package com.example.helloweb;import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebSettings;
import android.webkit.WebStorage.QuotaUpdater;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);// 为了支持HTML5使用数据库(sqlite)的本地存储String databasePath = getApplicationContext().getDir("database", Context.MODE_PRIVATE).getPath();if (savedInstanceState == null) {PlaceholderFragment fragment = new PlaceholderFragment();fragment.setDatabasePath(databasePath);getFragmentManager().beginTransaction().add(R.id.container, fragment).commit();}}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}/*** A placeholder fragment containing a simple view.* 被实例化，作为子UI的类*/public static class PlaceholderFragment extends Fragment {String databasePath;public PlaceholderFragment() {    }// 拿到MainActivity生成的数据库路径public void setDatabasePath(String databasePath){this.databasePath = databasePath;}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {View rootView = inflater.inflate(R.layout.fragment_main, container, false);// 通过IDE在子UI里拖进去一个webView,所以这里从rootView里查找WebView  webView = (WebView)rootView.findViewById(R.id.webView1);webView.setWebChromeClient(this.makeWebChromeClient());WebSettings webSettings = webView.getSettings();       webSettings.setJavaScriptEnabled(true);webSettings.setDatabaseEnabled(true);webSettings.setDatabasePath(this.databasePath);// 可以加载本地和网络的资源，加载网络资源需要配置权限//webView.loadUrl("http://www.csdn.net/");webView.loadUrl("file:///android_asset/demo.html");   return rootView;}private WebChromeClient makeWebChromeClient(){return new WebChromeClient(){@Overridepublic void onExceededDatabaseQuota(String url,String databaseIdentifier,long currentQuota,long estimatedSize,long totalUsedQuota,QuotaUpdater quotaUpdater) {quotaUpdater.updateQuota(5 * 1024 * 1024);}};}   }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest><uses-permission android:name="android.permission.INTERNET" /> 

    <uses-sdk/><application></application></manifest>

webSettings.setDatabasePath(this.databasePath);
webSettings.setDomStorageEnabled(true);