使用WebView监控网页加载状况，PerformanceMonitor，WebViewClient生命周期

原理：WebView加载Url完成后，注入js脚本，脚本代码使用W3C的PerformanceTimingAPI，

往js脚本传入一个Android对象(代码中为AndroidObject)，在js脚本中调用AndroidObject中的接口，以此方式将结果传回到Android代码中。

可获取的信息：

坑（注意）：

　　1、WebViewClent的onPageFinished()方法在不同的机型下会有不同的回调情况，在所测机型中魅族Pro6只会在全部网页资源加载完成以及 webView.getProgress()==100 的情况下才会回调，且只会回调一次，华为Mate7则会在所有加载网页资源尚未加载完成( webView.getProgress()<100 )时就会回调,而且即使 webView.getProgress()==100 的情况下也会回调多次，时间难以把握，此时需自己另外加判断，只有在 webView.getProgress()==100 的情况下才执行脚本，且只能执行一次。造成此种情况的原因为WebViewClent底层JNI对不同浏览器内核的适应情况较差，WebChromeClient的onProgressChanged()方法不会出现这种情况。

　　2、注入js脚本之后需要延时一段时间才能销毁WebView，否则将收不到js返回来的结果，不能在onPageFinished()中(主线程)做耗时操作，需要另外开启一个线程去做延时关闭，然后通过消息机制将销毁WebView的msg发送给Handler处理，在主线中才能销毁WebView。

　　3、在初始化WebView时是通过 WebView mWebView = new WebView(mContext); 方式，所以在销毁WebView时出现了坑，一开始是使用如下方式进行WebView销毁，但是发现run()方法不被调用，但是hasEnqueue却返回的true，查看文档发现即使在enqueue的情况下该Runnable也并不一定会调用，最后使用 mHandler = new Handler(Lopper.getMainLooper()){...} 方法解决了问题。

                 boolean hasEnqueue = mWebView.postDelayed(new Runnable() {
                     @Override
                     public void run() {
                         //didn't step into here
                         if (mWebView != null) {
                             mWebView.clearCache(true);
                             mWebView.clearHistory();
                             mWebView.destroy();
                             mWebView = null;
                         }
                     }
                 }, 500);
                 if(hasEnqueue){
                     Logger.d("the Runnable was successfully placed in to the message queue.");
                 }else{
                     Logger.d("the Runnable was failed to be placed in to the message queue.");
                 }

使用mWebView.postDelayed销毁mWebView

    Handler mHandler = new Handler(Looper.getMainLooper()) {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_DESTROY: {
                    destroyWebView();
                    break;
                }
                default:
                    super.handleMessage(msg);
            }
        }
    };

使用mHandler.handleMessage()销毁mWebView

执行结果：

     

可通过修改注入的js脚本获取更多详细信息。

代码：

         final MyWebView mWebView = new MyWebView(mContext);
         mWebView.setVisibility(View.GONE);
 
         WebSettings setting = mWebView.getSettings();
         setting.setJavaScriptEnabled(true);
         setting.setCacheMode(WebSettings.LOAD_NO_CACHE);
         setting.setLoadsImagesAutomatically(false);
 
         MyWebViewClient myWebViewClient = new MyWebViewClient();
         myWebViewClient.setTimeOut(timingCheck.getTimeout());
         mWebView.setWebViewClient(myWebViewClient);
 
         mWebView.setAndroidObject(new AndroidObject() {
             @Override
             public void handleError(String msg) {
                 Logger.d("AndroidObject,错误信息:" + msg);
             }
 
             @Override
             public void handleResource(String jsonStr) {
                 Logger.d("AndroidObject,Timing信息:" + jsonStr);
             }
         });
         mWebView.loadUrl("http:www.qq.com/");

