Spring-Webflux与Thymeleaf整合（Could not resolve view with name 'xxxx'）

在Spring-Webflux整合Thymeleaf时，出现Could not resolve view with name ‘xxxx' 问题。个人方法有问题可以打脸，不想看过程直接拉到最后，文中涉及webflux依赖版本为2.1.2

demo项目参考地址: 这是码云

在项目整合Thymeleaf时，无法识别view name问题，debug查找原因。

在 ServerResponseResultHandler做结果处理时会使用ViewResolverRegistry中注册的视图解析器，但是这个地方debug发现视图解析器是0个。

WebFluxConfigurationSupport涉及源码：

	@Bean
	public ServerResponseResultHandler serverResponseResultHandler() {
		List resolvers = getViewResolverRegistry().getViewResolvers();
		ServerResponseResultHandler handler = new ServerResponseResultHandler();
		handler.setMessageWriters(serverCodecConfigurer().getWriters());
		handler.setViewResolvers(resolvers);
		return handler;
	}

WebFluxConfigurationSupport -> ViewResolverRegistry.viewResolvers 是空的，下面就找这个resolverRegistry注册viewResovlers的地方。

WebFluxConfigurationSupport部分源码，此处是获取了视图解析器：

       //此处注入视图结果处理器，其中会获取视图解析器并设置
	@Bean
	public ViewResolutionResultHandler viewResolutionResultHandler() {
		ViewResolverRegistry registry = getViewResolverRegistry();
		List resolvers = registry.getViewResolvers();
		ViewResolutionResultHandler handler = new ViewResolutionResultHandler(
				resolvers, webFluxContentTypeResolver(), webFluxAdapterRegistry());
		handler.setDefaultViews(registry.getDefaultViews());
		handler.setOrder(registry.getOrder());
		return handler;
	}

getViewResolverRegistry方法：里面有个调用配置视图解析器的方法configureViewResolvers

	protected final ViewResolverRegistry getViewResolverRegistry() {
		if (this.viewResolverRegistry == null) {
			this.viewResolverRegistry = new ViewResolverRegistry(this.applicationContext);
			configureViewResolvers(this.viewResolverRegistry);
		}
		return this.viewResolverRegistry;
	}

configureViewResolvers方法：

	/**
	 * Configure view resolution for supporting template engines.
	 * @see ViewResolverRegistry
	 */
	protected void configureViewResolvers(ViewResolverRegistry registry) {
            //留给子类实现的
	}

子类DelegatingWebFluxConfiguration实现了这个方法：

	@Override
	protected void configureViewResolvers(ViewResolverRegistry registry) {
		this.configurers.configureViewResolvers(registry);
	}

这个子类就是@EnableWebFlux中引入的一个配置类，他的源码：

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Import(DelegatingWebFluxConfiguration.class)
public @interface EnableWebFlux {
}

DelegatingWebFluxConfiguration类继承自WebFluxConfigurationSupport并配置了一些webflux的很多处理器

DelegatingWebFluxConfiguration类中注入了所有实现WebFluxConfigurer的bean:

	@Autowired(required = false)
	public void setConfigurers(List configurers) {
		if (!CollectionUtils.isEmpty(configurers)) {
			this.configurers.addWebFluxConfigurers(configurers);
		}
	}

在DelegatingWebFluxConfiguration中有个全局变量WebFluxConfigurerComposite configurers，是聚合WebFlux配置类的一个代理类，这个代理类最终代理了所有实现了WebFluxConfigurer接口的类，并对常用组件做配置。

注入的bean最终被加到了WebFluxConfigurerComposite 中。所以只需要实现一个WebFluxConfigurer就可以对WebFluxConfigurer就可以对视图解析器进行配置，类似Spring-web中的WebMvcConfigurer。

下面具体配置类：解决找不到视图的问题

package tom.reactor.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.reactive.config.ResourceHandlerRegistry;
import org.springframework.web.reactive.config.ViewResolverRegistry;
import org.springframework.web.reactive.config.WebFluxConfigurer;
import org.thymeleaf.spring5.view.reactive.ThymeleafReactiveViewResolver;

/**
 * 提供了自定义配置WebFlux相关组件
 * @author aisheishei
 */
@Configuration
public class WebFluxConfig implements WebFluxConfigurer {

    //引入spring-boot-starter-thymeleaf自动会注入该bean
    @Autowired
    private ThymeleafReactiveViewResolver thymeleafReactiveViewResolver;

    /**
     * 加入thymeleaf试图解析器，不然找不到view name
     * @param registry
     */
    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        registry.viewResolver(thymeleafReactiveViewResolver);
    }

    /**
     * 映射静态资源文件映射
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**")
                //指向的是目录
                .addResourceLocations("classpath:/static/");
    }
}

此时就可以找到controller中返回的视图了