I’m developping an Android application filtering the requests (with a white list) and using a custom SSLSocketFactory. For this, I’ve developed a custom WebViewClient and I have overridden the shouldInterceptRequest method. I can filter and use my SocketFactory with the GET requests but I can’t intercept the POST requests.
So, is there a way to intercept the POST requests in a WebView ?
Here is the code of the shouldInterceptRequest method :
public final WebResourceResponse shouldInterceptRequest(WebView view, String urlStr) {
URI uri = URI.create(urlStr);
String scheme = uri.getScheme();
// If scheme not http(s), let the default webview manage it
if(!"http".equals(scheme) && !"https".equals(scheme)) {
return null;
}
URL url = uri.toURL();
if(doCancelRequest(url)) {
// Empty response
Log.d(TAG, "URL filtered: " + url);
return new WebResourceResponse("text/plain", "UTF-8", new EmptyInputStream());
} else {
Log.d(TAG, "URL: " + url);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestProperty("User-Agent", mSettings.getUserAgentString());
// Configure connections
configureConnection(conn);
String mimeType = conn.getContentType();
String encoding = conn.getContentEncoding();
if(mimeType != null && mimeType.contains(CONTENT_TYPE_SPLIT)) {
String[] split = mimeType.split(CONTENT_TYPE_SPLIT);
mimeType = split[0];
Matcher matcher = CONTENT_TYPE_PATTERN.matcher(split[1]);
if(matcher.find()) {
encoding = matcher.group(1);
}
}
InputStream is = conn.getInputStream();
return new WebResourceResponse(mimeType, encoding, is);
}
}
I was facing the same issue a few days ago.
So I built a library that solves it:
https://github.com/KonstantinSchubert/request_data_webviewclient
It is a WebViewClient with a custom WebResourceRequest that contains the POST/PUT/… payload of XMLHttpRequest requests.
It only works for these though – not for forms and other kind of request sources.
The hack works, basically, by injecting a script into the HTML that intercepts XMLHttpRequest calls. It records the post/put/… content and sends it to an android.webkit.JavascriptInterface. There, the request is stashed until the shouldInterceptRequest method is called by Android …
Answer：
you can get input value before submit
https://github.com/henrychuangtw/WebView-Javascript-Inject
Step 1 : create a class which called by javascript
class MyJavaScriptInterface
{
@JavascriptInterface
public void processHTML(String html)
{
//called by javascript
}
}
Step 2 : register interface for javascript
webview1.getSettings().setJavaScriptEnabled(true);
webview1.addJavascriptInterface(new MyJavaScriptInterface(), "MYOBJECT");
Step 3 : inject javascript to page
webview1.setWebViewClient(new WebViewClient() {
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
StringBuilder sb = new StringBuilder();
sb.append("document.getElementsByTagName('form')[0].onsubmit = function () {");
sb.append("var objPWD, objAccount;var str = '';");
sb.append("var inputs = document.getElementsByTagName('input');");
sb.append("for (var i = 0; i < inputs.length; i++) {");
sb.append("if (inputs[i].type.toLowerCase() === 'password') {objPWD = inputs[i];}");
sb.append("else if (inputs[i].name.toLowerCase() === 'email') {objAccount = inputs[i];}");
sb.append("}");
sb.append("if (objAccount != null) {str += objAccount.value;}");
sb.append("if (objPWD != null) { str += ' , ' + objPWD.value;}");
sb.append("window.MYOBJECT.processHTML(str);");
sb.append("return true;");
sb.append("};");
view.loadUrl("javascript:" + sb.toString());
}
});
Answer：
Use GET instead of POST.
Known issue:
http://code.google.com/p/android/issues/detail?id=9122
Was answered here as well:
Android – how to intercept a form POST in android WebViewClient on API level 4
Answer：
I have one of my answers on above thread http://code.google.com/p/android/issues/detail?id=9122
Please see comment#31
Some of the caveats of my solution I see are:
- Putting a dependency on xmlhttprequest prototype which has different implementation for different webkits.
- Security issue in sending data for post requests in URL. But I guess you can solve that through some encryption mechanism.
- URL length issue for some of the browsers if you big data to post
Apart from that, I found this github repo which seems to be solving this problem in another hacky way. I looked into the code but didn’t get time to implement and test it. But worth giving a try.
Tags: androidandroid, post, view, webview