Main.java

 import android.graphics.Bitmap;
 import android.net.http.SslError;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
 import android.webkit.SslErrorHandler;
 import android.webkit.WebResourceError;
 import android.webkit.WebResourceRequest;
 import android.webkit.WebResourceResponse;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
 import com.gomo.health.plugin.plugin.Constants;
 import com.gomo.health.plugin.utils.Logger;
 
 import java.util.Timer;
 import java.util.TimerTask;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * Created by s_x_q on 2017/4/11.
  */
 public class MyWebViewClient extends WebViewClient {
 
     private WebView mWebView;
     private AndroidObject mAndroidObject;
 
     /**
      * WebView不支持修改Timeout , 这里自定义
      */
     private int mTimeOut = 3000;
     private int mJsTimeout = 500;
 
     private Timer mTimer = new Timer();
 
     /**
      * 避免重复执行mWebsiteLoadTimeoutTask
      */
     private boolean isWebTimeoutTaskScheduling = false;
 
     /**
      * 避免重复执行mJsInjectTimeoutTask
      */
     private boolean isJsTimeoutTaskScheduling = false;
 
     /**
      * 判断网页加载是否完成
      */
     private AtomicBoolean isWebLoadFinished = new AtomicBoolean(false);
 
     private TimerTask mWebsiteLoadTimeoutTask = new TimerTask() {
         @Override
         public void run() {
             if (mWebView != null && !isWebLoadFinished.get()) {
                 sendWebsiteLoadTimeoutMsg();
             }
         }
     };
 
     private TimerTask mJsInjectTimeoutTask = new TimerTask() {
         @Override
         public void run() {
             if (mWebView != null && mAndroidObject != null) {
                 if (!mAndroidObject.isDataReturn()) {
                     sendJsInjectTimeoutMsg();
                 } else {
                     sendDestroyMsg();
                 }
             }
         }
     };
 
     final Handler handler = new Handler(Looper.getMainLooper()) {
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case Constants.HandlerMessage.MSG_DESTROY: {
                     destroyWebView();
                     break;
                 }
                 case Constants.HandlerMessage.MSG_WEBSITE_LOAD_TIMEOUT: {
                     if (mWebView != null) {
                         Logger.d("网页加载超时 , WebView进度:" + mWebView.getProgress() + " ,  url:" + mWebView.getUrl());
                         if (mWebView.getProgress() < 100) {
                             mAndroidObject.handleError("LoadUrlTimeout");
                             destroyWebView();
                         }
                     }
                     break;
                 }
                 case Constants.HandlerMessage.MSG_JS_INJECT_TIMEOUT: {
                     if (mWebView != null) {
                         if (mAndroidObject != null) {
                             if (!mAndroidObject.isDataReturn()) {
                                 Logger.d("JS注入脚本执行超时");
                                 String format = "ExecuteJsTimeout(%dms)";
                                 mAndroidObject.handleError(String.format(format, mJsTimeout));
                                 destroyWebView();
                             }
                         }
                     }
                     break;
                 }
 
                 default:
                     super.handleMessage(msg);
             }
         }
     };
 
     @Override
     public void onPageStarted(WebView view, String url, Bitmap favicon) {
         super.onPageStarted(view, url, favicon);
         Logger.d("网页开始加载:" + url);
 
         if (mWebView == null) {
             mWebView = view;
             if (mWebView instanceof MyWebView) {
                 mAndroidObject = ((MyWebView) mWebView).getAndroidObject();
             }
         }
         setupWebLoadTimeout();
     }
 
     @Override
     public boolean shouldOverrideUrlLoading(WebView view, String url) {
         //只会重定向时回调,然后回调onPageStarted
 //        Logger.d("回调旧版shouldOverrideUrlLoading ， url :" + url);
         return super.shouldOverrideUrlLoading(view, url);
     }
 
     @Override
     public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
         //只会重定向时回调,然后回调onPageStarted
 //        Logger.d("回调新版shouldOverrideUrlLoading ， request method :" + request.getMethod() + "\t是否为重定向: " + request.isRedirect() + "\trequest url :" + request.getUrl());
         return super.shouldOverrideUrlLoading(view, request);
     }
 
