can't instantiate class com.example.xxx.xx.MainActivity$MyReceiver不能初始化内部类

qiang_xi 2015-09-06 02:53:57
问题困扰我很久了,从国内国外网站均没有找到有效的解决办法,不知道大神们都怎么解决的,特来问一下,希望不吝赐教.
先说一下我要实现的功能:就是获取从bmob的服务器推送过来的消息,用BroadcastReceiver接收,接收到之后再发送一个广播给主界面的broadcastReceiver接收,获取到推送过来的数据之后显示到textView上.就这么简单,但是运行的时候老是报不能初始化类的异常,从各种渠道查找解决办法也没找到,不知道该怎么解决,请这里的大神给个有效的建议或者说,有更好的方式实现这个功能,下面是我的代码:


package com.example.administrator.bmob;



import android.app.Notification;

import android.app.NotificationManager;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.os.Bundle;

import android.util.Log;



import cn.bmob.push.PushConstants;



public class Receiver extends BroadcastReceiver {

    private NotificationManager manager;

    private String STATIC_NORMAL_ACTION = "com.example.administrator.bmob.TEST";



    @Override

    public void onReceive(Context context, Intent intent) {

        if (intent.getAction().equals(PushConstants.ACTION_MESSAGE)) {

            Log.d("bmob", "客户端收到推送内容：" + intent.getStringExtra(PushConstants.EXTRA_PUSH_MESSAGE_STRING));

            String msg = intent.getStringExtra(PushConstants.EXTRA_PUSH_MESSAGE_STRING);



            manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

            Notification.Builder builder = new Notification.Builder(context);

            builder.setContentText(msg)

                    .setDefaults(Notification.DEFAULT_LIGHTS | Notification.DEFAULT_SOUND)

                    .setTicker("懒人账本提醒...")

                    .setAutoCancel(true)

                    .setSmallIcon(R.mipmap.ic_launcher);

            Notification notification = builder.build();

            manager.notify(1, notification);

            Intent data = new Intent(STATIC_NORMAL_ACTION);

            Bundle bundle = new Bundle();

            bundle.putString("data", msg);

            data.putExtras(bundle);

            context.sendOrderedBroadcast(data, null);

        }

    }

}

主界面代码:
package com.example.administrator.bmob;



import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.widget.TextView;



import cn.bmob.push.BmobPush;

import cn.bmob.v3.Bmob;

import cn.bmob.v3.BmobInstallation;



public class MainActivity extends AppCompatActivity {

    private TextView textView;

    private String STATIC_NORMAL_ACTION = "com.example.administrator.bmob.TEST";

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);

        // 初始化BmobSDK

        Bmob.initialize(this, "336be8699869f10b984f71c0c3cdb91a");

        // 使用推送服务时的初始化操作

        BmobInstallation.getCurrentInstallation(this).save();

        // 启动推送服务

        BmobPush.startWork(this, "336be8699869f10b984f71c0c3cdb91a");



       /* IntentFilter filter = new IntentFilter(STATIC_NORMAL_ACTION);

        MyReceiver receiver = new MyReceiver();

        registerReceiver(receiver, filter);*/

    }

    public class MyReceiver extends BroadcastReceiver {

        @Override

        public void onReceive(Context context, Intent intent) {

            if (intent.getAction().equals(STATIC_NORMAL_ACTION)) {

                Bundle bundle = getResultExtras(true);

                String data = bundle.getString("data");

                textView.setText(data);

            }

        }

    }

}

这是报出来的异常:
 Caused by: java.lang.InstantiationException: can't instantiate class com.example.administrator.bmob.MainActivity$MyReceiver; no empty constructor

