Spring Boot 自定义Spring MVC 配置： WebMvcConfigurationSupport

package com.easy.springboot.demo_spring_mvc.mvc_config

import com.alibaba.fastjson.serializer.SerializerFeature
import com.alibaba.fastjson.support.config.FastJsonConfig
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter
import com.easy.springboot.demo_spring_mvc.handler.LoginSessionHandlerInterceptor
import freemarker.template.Configuration
import freemarker.template.TemplateException
import org.slf4j.LoggerFactory
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.context.annotation.Bean
import org.springframework.core.env.Environment
import org.springframework.format.FormatterRegistry
import org.springframework.format.datetime.DateFormatter
import org.springframework.http.converter.HttpMessageConverter
import org.springframework.web.servlet.config.annotation.*
import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer
import org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver
import java.io.IOException


@org.springframework.context.annotation.Configuration
class WebMvcConfig : WebMvcConfigurationSupport() {
    val log = LoggerFactory.getLogger(WebMvcConfig::class.java)
    @Autowired lateinit var loginSessionHandlerInterceptor: LoginSessionHandlerInterceptor
    @Autowired lateinit var environment: Environment

    /**
     * 拦截器配置
     */
    override fun addInterceptors(registry: InterceptorRegistry) {
        super.addInterceptors(registry)
        //注册自定义拦截器，添加拦截路径和排除拦截路径
        registry.addInterceptor(loginSessionHandlerInterceptor).
                addPathPatterns("/**").
                excludePathPatterns(
                        "/index",
                        "/login",
                        "/doLogin",
                        "/logout",
                        "/register",
                        "/doRegister",
                        "/**/*.js",
                        "/**/*.css",
                        "/**/*.css.map",
                        "/**/*.jpeg",
                        "/**/*.ico",
                        "/**/*.jpg",
                        "/**/*.png",
                        "/**/*.woff",
                        "/**/*.woff2"
                )

    }

    /**
     * 静态资源路径映射
     */
    override fun addResourceHandlers(registry: ResourceHandlerRegistry) {
        super.addResourceHandlers(registry)
        registry.addResourceHandler("/app/**").addResourceLocations("classpath:/static/app/")
        registry.addResourceHandler("/bower_components/**").addResourceLocations("classpath:/static/bower_components/")

    }


//    @GetMapping(value = ["/index"])
//    fun index(): String {
//        return "index"
//    }
//
//    @GetMapping(value = ["/about"])
//    fun about(): String {
//        return "about"
//    }
//
//    @GetMapping(value = ["/error/403"])
//    fun error_403(): String {
//        return "error/403"
//    }
//
//    @GetMapping(value = ["/error/500"])
//    fun error_500(): String {
//        return "error/500"
//    }
    /**
     * View - Controller 映射配置
     */
    override fun addViewControllers(registry: ViewControllerRegistry) {
        super.addViewControllers(registry)

        registry.addViewController("/").setViewName("/index")
        registry.addViewController("/index").setViewName("/index")
        registry.addViewController("/about").setViewName("/about")
        registry.addViewController("/error/403").setViewName("/error/403")
        registry.addViewController("/error/500").setViewName("/error/500")
    }

    /**
     * 重写 addCorsMappings方法:
    addMapping：配置可以被跨域的路径，可以任意配置，可以具体到直接请求路径。
    allowedMethods：允许所有的请求方法访问该跨域资源服务器，如：POST、GET、PUT、DELETE等。
    allowedOrigins：允许所有的请求域名访问我们的跨域资源，可以固定单条或者多条内容，如："http://www.baidu.com"，只有百度可以访问我们的跨域资源。
    allowedHeaders：允许所有的请求header访问，可以自定义设置任意请求头信息，如："X-TOKEN"
     */
    override fun addCorsMappings(registry: CorsRegistry) {
        super.addCorsMappings(registry)
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("*")
                .allowedHeaders("*")