     @Override
     public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
         //每次请求资源的时候都会在onLoadResource前回调，可用于拦截资源加载，修改request
 //        Logger.d("回调旧版shouldInterceptRequest ， url :" + url);
         return super.shouldInterceptRequest(view, url);
     }
 
     @Override
     public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
         //每次请求资源的时候都会在onLoadResource前回调，可用于拦截资源加载，修改request
 //        Logger.d("回调新版shouldInterceptRequest " );
         return super.shouldInterceptRequest(view, request);
     }
 
     @Override
     public void onLoadResource(WebView view, String url) {
         super.onLoadResource(view, url);
 //        Logger.d("加载网页资源 , url:" + url + " , WebView进度:" + view.getProgress());
     }
 
     public void onPageFinished(WebView view, String url) {
         super.onPageFinished(view, url);
 
         Logger.d("网页加载完成,WebView进度:" + view.getProgress());
 
         //可能会在进度<100或==100的情况下出现多次onPageFinished回调
         if (view.getProgress() == 100 && !isWebLoadFinished.get()) {
             Logger.d("注入js脚本");
             //可能会回调多次
             isWebLoadFinished.set(true);
             String format = "javascript:%s.sendResource(JSON.stringify(window.performance.timing));";
             String injectJs = String.format(format, MyWebView.ANDROID_OBJECT_NAME);
             view.loadUrl(injectJs);
 
             setupJsInjectTimeout();
         }
     }
 
     @Deprecated
     @Override
     public void onReceivedError(WebView view, int errorCode,
                                 String description, String failingUrl) {
         super.onReceivedError(view, errorCode, description, failingUrl);
         Logger.d("回调旧版本onReceivedError():" + "错误描述:" + description + "\t错误代码:" + errorCode + "失败的Url:" + failingUrl);
 
         handleError(description);
     }
 
     @Override
     public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
         super.onReceivedError(view, request, error);
         Logger.d("回调新版本onReceivedError:");
     }
 
     @Override
     public void onReceivedHttpError(WebView view, WebResourceRequest request, WebResourceResponse errorResponse) {
         super.onReceivedHttpError(view, request, errorResponse);
         Logger.d("回调onRecivedHttpError:");
         handleError("onReceivedHttpError");
     }
 
     @Override
     public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
         super.onReceivedSslError(view, handler, error);
         Logger.d("回调onReceivedSslError()：" + "\terror:" + error.toString());
         handleError("onReceivedSslError");
     }
 
     private void handleError(String msg) {
         isWebLoadFinished.set(true);
         sendDestroyMsg();
         if (mAndroidObject != null) {
             mAndroidObject.handleError(msg);
         }
 
     }
 
     public int getTimeOut() {
         return mTimeOut;
     }
 
     public void setTimeOut(int timeOut) {
         mTimeOut = timeOut;
     }
 
     /**
      * 网页加载计时
      */
     private void setupWebLoadTimeout() {
         if (!isWebTimeoutTaskScheduling) {
             isWebTimeoutTaskScheduling = true;
             mTimer.schedule(mWebsiteLoadTimeoutTask, mTimeOut);
         }
     }
 
     /**
      * 注入js脚本执行计时
      * <p>
      * 注入js之后等待一段时间，如果这段时间内js不回调AndroidObject.handleResource()，则再销毁WebView
      * 过早销毁WebView，js不回调AndroidObject.handleResource()
      */
     private void setupJsInjectTimeout() {
         if (!isJsTimeoutTaskScheduling) {
             isJsTimeoutTaskScheduling = true;
             if (mAndroidObject != null) {
                 mAndroidObject.setStartTime(System.currentTimeMillis());
             }
             mTimer.schedule(mJsInjectTimeoutTask, mJsTimeout);
         }
     }
 
