceptor handlerInterceptor = new HandlerInterceptor() {
            @Override
            public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
                    throws Exception {
                System.out.println("自定义拦截器............");
                return true;
            }
            
            @Override
            public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
                    ModelAndView modelAndView) throws Exception {
                
            }
            
            @Override
            public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
                    Exception ex) throws Exception {
            }
        };
        registry.addInterceptor(handlerInterceptor).addPathPatterns("/**");
    }

    // 自定义消息转化器的第二种方法
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        StringHttpMessageConverter converter  = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        converters.add(converter);
    }

}

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转载自blog.csdn.net/qq_37725650/article/details/80187032