android的WebKit上的JS直接使用Java Bean

public class Bean{
    private String title;

    public void setTitle(String title){
        this.title = title;
    }

    public String getTitle(){
        return this.title;
    }
}

package com.xu81.tw4a;

import java.util.List;

import android.app.Activity;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;

public class TiddlyWiki4Android extends Activity {

    private WebView mainWebView;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
                
                //webview对象
        mainWebView = (WebView) findViewById(R.id.mainWebView);

        WebSettings setting = mainWebView.getSettings();
        setting.setJavaScriptEnabled(true);//允许javascript
        mainWebView.setWebChromeClient(new WebChromeClient());//初始化WebChromeClient对象
                Bean b = new Bean();
                b.setTitle("title");
        mainWebView.addJavascriptInterface(b, "bean");//添加javascript对象
        mainWebView.loadUrl("file:///android_asset/test.html");//加载本地html页面
    }
}

function getDefault(){
    var bean = window.bean;
    var title = bean.getTitle();
        alert(title);
}