Spring Web MVC

控制器响应消息体

@ResponseBody
这是指定响应的消息体

字符串

<bean class="org.springframework.http.converter.StringHttpMessageConverter" />

图片

<bean class="org.springframework.http.converter.BufferedImageHttpMessageConverter" />

json

<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />

例子

例子1：返回验证码

    @ResponseBody
    @GetMapping(value = "/code", produces = MediaType.IMAGE_PNG_VALUE)
    public Image generateVC(HttpServletRequest req, HttpServletResponse resp) {
        String code = CommonUtil.verifyCodeStr(4);
        BufferedImage image = CommonUtil.codeStrImage(code, 72, 20);
        req.getSession().setAttribute("code", code);
        return image;
    }