前言：常常遇到要展示一个普通的网页的功能，这个类应该合适基本的简单的展示需求了。

package com.zuji.entrance.activity;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.ViewGroup;
import android.webkit.GeolocationPermissions;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.LinearLayout;

import com.zuji.library.R;

/**
 * Created by fangyc on 2018/7/23.
 */

public class Html5Activity extends AppCompatActivity {

    private String mUrl;

    private LinearLayout mLayout;
    private WebView mWebView;

    public static void startActivity(Activity context, String url) {
        if (context != null) {
            Intent intent = new Intent(context, Html5Activity.class);
            Bundle bundle = new Bundle();
            bundle.putString("url", url);
            intent.putExtras(bundle);
            context.startActivity(intent);
        }
    }

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

        Bundle bundle = getIntent().getExtras();
        mUrl = bundle.getString("url");
        mLayout = (LinearLayout) findViewById(R.id.web_layout);

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        mWebView = new WebView(getApplicationContext());
        mWebView.setLayoutParams(params);
        mLayout.addView(mWebView);

        WebSettings mWebSettings = mWebView.getSettings();
        mWebSettings.setSupportZoom(true);
        mWebSettings.setLoadWithOverviewMode(true);
        mWebSettings.setUseWideViewPort(true);
        mWebSettings.setDefaultTextEncodingName("utf-8");
        mWebSettings.setLoadsImagesAutomatically(true);

        //调用JS方法.安卓版本大于17,加上注解 @JavascriptInterface
        mWebSettings.setJavaScriptEnabled(true);

        saveData(mWebSettings);

        newWin(mWebSettings);

        mWebView.setWebChromeClient(webChromeClient);
        mWebView.setWebViewClient(webViewClient);
        mWebView.loadUrl(mUrl);
    }

    @Override
    public void onPause() {
        super.onPause();
        mWebView.onPause();
        mWebView.pauseTimers(); //小心这个！！！暂停整个 WebView 所有布局、解析、JS。
    }

    @Override
    public void onResume() {
        super.onResume();
        mWebView.onResume();
        mWebView.resumeTimers();
    }

    /**
     * 多窗口的问题
     */
    private void newWin(WebSettings mWebSettings) {
        //html中的_bank标签就是新建窗口打开，有时会打不开，需要加以下
        //然后 复写 WebChromeClient的onCreateWindow方法
        mWebSettings.setSupportMultipleWindows(false);
        mWebSettings.setJavaScriptCanOpenWindowsAutomatically(true);
    }

    /**
     * HTML5数据存储
     */
    private void saveData(WebSettings mWebSettings) {
        //有时候网页需要自己保存一些关键数据,Android WebView 需要自己设置
        mWebSettings.setDomStorageEnabled(true);
        mWebSettings.setDatabaseEnabled(true);
        mWebSettings.setAppCacheEnabled(true);
        String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
        mWebSettings.setAppCachePath(appCachePath);
    }

    WebViewClient webViewClient = new WebViewClient() {

        /**
         * 多页面在同一个WebView中打开，就是不新建activity或者调用系统浏览器打开
         */
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }

    };

    WebChromeClient webChromeClient = new WebChromeClient() {

        //=========HTML5定位==========================================================
        //需要先加入权限
        //<uses-permission android:name="android.permission.INTERNET"/>
        //<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
        //<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
        @Override
        public void onReceivedIcon(WebView view, Bitmap icon) {
            super.onReceivedIcon(view, icon);
        }

        @Override
        public void onGeolocationPermissionsHidePrompt() {
            super.onGeolocationPermissionsHidePrompt();
        }

        @Override
        public void onGeolocationPermissionsShowPrompt(final String origin, final GeolocationPermissions.Callback callback) {
            callback.invoke(origin, true, false);//注意个函数，第二个参数就是是否同意定位权限，第三个是是否希望内核记住
            super.onGeolocationPermissionsShowPrompt(origin, callback);
        }
        //=========HTML5定位==========================================================

        //=========多窗口的问题==========================================================
        @Override
        public boolean onCreateWindow(WebView view, boolean isDialog, boolean isUserGesture, Message resultMsg) {
            WebView.WebViewTransport transport = (WebView.WebViewTransport) resultMsg.obj;
            transport.setWebView(view);
            resultMsg.sendToTarget();
            return true;
        }
        //=========多窗口的问题==========================================================
    };

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack()) {
            mWebView.goBack();
            return true;
        }

        return super.onKeyDown(keyCode, event);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if (mWebView != null) {
            mWebView.clearHistory();
            ((ViewGroup) mWebView.getParent()).removeView(mWebView);
            mWebView.loadUrl("about:blank");
            mWebView.stopLoading();
            mWebView.setWebChromeClient(null);
            mWebView.setWebViewClient(null);
            mWebView.destroy();
            mWebView = null;
        }
    }

}

activity_web.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/web_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

</LinearLayout>

感谢：
史上最全webview详解