set proxy for Android WebView, worked on api 9 ~ 19

ProxyUtils.java

package com.mcxiaoke.next.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.net.Proxy;
import android.os.Build;
import android.os.Parcelable;
import android.util.ArrayMap;
import android.util.Log;
import android.webkit.WebView;
import org.apache.http.HttpHost;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * set proxy for android webview
 * <p/>
 * Reference: http://stackoverflow.com/questions/4488338/webview-android-proxy
 * User: mcxiaoke
 * Date: 14-6-15
 * Time: 20:34
 */
public class ProxyUtils {
    public static final String LOG_TAG = ProxyUtils.class.getSimpleName();

    public static boolean setProxy(WebView webview, String host, int port, final Class<?> appClass) {
        // 3.2 (HC) or lower
        if (Build.VERSION.SDK_INT < 14) {
            return setProxyUpToHC(webview, host, port);
        }
        // ICS: 4.0
        else if (Build.VERSION.SDK_INT < 16) {
            return setProxyICS(webview, host, port);
        }
        // 4.1-4.3 (JB)
        else if (Build.VERSION.SDK_INT < 19) {
            return setProxyJB(webview, host, port);
        }
        // 4.4 (KK)
        else {
            return setProxyKK(webview, host, port, appClass.getName());
        }
    }

    /**
     * Set Proxy for Android 3.2 and below.
     */
    @SuppressWarnings("all")
    private static boolean setProxyUpToHC(WebView webview, String host, int port) {
        Log.d(LOG_TAG, "Setting proxy with <= 3.2 API.");

        HttpHost proxyServer = new HttpHost(host, port);
        // Getting network
        Class networkClass = null;
        Object network = null;
        try {
            networkClass = Class.forName("android.webkit.Network");
            if (networkClass == null) {
                Log.e(LOG_TAG, "failed to get class for android.webkit.Network");
                return false;
            }
            Method getInstanceMethod = networkClass.getMethod("getInstance", Context.class);
            if (getInstanceMethod == null) {
                Log.e(LOG_TAG, "failed to get getInstance method");
            }
            network = getInstanceMethod.invoke(networkClass, new Object[]{webview.getContext()});
        } catch (Exception ex) {
            Log.e(LOG_TAG, "error getting network: " + ex);
            return false;
        }
        if (network == null) {
            Log.e(LOG_TAG, "error getting network: network is null");
            return false;
        }
        Object requestQueue = null;
        try {
            Field requestQueueField = networkClass
                    .getDeclaredField("mRequestQueue");
            requestQueue = getFieldValueSafely(requestQueueField, network);
        } catch (Exception ex) {
            Log.e(LOG_TAG, "error getting field value");
            return false;
        }
        if (requestQueue == null) {
            Log.e(LOG_TAG, "Request queue is null");
            return false;
        }
        Field proxyHostField = null;
        try {
            Class requestQueueClass = Class.forName("android.net.http.RequestQueue");
            proxyHostField = requestQueueClass
                    .getDeclaredField("mProxyHost");
        } catch (Exception ex) {
            Log.e(LOG_TAG, "error getting proxy host field");
            return false;
        }

        boolean temp = proxyHostField.isAccessible();
        try {
            proxyHostField.setAccessible(true);
            proxyHostField.set(requestQueue, proxyServer);
        } catch (Exception ex) {
            Log.e(LOG_TAG, "error setting proxy host");
        } finally {
            proxyHostField.setAccessible(temp);
        }

        Log.d(LOG_TAG, "Setting proxy with <= 3.2 API successful!");
        return true;
    }

    @SuppressWarnings("all")
    private static boolean setProxyICS(WebView webview, String host, int port) {
        try {
            Log.d(LOG_TAG, "Setting proxy with 4.0 API.");

            Class jwcjb = Class.forName("android.webkit.JWebCoreJavaBridge");
            Class params[] = new Class[1];
            params[0] = Class.forName("android.net.ProxyProperties");
            Method updateProxyInstance = jwcjb.getDeclaredMethod("updateProxy", params);

            Class wv = Class.forName("android.webkit.WebView");
            Field mWebViewCoreField = wv.getDeclaredField("mWebViewCore");
            Object mWebViewCoreFieldInstance = getFieldValueSafely(mWebViewCoreField, webview);

