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社区首页 >问答首页 >如何手动将Spring MVC视图渲染为html?

如何手动将Spring MVC视图渲染为html?
EN

Stack Overflow用户
提问于 2014-03-15 18:14:25
回答 3查看 24.5K关注 0票数 30

是否可以在控制器映射方法中将视图呈现为html,以便我可以将呈现的html作为json对象的一部分返回?

我常用的控制器方法示例:

代码语言:javascript
复制
@RequestMapping(value={"/accounts/{accountId}"}, method=RequestMethod.GET)
public String viewAcc(final HttpServletRequest req, 
        final HttpServletResponse resp, final Model model,
        @PathVariable("accountId") final String docId) {

    // do usual processing ...

    // return only a STRING value, 
    //   which will be used by spring MVC to resolve into myview.jsp or myview.ftl
    //   and populate the model to the template to result in html
    return "myview";
}

我期望的是:

代码语言:javascript
复制
@RequestMapping(value={"/accounts/{accountId}"}, method=RequestMethod.GET)
public String viewAcc(final HttpServletRequest req, 
        final HttpServletResponse resp, final Model model,
        @PathVariable("accountId") final String docId) {

    // do usual processing ...

    // manually create the view
    ModelAndView view = ... ? (how)

    // translate the view to the html
    //   and get the rendered html from the view
    String renderedHtml = view.render .. ? (how)

    // create a json containing the html
    String jsonString = "{ 'html' : " + escapeForJson(renderedHtml) + "}"

    try {
        out = response.getWriter();
        out.write(jsonString);
    } catch (IOException e) {
        // handle the exception somehow
    }

    return null;
}

我想知道在控制器方法中手动创建视图并将视图呈现为html的正确方法是什么。

更新

以下是可接受答案的指导中的工作示例:

代码语言:javascript
复制
View resolvedView = thiz.viewResolver.resolveViewName("myViewName", Locale.US);
MockHttpServletResponse mockResp = new MockHttpServletResponse();
resolvedView.render(model.asMap(), req, mockResp);
System.out.println("rendered html : " + mockResp.getContentAsString());
EN

回答 3

Stack Overflow用户

回答已采纳

发布于 2014-03-15 18:58:09

尝试自动安装ViewResolver,然后调用resolveViewName("myview", Locale.US)来获取视图。

然后在视图上调用render(),向它传递一个“模拟”HTTP响应,该响应的输出是一个ByteArrayOutputStream,并从ByteArrayOutputStream获取HTML.

更新

下面是从问题中复制过来的工作示例。(所以代码实际上就是答案)

代码语言:javascript
复制
View resolvedView = thiz.viewResolver.resolveViewName("myViewName", Locale.US);
MockHttpServletResponse mockResp = new MockHttpServletResponse();
resolvedView.render(model.asMap(), req, mockResp);
System.out.println("rendered html : " + mockResp.getContentAsString());
票数 25
EN

Stack Overflow用户

发布于 2015-12-02 17:40:53

如果您希望在与DispatcherServlet呈现视图相同的区域设置下呈现视图,请尝试复制它的render-method:

代码语言:javascript
复制
/** LocaleResolver used by this servlet */
private LocaleResolver localeResolver;

/** List of ViewResolvers used by this servlet */
private List<ViewResolver> viewResolvers;

/**
 * Render the given ModelAndView.
 * <p>This is the last stage in handling a request. It may involve resolving the view by name.
 * @param mv the ModelAndView to render
 * @param request current HTTP servlet request
 * @param response current HTTP servlet response
 * @throws ServletException if view is missing or cannot be resolved
 * @throws Exception if there's a problem rendering the view
 */
protected void render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response) throws Exception {
    // Determine locale for request and apply it to the response.
    Locale locale = this.localeResolver.resolveLocale(request);
    response.setLocale(locale);

    View view;
    if (mv.isReference()) {
        // We need to resolve the view name.
        view = resolveViewName(mv.getViewName(), mv.getModelInternal(), locale, request);
        if (view == null) {
            throw new ServletException("Could not resolve view with name '" + mv.getViewName() +
                    "' in servlet with name '" + getServletName() + "'");
        }
    }
    else {
        // No need to lookup: the ModelAndView object contains the actual View object.
        view = mv.getView();
        if (view == null) {
            throw new ServletException("ModelAndView [" + mv + "] neither contains a view name nor a " +
                    "View object in servlet with name '" + getServletName() + "'");
        }
    }

    // Delegate to the View object for rendering.
    if (logger.isDebugEnabled()) {
        logger.debug("Rendering view [" + view + "] in DispatcherServlet with name '" + getServletName() + "'");
    }
    try {
        view.render(mv.getModelInternal(), request, response);
    }
    catch (Exception ex) {
        if (logger.isDebugEnabled()) {
            logger.debug("Error rendering view [" + view + "] in DispatcherServlet with name '" +
                    getServletName() + "'", ex);
        }
        throw ex;
    }
}

/**
 * Resolve the given view name into a View object (to be rendered).
 * <p>The default implementations asks all ViewResolvers of this dispatcher.
 * Can be overridden for custom resolution strategies, potentially based on
 * specific model attributes or request parameters.
 * @param viewName the name of the view to resolve
 * @param model the model to be passed to the view
 * @param locale the current locale
 * @param request current HTTP servlet request
 * @return the View object, or {@code null} if none found
 * @throws Exception if the view cannot be resolved
 * (typically in case of problems creating an actual View object)
 * @see ViewResolver#resolveViewName
 */
protected View resolveViewName(String viewName, Map<String, Object> model, Locale locale,
        HttpServletRequest request) throws Exception {

    for (ViewResolver viewResolver : this.viewResolvers) {
        View view = viewResolver.resolveViewName(viewName, locale);
        if (view != null) {
            return view;
        }
    }
    return null;
}

通常情况下,将@Autowired添加到顶部的字段就足够了,但是当自动装配失败时,DispatcherServlet也会采用后备。

票数 1
EN

Stack Overflow用户

发布于 2014-03-15 18:25:42

您可以使用模板库来创建html,例如Velocity。然后,您需要将返回类型定义为

代码语言:javascript
复制
public @ResponseBody SomeObject viewAcc(...) {...}

并且对象本身可以获得html,以及其他一些变量。

票数 -1
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/22422411

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