     private void sendDestroyMsg() {
         handler.sendEmptyMessage(Constants.HandlerMessage.MSG_DESTROY);
     }
 
     private void sendWebsiteLoadTimeoutMsg() {
         handler.sendEmptyMessage(Constants.HandlerMessage.MSG_WEBSITE_LOAD_TIMEOUT);
     }
 
     private void sendJsInjectTimeoutMsg() {
         handler.sendEmptyMessage(Constants.HandlerMessage.MSG_JS_INJECT_TIMEOUT);
     }
 
     private void destroyWebView() {
         if (mWebView != null) {
             mWebView.clearCache(true);
             mWebView.clearHistory();
             mWebView.destroy();
             mWebView = null;
             Logger.d("成功销毁WebView");
         } else {
             Logger.d("销毁失败，WebView为空");
         }
     }
 
 }

MyWebViewClient.java

 import android.webkit.JavascriptInterface;
 
 /**
  * Created by s_x_q on 2017/4/11.
  */
 
 public abstract class AndroidObject {
 
     private volatile boolean mIsDataReturn = false ;
     private long startTime ;
     private long endTime ;
 
     /**
      *用于收集Timing信息
      *
      * @param jsonStr
      */
     @JavascriptInterface
     public void sendResource(String jsonStr) {
         mIsDataReturn = true ;
         endTime = System.currentTimeMillis();
         Logger.d("js成功执行时间：" + (endTime-startTime));
         handleResource(jsonStr);
     }
 
     /**
      * 用于收集js的执行错误
      * @param msg
      */
     @JavascriptInterface
     public void sendError(String msg) {
         handleError(msg);
     }
 
     /**
      * 处理错误信息，可能会被回调多次
      * @param msg
      */
     public abstract void handleError(String msg) ;
 
     /**
      *
      * @param jsonStr
      */
     public abstract void handleResource(String jsonStr);
 
     public boolean isDataReturn() {
         return mIsDataReturn;
     }
 
     public long getStartTime() {
         return startTime;
     }
 
     public void setStartTime(long startTime) {
         this.startTime = startTime;
     }
 
     public long getEndTime() {
         return endTime;
     }
 
     public void setEndTime(long endTime) {
         this.endTime = endTime;
     }
 }

AndroidObject.java

package com.sxq.webviewperformancemonitor;
 
import android.content.Context;
import android.util.AttributeSet;
import android.webkit.WebView;
 
/**
 * Created by shixiaoqiangsx on 2017/4/11.
 */
public class MyWebView extends WebView {
 
    public final static String ANDROID_OBJECT_NAME = "android";
 
    private AndroidObject mAndroidObject = null;
 
    public MyWebView(Context context) {
        this(context, null, 0);
    }
 
    public MyWebView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
 
    public MyWebView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }
 
    public void setAndroidObject(AndroidObject object) {
        if (object == null) {
            Logger.d("AndroidObject can not be null !");
            this.mAndroidObject = new AndroidObject() {
                @Override
                public void handleError(String msg) {
                }
 
                @Override
                public void handleResource(String jsonStr) {
                }
            };
        } else {
            this.mAndroidObject = object;
        }
 
        super.addJavascriptInterface(mAndroidObject, ANDROID_OBJECT_NAME);
    }
 
    protected AndroidObject getAndroidObject() {
        return this.mAndroidObject;
    }
}

MyWebView.java

项目地址：

WebViewPerformanceMonitor

拓展：

Performance Timing API :

W3C：A Primer for Web Performance Timing APIs

Google：测量资源加载时间

Google：了解资源耗时

W3C：Resource Timing Level 3

WebView开发：

WebView开发之坑

WebView拦截过滤Url:

GoogleChrome高级WebView应用实例,官方Chromium WebView Sample

Android 拦截WebView加载URL，控制其加载CSS、JS资源，WebView缓存

Webview资源请求的拦截

Android中WebView中拦截所有请求并替换URL