Springboot使用ResponseBody汉字返回问号问题

   <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>text/plain;charset=UTF-8</value>
                        <value>text/html;charset=UTF-8</value>
                    </list>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        StringHttpMessageConverter converter = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        converters.add(converter);
    }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
 
import java.nio.charset.StandardCharsets;
import java.util.List;
 
@Configuration
public class WebConfig extends WebMvcConfigurationSupport {
    
    @Override
    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        // 解决controller返回字符串中文乱码问题
        for (HttpMessageConverter<?> converter : converters) {
            if (converter instanceof StringHttpMessageConverter) {
                ((StringHttpMessageConverter)converter).setDefaultCharset(StandardCharsets.UTF_8);
            }
        }
    }
 
}