服务器向浏览器输出信息

1.获取HttpServletResponse输出流

2.写入内容到HttpServletResponse 的输出流

　　HttpServletResponse对象代表服务器的响应。这个对象中封装了向客户端发送数据、发送响应头，发送响应状态码的方法。

/**
*  服务器像浏览器输出信息
*response 在  BaseController 里
*/
@Controller
public class PreviewController extends BaseController {

    @Autowired
    PageService pageService;

    //页面预览
    @RequestMapping(value="/preview/{pageId}",method = RequestMethod.GET)
    public void preview(@PathVariable("pageId") String pageId) throws IOException {
        //执行静态化
        String pageHtml = pageService.getPageHtml(pageId);
        //通过response对象将内容输出
        ServletOutputStream outputStream = response.getOutputStream();

        outputStream.write(pageHtml.getBytes("utf-8"));

    }
}

上面这个我做的是一个静态页面的预览，

pageHtml.getBytes("utf-8") 这个我输出的是一个html的内容

import org.springframework.web.bind.annotation.ModelAttribute;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Created on 2020/3/15.
 */
public class BaseController {
    protected HttpServletRequest request;

    protected HttpServletResponse response;

    protected HttpSession session;

    @ModelAttribute
    public void setReqAndRes(HttpServletRequest request, HttpServletResponse response) {

        this.request = request;

        this.response = response;

        this.session = request.getSession();

    }
}