            Class wvc = Class.forName("android.webkit.WebViewCore");
            Field mBrowserFrameField = wvc.getDeclaredField("mBrowserFrame");
            Object mBrowserFrame = getFieldValueSafely(mBrowserFrameField, mWebViewCoreFieldInstance);

            Class bf = Class.forName("android.webkit.BrowserFrame");
            Field sJavaBridgeField = bf.getDeclaredField("sJavaBridge");
            Object sJavaBridge = getFieldValueSafely(sJavaBridgeField, mBrowserFrame);

            Class ppclass = Class.forName("android.net.ProxyProperties");
            Class pparams[] = new Class[3];
            pparams[0] = String.class;
            pparams[1] = int.class;
            pparams[2] = String.class;
            Constructor ppcont = ppclass.getConstructor(pparams);

            updateProxyInstance.invoke(sJavaBridge, ppcont.newInstance(host, port, null));

            Log.d(LOG_TAG, "Setting proxy with 4.0 API successful!");
            return true;
        } catch (Exception ex) {
            Log.e(LOG_TAG, "failed to set HTTP proxy: " + ex);
            return false;
        }
    }

    /**
     * Set Proxy for Android 4.1 - 4.3.
     */
    @SuppressWarnings("all")
    private static boolean setProxyJB(WebView webview, String host, int port) {
        Log.d(LOG_TAG, "Setting proxy with 4.1 - 4.3 API.");

        try {
            Class wvcClass = Class.forName("android.webkit.WebViewClassic");
            Class wvParams[] = new Class[1];
            wvParams[0] = Class.forName("android.webkit.WebView");
            Method fromWebView = wvcClass.getDeclaredMethod("fromWebView", wvParams);
            Object webViewClassic = fromWebView.invoke(null, webview);

            Class wv = Class.forName("android.webkit.WebViewClassic");
            Field mWebViewCoreField = wv.getDeclaredField("mWebViewCore");
            Object mWebViewCoreFieldInstance = getFieldValueSafely(mWebViewCoreField, webViewClassic);

            Class wvc = Class.forName("android.webkit.WebViewCore");
            Field mBrowserFrameField = wvc.getDeclaredField("mBrowserFrame");
            Object mBrowserFrame = getFieldValueSafely(mBrowserFrameField, mWebViewCoreFieldInstance);

            Class bf = Class.forName("android.webkit.BrowserFrame");
            Field sJavaBridgeField = bf.getDeclaredField("sJavaBridge");
            Object sJavaBridge = getFieldValueSafely(sJavaBridgeField, mBrowserFrame);

            Class ppclass = Class.forName("android.net.ProxyProperties");
            Class pparams[] = new Class[3];
            pparams[0] = String.class;
            pparams[1] = int.class;
            pparams[2] = String.class;
            Constructor ppcont = ppclass.getConstructor(pparams);

            Class jwcjb = Class.forName("android.webkit.JWebCoreJavaBridge");
            Class params[] = new Class[1];
            params[0] = Class.forName("android.net.ProxyProperties");
            Method updateProxyInstance = jwcjb.getDeclaredMethod("updateProxy", params);

            updateProxyInstance.invoke(sJavaBridge, ppcont.newInstance(host, port, null));
        } catch (Exception ex) {
            Log.e(LOG_TAG, "Setting proxy with >= 4.1 API failed with error: " + ex.getMessage());
            return false;
        }

        Log.d(LOG_TAG, "Setting proxy with 4.1 - 4.3 API successful!");
        return true;
    }

    // from https://stackoverflow.com/questions/19979578/android-webview-set-proxy-programatically-kitkat
    @SuppressLint("NewApi")
    @SuppressWarnings("all")
    private static boolean setProxyKK(WebView webView, String host, int port, String applicationClassName) {
        Log.d(LOG_TAG, "Setting proxy with >= 4.4 API.");

        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(applicationClassName);
            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);
                    }
                }
            }

            Log.d(LOG_TAG, "Setting proxy with >= 4.4 API successful!");
            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;
    }

    private static Object getFieldValueSafely(Field field, Object classInstance) throws IllegalArgumentException, IllegalAccessException {
        boolean oldAccessibleValue = field.isAccessible();
        field.setAccessible(true);
        Object result = field.get(classInstance);
        field.setAccessible(oldAccessibleValue);
        return result;
    }
}