java到js的中文无法显示，中文显示位(?)

今天遇到这么一个问题，用js调用java的get请求，得到的json数据中中文无法正常显示，jsp文件中都是申明utf-8格式的，查询了一番，发现问题出现在@ResponseBody上

@ResponseBody默认的编码格式为ISO-8859-1，需要修改，在@GetMapping中加入produces的内容

参考：springmvc @ResponseBody乱码，兼容UTF-8格式

java代码

@Controller
public class ExamController {
	@Autowired
	private ExamService examService;

	@GetMapping(value = "/getPaper", produces = "application/json; charset=utf-8")
	@ResponseBody
	public String getPaper(HttpSession session) {
		Paper paper = null;
		try {
			paper = this.examService.getPaper();
		}catch(SystemException e){
			session.setAttribute("msg", e.getMessage());
		}catch(Exception e1) {
			e1.printStackTrace();
		}
		System.out.println(paper.toString());
		return paper.toString();
	}
}

或者配置文件中添加bean

<bean class = "org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
	<property name="messageConverters">
		  <array>
		        <bean class = "org.springframework.http.converter.StringHttpMessageConverter">
		            <property name="supportedMediaTypes" value = "text/plain;charset=UTF-8" />
		        </bean>
		</array>
	</property>
</bean>