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qiang_xi 2015-09-06
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这个问题已经自己解决了,这里要采用动态注册广播接收者,并且要把注册代码放到activity的onStart()方法里,这样就能接收到了下面是代码: 
package com.example.administrator.bmob;

import android.app.Notification;
import android.app.NotificationManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;

import cn.bmob.push.PushConstants;

public class Receiver extends BroadcastReceiver {
    private NotificationManager manager;
    private String STATIC_NORMAL_ACTION = "com.example.administrator.bmob.TEST";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(PushConstants.ACTION_MESSAGE)) {
            Log.e("bmob", "客户端收到推送内容：" + intent.getStringExtra(PushConstants.EXTRA_PUSH_MESSAGE_STRING));
            String msg = intent.getStringExtra(PushConstants.EXTRA_PUSH_MESSAGE_STRING);

            manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            Notification.Builder builder = new Notification.Builder(context);
            builder.setContentText(msg)
                    .setDefaults(Notification.DEFAULT_LIGHTS | Notification.DEFAULT_SOUND)
                    .setTicker("懒人账本提醒...")
                    .setAutoCancel(true)
                    .setSmallIcon(R.mipmap.ic_launcher);
            Notification notification = builder.build();
            manager.notify(1, notification);

            Intent data = new Intent(STATIC_NORMAL_ACTION);
            Bundle bundle = new Bundle();
            bundle.putString("data", msg);
            data.putExtras(bundle);
            context.sendOrderedBroadcast(data, null);
            Log.e("data=",data.toString());
            Log.e("tag", "3");
        }
    }
}
主界面代码: 
package com.example.administrator.bmob;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

import cn.bmob.push.BmobPush;
import cn.bmob.v3.Bmob;
import cn.bmob.v3.BmobInstallation;

public class MainActivity extends AppCompatActivity {
    private TextView textView;
    private String STATIC_NORMAL_ACTION = "com.example.administrator.bmob.TEST";
    private BroadcastReceiver receiver;

    /**
     * 动态注册时,broadcastReceiver最好注册在onStart()方法中,这样只要程序不被关闭,都能收到广播
     * 最好不要注册在onCreate(Bundle savedInstanceState)方法里,因为在这个方法里注册后,立刻就失效了
     */
    @Override
    protected void onStart() {
        super.onStart();
        IntentFilter filter = new IntentFilter(STATIC_NORMAL_ACTION);
        registerReceiver(receiver, filter);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);
        // 初始化BmobSDK
        Bmob.initialize(this, "336be8699869f10b984f71c0c3cdb91a");
        // 使用推送服务时的初始化操作
        BmobInstallation.getCurrentInstallation(this).save();
        // 启动推送服务
        BmobPush.startWork(this, "336be8699869f10b984f71c0c3cdb91a");

        receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                if (intent.getAction().equals(STATIC_NORMAL_ACTION)) {
                    Bundle bundle = intent.getExtras();
                    String data = bundle.getString("data");
                    Toast.makeText(context,data,Toast.LENGTH_SHORT).show();
                    textView.setText(data);
                    Log.e("tag", "1");
                }
            }
        };
    }
}
qiang_xi 2015-09-06
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再补充一句,我的两个broadcastReceiver都采用静态方式注册好了
Android广播错误.MainActivity$MyReceiver; no empty constructor
http://blog.csdn.net/chdjj/article/details/19496567 19 09:11:14.650: E/AndroidRuntime(1771): java.lang.RuntimeException: Unable to instantiate receiver com.example.brocastdemo.MainActivity$MyRe
Android 内部类广播错误.MainActivity$MyReceiver; no empty constructor
广播的定义，如果是内部类，必须为静态类 http://blog.csdn.net/chdjj/article/details/19496567 下面总结一下作为内部类的广播接收者在注册的时候需要注意的地方： 1.清单文件注册广播接收者时，广播接收者的名字格式需要注意。因为是内部类，所以需要在内部类所在的类与内部类之间加上$符号: [html] view
Unable to instantiate receiver
java.lang.RuntimeException: Unable to instantiate receiver com.example.mylibrary02.activity.UpdateAppActivity$MyReceiver: java.lang.InstantiationException: can't instantiate class com.example.mylibrar...
Caused by: java.lang.InstantiationException: can't instantiate class报错记录
E/AndroidRuntime(15377): Caused by: java.lang.InstantiationException: can't instantiate class com.*.*.FriendsActivity; no empty constructor 在用fragment做跳转的时候出现的错误记录解决办法：是因为该Fragment没有使用空参的构造函数，补上-- p
java.lang.InstantiationException: can't instantiate class
java.lang.InstantiationException: can't instantiate class  因为类的属性写成 abstract
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