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| package com.fkereki.rssread.client;
//... "import" lines ...
public class Rssreader implements EntryPoint {
// ... variable definitions...
public void onModuleLoad() {
// set up the form and its fields
// call getFeedViaProxy(...) or getFeedViaGoogle(...)
// depending on the listbox value
}
void getFeedViaProxy(final String feedUrl) {
// connect to the remote server via RPC
// when data arrives, call processAndShowFeed(...)
}
native void getFeedViaGoogle(final String feedUrl) /*-{
// call Google Feed API (using native JavaScript, not Java)
// when data arrives, call processAndShowFeed(...)
}-*/;
void processAndShowFeed(final String xmlDocument) {
// clear results from a previous run, if any
// decide whether it's RSS or Atom, and call
// processRssFeed() or processAtomFeed() as required
}
void processRssFeed(final Element root) {
// navigate a RSS feed, extraction titles, descriptions,
// and links, and using showFeedItem(...) to show them
}
void processAtomFeed(final Element root) {
// navigate an Atom feed, extraction titles, descriptions,
// and links (by using getValueIfPresent(...) and
// getLinkIfPresent(...), and showFeedItem(...) to show them
}
private String getValueIfPresent(final Element el, final String tn) {
// get an XML node, and return the value that corresponds to a certain tag
}
private String getLinkIfPresent(final Element el) {
// given a XML "link" node, return the corresponding address
}
private void showFeedItem(final String title, final String description,
final String link) {
// add some lines to the screen, with the data for the latest news
}
}
|
当提要回来时，我不做任何特殊的处理，而只是简单地显示主要的新闻标题、一个简短的描述和一个链接。您可以按您所想，获得尽量多的提要，在新数据显示之前，先前的数据会被删除。 给出了一个实际运行的例子。
总之，这个程序的总体结构如 所示。出于简明的原因，我对每个方法都进行了简短的说明，并借此缩短了需要显示的代码。我稍后会详细介绍每个方法内的代码。参见 获得完整的原始代码。