Android 的广播实现（Java）；
Android的广播分为两类：
第一类：动态广播需要实现BroadcastReceiver接口；进行注册。
实例：

class  guangbos extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            ConnectivityManager connectivityManager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo=connectivityManager.getActiveNetworkInfo();
            if (networkInfo!=null&&networkInfo.isAvailable()){
            }else{
                Toast.makeText(context,"无网络",Toast.LENGTH_SHORT).show();
            }
        }
    }

上面代码就是继承了BroadcastReceiver，需要在这里面添加IntentFilter添加拦截器，系统发出了什么广播，可以拦截到。全部代码如下：

public class MainActivity extends AppCompatActivity {

    private IntentFilter intentFilter;
    public guangbos mguangbos;
    private static final String TAG="TAG";
    private  boolean mCharge;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        intentFilter=new IntentFilter();
//        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");//connectivity_change
        intentFilter=new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        mguangbos=new guangbos();
        registerReceiver(mguangbos,intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mguangbos);
    }

    class  guangbos extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            ConnectivityManager connectivityManager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo=connectivityManager.getActiveNetworkInfo();
            if (networkInfo!=null&&networkInfo.isAvailable()){
            }else{
                Toast.makeText(context,"无网络",Toast.LENGTH_SHORT).show();
            }
        }
    }
}

第二种是静态注册，也就是在Androidmanfest.xml中直接注册，
需要的材料：
1.一个实现了BroadcastReceiver的类
2.在Androidmanfest添加如下代码

<receiver android:name=".ico_Test"//测试类
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED"></action>
            </intent-filter>
        </receiver>