springboot实现返回视图而不是string的方法

package com.example.demo.controller;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@EnableAutoConfiguration
public class HelloController {
    @RequestMapping("/hello")
    public String hello() {
        System.out.println("进入controller");
        return "hello";
    }
}

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
@Controller
@EnableAutoConfiguration
public class HelloController {
    @RequestMapping("/hello")
    @ResponseBody
    public ModelAndView hello(){
        System.out.println("hello!");
        ModelAndView mode = new ModelAndView();
        mode.setViewName("hello");
        return mode;
    }
}

    @RequestMapping("toTest")
    public ModelAndView toTest(){
        ModelAndView mv = new ModelAndView();
        //视图名
        mv.setViewName("login");
        //想传的数据
        mv.addObject("o1","数据1");
        return mv;
    }

package com.ch.exercise.config.webMvc;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
/**
 * MVC配置
 * @author CH
 * @date 2021-08-19 11:45
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry
        //接收的请求
        .addViewController("/toLogin")
        //跳转的页面名
        .setViewName("login");
    }
}

		<!--web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--thymeleaf-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

spring:
  thymeleaf:
  	#页面存放位置
    prefix: classpath:/templates/
    #是否缓存 这里是否
    cache: false
    suffix: .html
    mode: LEGACYHTML5
    template-resolver-order: 0