Android Webview set proxy programmatically Kitkat

Question

How can we set proxy in Android webview programmatically on latest Kitkat release?

This SO link WebView android proxy talks about version upto SDK version 18. But those solution no more works with Kitkat as underlying webkit implementation is changed and it uses chromium now.

Answer 1

Here is my solution:

public static void setKitKatWebViewProxy(Context appContext, String host, int port) {
    System.setProperty("http.proxyHost", host);
    System.setProperty("http.proxyPort", port + "");
    System.setProperty("https.proxyHost", host);
    System.setProperty("https.proxyPort", port + "");
    try {
        Class applictionCls = Class.forName("android.app.Application");
        Field loadedApkField = applictionCls.getDeclaredField("mLoadedApk");
        loadedApkField.setAccessible(true);
        Object loadedApk = loadedApkField.get(appContext);
        Class loadedApkCls = Class.forName("android.app.LoadedApk");
        Field receiversField = loadedApkCls.getDeclaredField("mReceivers");
        receiversField.setAccessible(true);
        ArrayMap receivers = (ArrayMap) receiversField.get(loadedApk);
        for (Object receiverMap : receivers.values()) {
            for (Object rec : ((ArrayMap) receiverMap).keySet()) {
                Class clazz = rec.getClass();
                if (clazz.getName().contains("ProxyChangeListener")) {
                    Method onReceiveMethod = clazz.getDeclaredMethod("onReceive", Context.class, Intent.class);
                    Intent intent = new Intent(Proxy.PROXY_CHANGE_ACTION);

                    /*********** optional, may be need in future *************/
                    final String CLASS_NAME = "android.net.ProxyProperties";
                    Class cls = Class.forName(CLASS_NAME);
                    Constructor constructor = cls.getConstructor(String.class, Integer.TYPE, String.class);
                    constructor.setAccessible(true);
                    Object proxyProperties = constructor.newInstance(host, port, null);
                    intent.putExtra("proxy", (Parcelable) proxyProperties);
                    /*********** optional, may be need in future *************/

                    onReceiveMethod.invoke(rec, appContext, intent);
                }
            }
        }
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (NoSuchFieldException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (NoSuchMethodException e) {
        e.printStackTrace();
    } catch (InvocationTargetException e) {
        e.printStackTrace();
    } catch (InstantiationException e) {
        e.printStackTrace();
    }
}

I hope it can help you.

Note: The Context parameter should be an Application context as the parameter name showed, you could use your own implemented Application instance which extend Application.

Answer 2

I've made some changes to @xjy2061's answer.

Changes are:

1. getDeclaredField to getField --> You use this if you declared your own application class. Else it won't find it.

Also, remember to change "com.your.application" to your own application's class canonical name.

private static boolean setKitKatWebViewProxy(WebView webView, String host, int port) {
    Context appContext = webView.getContext().getApplicationContext();
    System.setProperty("http.proxyHost", host);
    System.setProperty("http.proxyPort", port + "");
    System.setProperty("https.proxyHost", host);
    System.setProperty("https.proxyPort", port + "");
    try {
        Class applictionCls = Class.forName("acr.browser.barebones.Jerky");
        Field loadedApkField = applictionCls.getField("mLoadedApk");
        loadedApkField.setAccessible(true);
        Object loadedApk = loadedApkField.get(appContext);
        Class loadedApkCls = Class.forName("android.app.LoadedApk");
        Field receiversField = loadedApkCls.getDeclaredField("mReceivers");
        receiversField.setAccessible(true);
        ArrayMap receivers = (ArrayMap) receiversField.get(loadedApk);
        for (Object receiverMap : receivers.values()) {
            for (Object rec : ((ArrayMap) receiverMap).keySet()) {
                Class clazz = rec.getClass();
                if (clazz.getName().contains("ProxyChangeListener")) {
                    Method onReceiveMethod = clazz.getDeclaredMethod("onReceive", Context.class, Intent.class);
                    Intent intent = new Intent(Proxy.PROXY_CHANGE_ACTION);

