问Android webview和localStorage

EN

package com.test.HelloWebView; 
import android.app.Activity; 
import android.content.Context; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.KeyEvent; 
import android.webkit.WebChromeClient; 
import android.webkit.WebSettings; 
import android.webkit.WebStorage; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 

public class HelloWebView extends Activity { 

    WebView webview;

    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main); 
        webview = (WebView) findViewById(R.id.webview); 
        webview.getSettings().setJavaScriptEnabled(true); 
        webview.setWebViewClient(new HelloWebViewClient()); 
        webview.loadUrl("file:///android_asset/test.html"); 
        WebSettings settings = webview.getSettings(); 
        settings.setJavaScriptEnabled(true); 
        settings.setDatabaseEnabled(true); 
        String databasePath = this.getApplicationContext().getDir("database", Context.MODE_PRIVATE).getPath(); 
        settings.setDatabasePath(databasePath);
        webview.setWebChromeClient(new WebChromeClient() { 
        public void onExceededDatabaseQuota(String url, String databaseIdentifier, long currentQuota, long estimatedSize, long totalUsedQuota, WebStorage.QuotaUpdater quotaUpdater) { 
                quotaUpdater.updateQuota(5 * 1024 * 1024); 
            } 
        }); 
    }

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

    private class HelloWebViewClient extends WebViewClient { 
        public boolean shouldOverrideUrlLoading(WebView view, String url) { 
            view.loadUrl(url); 
            return true; 
        } 
    }
}