wx-tools 完善菜單欄的功能

2.6.1 按鈕[分類(lèi)-飆升榜]

需求：當(dāng)用戶(hù)點(diǎn)擊此按鈕，后臺(tái)爬蟲(chóng)幫我爬當(dāng)天酷狗飆升榜的列表下來(lái)，并返回。 酷狗飆升榜在這。

• 爬蟲(chóng)技術(shù)不是本文檔的主要內(nèi)容，所以在此就不細(xì)講如何爬下數(shù)據(jù)。有興趣的同學(xué)可以閱讀下源代碼。（原理很簡(jiǎn)單，僅僅使用HttpClient+Jsoup）

添加RankHandler.java

此handler專(zhuān)門(mén)處理爬蟲(chóng)分類(lèi)Event事件。

RankHandler.java:(負(fù)責(zé)處理消息部分)

public class RankHandler implements WxMessageHandler {
    private static RankHandler instance = null;
    private boolean isRun = false;
    private RankHandler() {}
    
    public static synchronized RankHandler getInstance() {
        if (instance == null) {
            instance = new RankHandler();
        }
        return instance;
    }
    @Override
    public WxXmlOutMessage handle(WxXmlMessage wxMessage, Map<String, Object> context, IService iService)
            throws WxErrorException {
        StringBuilder result = new StringBuilder();
        if (!getIsRun()) {
            setRun(true);
            try {
                result = execute(wxMessage);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                setRun(false);
            }
        } else {
            result.append(ResponseConst.DUPLICATE_REQUEST);
        }
        return WxXmlOutMessage.TEXT().content(result.toString()).toUser(wxMessage.getFromUserName()).fromUser(wxMessage.getToUserName()).build();
    }
    private StringBuilder execute(WxXmlMessage wxMessage) throws Exception{
        StringBuilder stringBuilder = new StringBuilder();
        try {
            switch (wxMessage.getEventKey()) {
                case MenuKey.HOT_SONG:
                    collectSongRank(stringBuilder, UrlConst.HOT_RANK_URL);
                    break;
                default:
                    stringBuilder.append("暫時(shí)無(wú)此分類(lèi)噢！");
                    break;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return stringBuilder;
    }
    private void collectSongRank(StringBuilder stringBuilder, String url) throws IOException {
        RankCollector collector = new RankCollector();
        Rank rank = collector.collect(url);
        stringBuilder.append("\uD83D\uDD25" + rank.getScope() + "[" + rank.getUpdateTime() + "]\n\n");
        for (HotSinger hotSinger : rank.getHotSingerList()) {
            stringBuilder.append(hotSinger.getName() + "-" + hotSinger.getHotSong() + "\n");
        }
    }
    private synchronized boolean getIsRun() {
        return isRun;
    }
    private synchronized void setRun(boolean run) {
        isRun = run;
    }
}

RankCollector.java: (爬蟲(chóng)部分)

public class RankCollector {
    public Rank collect(String url) throws IOException {
        return getRank(url);
    }
    private Rank getRank(String rankUrl) throws IOException {
        Rank rank = new Rank();
        String body = HttpClientUtil.get(rankUrl);
        Document doc = Jsoup.parse(body);
        rank.setScope(doc.select("a[class=current]").attr("title"));
        rank.setUpdateTime(doc.select("span[class=rank_update]").text());
        List<Element> aElements = doc.select("a[data-active=playDwn]");
        for(int i = 0; i < aElements.size(); i++){
            String[] splitArray = aElements.get(i).text().split("-");
            String name = splitArray[0].toString().trim();
            String song = splitArray[1].toString().trim();
            rank.getHotSingerList().add(new HotSinger(doc.select("a[class=current]").attr("title"), name, song));
        }
        return rank;
    }
}

添加新的規(guī)則（Rule）

修改新增WxController的路由規(guī)則：

router.rule().event(WxConsts.EVT_CLICK).eventKey(MenuKey.HELP).handler(HelpDocHandler.getInstance()).next()
                    .rule().eventKey(MenuKey.HOT_SONG).handler(RankHandler.getInstance()).end();

• 這里解釋一下：next()和end()的意思。
• next() 表示消息經(jīng)過(guò)第一個(gè)規(guī)則（Rule）之后，允許繼續(xù)匹配下面的規(guī)則，代表著同一個(gè)消息有可能被多個(gè)Handler處理。
• end() 表示規(guī)則的結(jié)束。當(dāng)消息滿(mǎn)足某條規(guī)則時(shí)遇到end()，不會(huì)再往下匹配規(guī)則，就此結(jié)束。

重新運(yùn)行，并測(cè)試

當(dāng)天的飆升榜就這樣返回回來(lái)了~很激動(dòng)有木有！

• 好了同一原理實(shí)現(xiàn)其他4個(gè)排行榜按鈕的功能，這里就不展示了。詳情可以查看demo源碼。