                    /*********** optional, may be need in future *************/
                    final String CLASS_NAME = "android.net.ProxyProperties";
                    Class cls = Class.forName(CLASS_NAME);
                    Constructor constructor = cls.getConstructor(String.class, Integer.TYPE, String.class);
                    constructor.setAccessible(true);
                    Object proxyProperties = constructor.newInstance(host, port, null);
                    intent.putExtra("proxy", (Parcelable) proxyProperties);
                    /*********** optional, may be need in future *************/

                    onReceiveMethod.invoke(rec, appContext, intent);
                }
            }
        }
        return true;
    } catch (ClassNotFoundException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (NoSuchFieldException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (IllegalAccessException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (IllegalArgumentException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (NoSuchMethodException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (InvocationTargetException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    } catch (InstantiationException e) {
        StringWriter sw = new StringWriter();
        e.printStackTrace(new PrintWriter(sw));
        String exceptionAsString = sw.toString();
        Log.v(LOG_TAG, e.getMessage());
        Log.v(LOG_TAG, exceptionAsString);
    }
    return false;
}

Answer 3

I am creating a cordova android application, and couldn't figure out why ajax requests to internal hosts on my company's network were failing on KitKat. All native web requests succeeded, and all ajax requests on android versions below 4.4 succeeded aswell. The ajax requests only failed when on the internal company wifi which was even more perplexing.

Turns out KitKat uses a new chrome webview which is different from the standard webviews used in previous android versions. There is a bug in the version of chromium that kitkat uses where it doesn't respect the proxy exclusion list. Our company wifi sets a proxy server, and and excludes all internal hosts. The ajax requests were ultimately failing because authentication to the proxy was failing. Since these requests are to internal hosts, it should have never been going through the proxy to begin with. I was able to adapt xjy2061's answer to fit my usecase.

Hopefully this helps someone in the future and saves them a few days of head banging.

//Set KitKat proxy w/ proxy exclusion.    
@TargetApi(Build.VERSION_CODES.KITKAT)
public static void setKitKatWebViewProxy(Context appContext, String host, int port, String exclusionList) {

    Properties properties = System.getProperties();
    properties.setProperty("http.proxyHost", host);
    properties.setProperty("http.proxyPort", port + "");
    properties.setProperty("https.proxyHost", host);
    properties.setProperty("https.proxyPort", port + "");
    properties.setProperty("http.nonProxyHosts", exclusionList);
    properties.setProperty("https.nonProxyHosts", exclusionList);

    try {
        Class applictionCls = Class.forName("android.app.Application");
        Field loadedApkField = applictionCls.getDeclaredField("mLoadedApk");
        loadedApkField.setAccessible(true);
        Object loadedApk = loadedApkField.get(appContext);
        Class loadedApkCls = Class.forName("android.app.LoadedApk");
        Field receiversField = loadedApkCls.getDeclaredField("mReceivers");
        receiversField.setAccessible(true);
        ArrayMap receivers = (ArrayMap) receiversField.get(loadedApk);
        for (Object receiverMap : receivers.values()) {
            for (Object rec : ((ArrayMap) receiverMap).keySet()) {
                Class clazz = rec.getClass();
                if (clazz.getName().contains("ProxyChangeListener")) {
                    Method onReceiveMethod = clazz.getDeclaredMethod("onReceive", Context.class, Intent.class);
                    Intent intent = new Intent(Proxy.PROXY_CHANGE_ACTION);

                    /*********** optional, may be need in future *************/
                    final String CLASS_NAME = "android.net.ProxyProperties";
                    Class cls = Class.forName(CLASS_NAME);
                    Constructor constructor = cls.getConstructor(String.class, Integer.TYPE, String.class);
                    constructor.setAccessible(true);
                    Object proxyProperties = constructor.newInstance(host, port, exclusionList);
                    intent.putExtra("proxy", (Parcelable) proxyProperties);
                    /*********** optional, may be need in future *************/

                    onReceiveMethod.invoke(rec, appContext, intent);
                }
            }
        }
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (NoSuchFieldException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (NoSuchMethodException e) {
        e.printStackTrace();
    } catch (InvocationTargetException e) {
        e.printStackTrace();
    } catch (InstantiationException e) {
        e.printStackTrace();
    }
}

You would call the method above as follows:

First import this library at the top of your file.

import android.util.ArrayMap;

Then call the method

int currentapiVersion = android.os.Build.VERSION.SDK_INT;
//check first to see if we are running KitKat
if (currentapiVersion >= Build.VERSION_CODES.KITKAT){
    setKitKatWebViewProxy(context, proxy, port, exclusionList);
}