    }


    /**
     *
     * FreeMarker视图配置
     * 配置了@Bean注解，该注解会将方法返回值加入到Spring Ioc 容器内。
     * @return
     */
    @Bean
    fun freeMarkerViewResolver(): FreeMarkerViewResolver {
        val viewResolver = FreeMarkerViewResolver()
        // freemarker本身配置了templateLoaderPath而在viewResolver中不需要配置prefix，且路径前缀必须配置在 templateLoaderPath 中
        viewResolver.setPrefix("")
        viewResolver.setSuffix(".ftl")
        viewResolver.isCache = false
        viewResolver.setContentType("text/html;charset=UTF-8")
        viewResolver.setRequestContextAttribute("requestContext") //为模板调用时，调用 request 对象的变量名
        viewResolver.order = 0
        viewResolver.setExposeRequestAttributes(true);
        viewResolver.setExposeSessionAttributes(true);
        return viewResolver
    }


    /**
    spring.freemarker.suffix=.ftl
    spring.freemarker.templateEncoding=UTF-8
    spring.freemarker.templateLoaderPath=classpath:/templates/

     * 1.spring和freemarker的整合，需要定义两个bean：FreeMarkerViewResolver、FreeMarkerConfigurer。
     * 2.spring在Dispatcher中定义了视图渲染的过程:创建视图，然后利用Freemarker本身提供的Template方法来处理。
     */
    @Bean
    fun freemarkerConfig(): FreeMarkerConfigurer {
        val freemarkerConfig = FreeMarkerConfigurer()
        freemarkerConfig.setDefaultEncoding("UTF-8")
        freemarkerConfig.setTemplateLoaderPath("classpath:/templates/")
        var configuration: Configuration? = null
        try {
            configuration = freemarkerConfig.createConfiguration()
            configuration.defaultEncoding = "UTF-8"
        } catch (e: IOException) {
            log.error("freemarker配置bean，IO异常: {}", e)
        } catch (e: TemplateException) {
            log.error("freemarker配置bean，TemplateException 异常: {}", e)
        }

        val freemarkerVars = mutableMapOf<String, Any>()
        freemarkerVars["rootContextPath"] = environment.getProperty("root.context.path")
        freemarkerConfig.setFreemarkerVariables(freemarkerVars)
        return freemarkerConfig
    }

    /**
     * 配置视图解析器：ViewResolver
     * ########################################################
    ###FREEMARKER (FreeMarkerAutoConfiguration)
    ########################################################
    spring.freemarker.allow-request-override=false
    spring.freemarker.cache=true
    spring.freemarker.check-template-location=true
    spring.freemarker.charset=UTF-8
    spring.freemarker.content-type=text/html
    spring.freemarker.expose-request-attributes=false
    spring.freemarker.expose-session-attributes=false
    spring.freemarker.expose-spring-macro-helpers=false
    #spring.freemarker.prefix=
    #spring.freemarker.request-context-attribute=
    #spring.freemarker.settings.*=
    spring.freemarker.suffix=.ftl
    spring.freemarker.template-loader-path=classpath:/templates/
    #comma-separated list
    #spring.freemarker.view-names= # whitelist of view names that can be resolved
     */
    override fun configureViewResolvers(registry: ViewResolverRegistry) {
        super.configureViewResolvers(registry)
        registry.viewResolver(freeMarkerViewResolver())
    }

    /**
     * 配置消息转换器
     */
    override fun configureMessageConverters(converters: MutableList<HttpMessageConverter<*>>) {
        super.configureMessageConverters(converters)
        //创建fastjson消息转换器: FastJsonHttpMessageConverter
        val fastConverter = FastJsonHttpMessageConverter()
        //创建 FastJsonConfig 配置类
        val fastJsonConfig = FastJsonConfig()
        //定制过滤 JSON 返回
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.WriteNullNumberAsZero,
                SerializerFeature.DisableCircularReferenceDetect,
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.WriteNullStringAsEmpty
        )
        fastConverter.setFastJsonConfig(fastJsonConfig)
        //将 fastConverter 添加到视图消息转换器列表内
        converters.add(fastConverter)

    }

    override fun addFormatters(registry: FormatterRegistry) {
        super.addFormatters(registry)
        registry.addFormatter(DateFormatter("yyyy-MM-dd"))
    }


}