Question

在GWT中执行RequestBuilder的正确方法是什么才能完全按照纯HTML进行操作：

<form action="javascript:;" method="post" data-field="form">
      <input class="rounded" name="username" size="20" type="text" data-field="username">
      <input class="rounded" name="password" size="20" type="password" data-field="password">
      <button class="submit" type="submit" value="Login" data-field="button"><br>
</form>

Answer 1

虽然你可以使用gwt小部件包装每个输入，但对于大型表单，最好迭代所有表单元素，读取它们的名称和值，并生成一个查询字符串以作为数据发送到requestBuilder，这代码应该工作：

  String payload = "";
  Element e = DOM.getElementById("form");
  // you need make this recursive if you want grand-children
  for (int i = 0, l = e.getChildCount(); i < l; i++) {
    Element c = e.getChild(i).cast();
    if (c.getTagName().toLowerCase().matches("input")) {
      String name = c.<InputElement>cast().getName();
      String value = c.<InputElement>cast().getValue();
      payload += name + "=" + value + "&";
    }
  }

  RequestBuilder b = new RequestBuilder(POST, "/my_servlet");
  try {
    b.sendRequest(payload, new RequestCallback() {
      public void onResponseReceived(Request request, Response response) {
         String resp = response.getText();
      }
      public void onError(Request request, Throwable exception) {
      }
    });
  } catch (RequestException ex) {
    ex.printStackTrace();
  }

但是，我更喜欢使用gwtquery口号：（do more, write less）：

  Properties data = Properties.create();
  // This loop also gets grand-children, and you can use more sophisticated css selectors
  for (Element e: $("form").find("input").elements()) {
    data.set($(e).attr("name"), $(e).val());
  }

  GQuery.post("/my_servlet", data, new Function(){
    public void f(){
      // Use getDataObjet in non snapshot versions
      String response = arguments(0);
    };
  });

Answer 2

首先构建一个类似下面的请求（伪代码）：

RequestBuilder req= new RequestBuilder(RequestBuilder.POST, url);
req.setHeader("Content-Type","application/x-www-form-urlencoded");


StringBuilder sb = new StringBuilder();
sb.append(URL.encodeComponent("usename="+usernameVal+"&"));
sb.append(URL.encodeComponent("password="+passwordval));//add & if more params.


req.setRequestData(sb.toString());
req.setCallback(new RequestCallback() {

        @Override
        public void onResponseReceived(Request request, Response response) {
           //TO DO
        }

        @Override
        public void onError(Request request, Throwable exception) {
        }
    });

在提交按钮中单击处理程序：

try {
       req.send();
    }
catch (Exception e){
       e.printStackTrace();

    }
}

它们有点陈旧但仅供参考：RequestBuilderUsage和GeetingResponse through GWT HTTP。

我希望以上几行能给出一些基本的想法

使用RequestBuilder表单发布

2 个答案: