<uses-permission android:name="android.permission.INTERNET" />

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

    <WebView
        android:id="@+id/webView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

package com.yangshidesign.testgryoscope;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.webkit.JavascriptInterface;
import android.webkit.WebView;
import android.widget.Toast;

public class AddEmojiActivity extends Activity {
 private WebView webView;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  this.setContentView(R.layout.activity_addemoji);
  
  webView = (WebView) this.findViewById(R.id.webView1);
  
  webView.getSettings().setJavaScriptEnabled(true);
  webView.addJavascriptInterface(new WebPlugin(), "WebPlugin");
  
  webView.loadUrl(this.getString(R.string.server_url));
 }
 
 /**
  * 插件類，在html的js里面直接調用
  */
 private class WebPlugin {
  
  @JavascriptInterface
  public void test() {
   Log.e("miquan", "kkkkkk");
   Toast.makeText(AddEmojiActivity.this, "test toast ", Toast.LENGTH_SHORT).show();
  }
  
  @JavascriptInterface
  public String test2() {
   return "something";
  }
 }
}

<script type="text/javascript">
 function test() {
  WebPlugin.test();
  var something = WebPlugin.test2();
 }
</script>