註冊自定義 WebViewClient

package com.j2ko.webviewapp;

import android.graphics.Bitmap;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.webkit.WebResourceRequest;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        WebView webView = (WebView) findViewById(R.id.webview);
        webView.setWebViewClient(new WebViewClient(){
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                Log.d(TAG, "onPageStarted: with url " + url);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                Log.d(TAG, "onPageFinished: for " + url);
            }

            @Override
            public void onPageCommitVisible(WebView view, String url) {
                super.onPageCommitVisible(view, url);
                Log.d(TAG, "onPageCommitVisible: for " + url);
            }

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                Log.d(TAG, "shouldOverrideUrlLoading: for " + url);
                return super.shouldOverrideUrlLoading(view, url);
            }

            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                Log.d(TAG, "shouldOverrideUrlLoading: for " +  request.getUrl());
                return super.shouldOverrideUrlLoading(view, request);
            }

            @Override
            public void onLoadResource(WebView view, String url) {
                super.onLoadResource(view, url);
                Log.d(TAG, "onLoadResource: " + url);
            }
        });
        webView.loadUrl("http://stackoverflow.com/");
    }
}

輸出：

D/MainActivity: onPageStarted: with url http://stackoverflow.com/
D/MainActivity: onLoadResource: http://stackoverflow.com/
D/MainActivity: onLoadResource: https://cdn.sstatic.net/Sites/stackoverflow/mobile.css?v=88186b623ab1
D/MainActivity: onPageFinished: for http://stackoverflow.com/
D/MainActivity: onLoadResource: https://cdn.sstatic.net/Sites/stackoverflow/img/favicon.ico?v=4f32ecc8f43d
D/MainActivity: onPageCommitVisible: for http://stackoverflow.com/