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);
}