教你如何开关Android的APN网络

由于Android对于APN的网络API没有公开，不过我们可以阅读源代码，然后进行数据库操作，系统会自动监听数据库的变化，从而实现开启或者关闭APN。

大家可以研究一下frameworks/base/core/java/android/provider/Telephony.java这个类，

比较重要的就是 URI 和数据库字段： content://telephony/carriers

字段可以在Telephony.java中找到。

其实原理很简单 ： 

1 、 当开启APN的时候，设置一个正确的移动或者联通的APN

2、 关闭的时候设置一个错误APN就会自动关闭网络

请看代码：Activity：

package cc.mdev.apn;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;


/**
 * 這裡是Activity
 * @author SinFrancis wong
 * @site http://mdev.cc
 * @wiki http://mdev.cc/wiki
 * @since 2010-01-08
 */
public class Main extends Activity {
    /** Called when the activity is first created. */
    Uri uri = Uri.parse("content://telephony/carriers");
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button open= (Button) findViewById(R.id.open);
        Button close= (Button) findViewById(R.id.close);

        open.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                openAPN();
            }
        });


        close.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                closeAPN();
            }
        });

    }

    public  void openAPN(){

        List<APN> list = getAPNList();
        for (APN apn : list) {
            ContentValues cv = new ContentValues();
            cv.put("apn", APNMatchTools.matchAPN(apn.apn));
            cv.put("type", APNMatchTools.matchAPN(apn.type));
            getContentResolver().update(uri, cv, "_id=?", new String[]{apn.id});

        }
    }

    public void closeAPN(){
        List<APN> list = getAPNList();
        for (APN apn : list) {
            ContentValues cv = new ContentValues();
            cv.put("apn", APNMatchTools.matchAPN(apn.apn)+"mdev");
            cv.put("type", APNMatchTools.matchAPN(apn.type)+"mdev");
            getContentResolver().update(uri, cv, "_id=?", new String[]{apn.id});

        }
    }

    private List<APN> getAPNList(){
        String tag = "Main.getAPNList()";

        //current不为空表示可以使用的APN
        String  projection[] = {"_id,apn,type,current"};
        Cursor cr = this.getContentResolver().query(uri, projection, null, null, null);

        List<APN> list = new ArrayList<APN>();

        while(cr!=null && cr.moveToNext()){
            Log.d(tag, cr.getString(cr.getColumnIndex("_id")) + "  " + cr.getString(cr.getColumnIndex("apn")) + "  " + cr.getString(cr.getColumnIndex("type"))+ "  " + cr.getString(cr.getColumnIndex("current")));
            APN a = new APN();
            a.id = cr.getString(cr.getColumnIndex("_id"));
            a.apn = cr.getString(cr.getColumnIndex("apn"));
            a.type = cr.getString(cr.getColumnIndex("type"));
            list.add(a);
        }
        if(cr!=null)
        cr.close();
        return list;
    }


    public static class APN{
        String id;
        String apn;
        String type;
    }

}

APNMatchTools.java

package cc.mdev.apn;



/**
 * 這裡是APN匹配，用於匹配移動或者聯通的APN
 * @author SinFrancis wong
 * @site http://mdev.cc
 * @wiki http://mdev.cc/wiki
 * @since 2010-01-08
 *
 */
public final class APNMatchTools {

    public static class APNNet{
        /**
         * 中国移动cmwap
         */
        public static String CMWAP = "cmwap";

        /**
         * 中国移动cmnet
         */
        public static String CMNET = "cmnet";

        //中国联通3GWAP设置        中国联通3G因特网设置        中国联通WAP设置        中国联通因特网设置
        //3gwap                 3gnet                uniwap            uninet


        /**
         * 3G wap 中国联通3gwap APN
         */
        public static String GWAP_3 = "3gwap";

        /**
         * 3G net 中国联通3gnet APN
         */
        public static String GNET_3="3gnet";

        /**
         * uni wap 中国联通uni wap APN
         */
        public static String UNIWAP="uniwap";
        /**
         * uni net 中国联通uni net APN
         */
        public static String UNINET="uninet";
    }



    public static String matchAPN(String currentName) {
        if("".equals(currentName) || null==currentName){
            return "";
        }
        currentName = currentName.toLowerCase();
        if(currentName.startsWith(APNNet.CMNET))
            return APNNet.CMNET;
        else if(currentName.startsWith(APNNet.CMWAP))
            return APNNet.CMWAP;
        else if(currentName.startsWith(APNNet.GNET_3))
            return APNNet.GNET_3;
        else if(currentName.startsWith(APNNet.GWAP_3))
            return APNNet.GWAP_3;
        else if(currentName.startsWith(APNNet.UNINET))
            return APNNet.UNINET;
        else if(currentName.startsWith(APNNet.UNIWAP))
            return APNNet.UNIWAP;
        else if(currentName.startsWith("default"))
            return "default";
        else return "";
       // return currentName.substring(0, currentName.length() - SUFFIX.length());
    }


}

 最后不要忘记加上修改APN的权限：

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