Spring Boot 切换至 JSP 视图模板引擎 及与 Thymeleaf 共存

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@SpringBootApplication
public class Hi {

    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
    }
}

@Controller
class HelloWorld {

    @RequestMapping("/")
    public String welcome() {
        return "index"; // 多引擎共存要写明文件后缀：index.jsp index.html等
    }
}


@Configuration // Thymeleaf 与 JSP 共存配置; 无需在application.yml中配置spring mvc view了
public class OurSpringWebMvcConfigurer implements WebMvcConfigurer {

    @Autowired
    WebApplicationContext webApplicationContext;

    @Bean
    public SpringResourceTemplateResolver thymeleafTemplateResolver() {
        var templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setApplicationContext(webApplicationContext);
        templateResolver.setOrder(9);
        templateResolver.setPrefix("classpath:/templates/");
        return templateResolver;
    }

    @Bean
    public SpringTemplateEngine templateEngine() {
        var springTemplateEngine = new SpringTemplateEngine();
        springTemplateEngine.setTemplateResolver(thymeleafTemplateResolver());
        springTemplateEngine.setEnableSpringELCompiler(true);
        return springTemplateEngine;
    }

    @Bean
    public ThymeleafViewResolver thymeleafViewResolver() {
        var viewResolver = new ThymeleafViewResolver();
        viewResolver.setViewNames(new String[]{"*.html"});
        viewResolver.setExcludedViewNames(new String[]{"*.jsp"});
        viewResolver.setTemplateEngine(templateEngine());
        viewResolver.setCharacterEncoding("UTF-8");
        return viewResolver;
    }

    @Bean
    public InternalResourceViewResolver jspViewResolver() {
        var viewResolver = new InternalResourceViewResolver();
        viewResolver.setOrder(10);
        viewResolver.setPrefix("/WEB-INF/views/");
        viewResolver.setViewNames("*.jsp");
        //viewResolver.setViewClass(JstlView.class);
        return viewResolver;
    }
}