Java用JSoup组件提取asp.net webform开发网页的viewstate相关相关参数

/**
* 从页面中提取特定input的的Value
* @param formparams
* @param document
* @param elementId
*/
private void addFormHiddenElementValue(List<BasicNameValuePair> formparams,
Document document, String elementId) {
Element element = document.getElementById(elementId);
if(element != null){
String elementValue = element.attr("value");
formparams.add(new BasicNameValuePair(elementId,elementValue));
}
}

/**
* 取得对应URL的Document实例
* @param url
* @return
*/
private static Document getDocument(String url) {
Document document = null;
try {
document = Jsoup.connect(url).get();
} catch (IOException e) {
e.printStackTrace();
}
return document;
}

Document document = getDocument(url);
if(document != null){
List<String> elementIds = new ArrayList<String>();
elementIds.add("__VIEWSTATE");
elementIds.add("__VIEWSTATEGENERATOR");
elementIds.add("__EVENTVALIDATION");
for(String elementId : elementIds){
addFormHiddenElementValue(formparams, document, elementId);
}
}