華為系統更新后安裝了一個谷歌6月安全補丁的東西，然后之前寫的調h5頁面的部分就出現了問題，后台查過發現是Android端調h5頁面時cookie沒能帶過去，導致了登錄失敗。於是對setCookie部分的代碼進行了調試，發現單步運行時只要在setCookie部分時多等一會頁面就可以正常打開，所以懷疑是異步的問題，先是在網上查了一通，說是這種情況可以讓程序多睡會，但是這種解決方法並沒有成功，而且覺得這么寫代碼有點別扭，於是就又查了一下設置Cookie部分的官方說明，發現 cookieManager.removeAllCookies其實是異步函數，之前寫代碼的人把他當同步用了，導致setCookie完成后，removeAllCookies函數才執行完的，把填進去的cookie又給移除了，所以導致了打開頁面的失敗。沒安補丁之前，可能是cookie都帶過去了，remove函數才執行完，安補丁后remov函數的運行速度提升了，但是具體原因不明，因為查不到補丁的內容，總之無論如何，異步函數當同步使用是萬萬不能的。
以下是改之前錯誤的代碼，removeAllCookies被當成了同步函數使用
void fun(){
...
addCookies();
mWebview = (SystemWebView) appView.getView();
engine = (SystemWebViewEngine) appView.getEngine();
mWebview.setWebViewClient(new SystemWebViewClient(engine){
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
}
...
});
}
private void addCookies() {
CookieManager cookieManager = CookieManager.getInstance();
cookieManager.removeAllCookie();
cookieManager.setAcceptCookie(true);
List<Cookie> cookieList = MainApp.getInstance().getGlobalState().getCookies();
for (Cookie cookie: cookieList){
String cookieString = cookie.name() + "=" + cookie.value();
cookieManager.setCookie(url, cookieString);
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
cookieManager.flush();
} else {
CookieSyncManager.createInstance(this);
CookieSyncManager.getInstance().sync();
}
}
以下是改后的代碼，removeAllCookies()有一個完成后會在當前線程調用的方法，利用他remove完成后在set就沒問題了，而且addCookie()的調用被移進了onPageStarted之前，不然，之前那么寫的話會先完成調用onPageStarted()，后完成addCookie()的調用，cookie依然不能設置成功。addCookie()不能放在onPageStarted中，應該加載完cookie再加載url，在loadUrl之前調用。
void fun(){
mWebview = (SystemWebView) appView.getView();
engine = (SystemWebViewEngine) appView.getEngine();
mWebview.setWebViewClient(new SystemWebViewClient(engine){
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
// addCookies();
super.onPageStarted(view, url, favicon);
}
...
});
}
private void addCookies() {
CookieManager cookieManager = CookieManager.getInstance();
cookieManager.setAcceptCookie(true);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
cookieManager.removeAllCookies(new ValueCallback<Boolean>() {
@Override
public void onReceiveValue(Boolean value) {
setCookie(cookieManager);
}
});
}else{
cookieManager.removeAllCookie();
setCookie(cookieManager);
}
}
void setCookie( CookieManager cookieManager){
List<Cookie> cookieList = MainApp.getInstance().getGlobalState().getCookies();
for (Cookie cookie: cookieList){
String cookieString = cookie.name() + "=" + cookie.value();
cookieManager.setCookie(url, cookieString);
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
cookieManager.flush();
} else {
CookieSyncManager.createInstance(this);
CookieSyncManager.getInstance().sync();
}
loadUrl();
}
這是removeAllCookies()方法的完整說明
/**
* Removes all cookies.
* <p>
* This method is asynchronous.
* If a {@link ValueCallback} is provided,
* {@link ValueCallback#onReceiveValue(T) onReceiveValue()} will be called on the current
* thread's {@link android.os.Looper} once the operation is complete.
* The value provided to the callback indicates whether any cookies were removed.
* You can pass {@code null} as the callback if you don't need to know when the operation
* completes or whether any cookies were removed, and in this case it is safe to call the
* method from a thread without a Looper.
* @param callback a callback which is executed when the cookies have been removed
*/
public abstract void removeAllCookies(ValueCallback<Boolean> callback);