我试图制作一个可以在2个Android手机之间使用Wifip2p连接传输消息的应用程序。虽然我可以连接两个手机，但无法将消息从一个手机发送到另一个手机。发送消息时，应用程序关闭。我知道问题出在哪里，但我不知道如何解决？代码如下：
这是我的activity_main.xml文件
/**
* Plugin implementation of the event_entity_field field type.
* @FieldType(
* id = "event_entity_field",
* label = @Translation("Event Config"),
* description = @Translation("Stores an event config."),
* default_widget = "event_config_default",
* default_formatter = "event_config_default",
* category = @Translation("Other"),
* )
*/
class EventConfigField extends FieldItemBase implements
FieldItemInterface {
public static function schema(FieldStorageDefinitionInterface
$field_definition) {
return [
'columns' => [
'id' => [
'type' => 'serial',
'not null' => TRUE,
],
'event_name' => [
'type' => 'varchar',
'length' => 256,
],
'venue' => [
'type' => 'varchar',
'length' => 256,
],
],
'foreign keys' => [
'event_name' => [
'table' => 'event',
'columns' => ['event_name' => 'event_name'],
],
],
];
}
public static function
propertyDefinitions(FieldStorageDefinitionInterface
$field_definition) {
$properties['event_name'] = DataDefinition::create('string')
->setLabel(new TranslatableMarkup('event_name'));
$properties['venue'] = DataDefinition::create('string')
->setLabel(new TranslatableMarkup('venue'));
}
}
这是AndroidManifest.xml文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/onOff"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="28dp"
android:layout_marginTop="55dp"
android:text="Wifi On" />
<Button
android:id="@+id/discover"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/onOff"
android:layout_alignBottom="@+id/onOff"
android:layout_centerHorizontal="true"
android:text="discover" />
<ListView
android:id="@+id/peerListView"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_alignParentStart="true"
android:layout_below="@+id/onOff"
android:layout_marginTop="25dp"
android:background="@android:color/holo_orange_light" />
<TextView
android:id="@+id/readMsg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentStart="true"
android:layout_below="@+id/peerListView"
android:layout_marginTop="31dp"
android:text="Message"
android:textAlignment="center"
android:textSize="20sp"
android:textStyle="italic" />
<EditText
android:id="@+id/writeMsg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:ems="10"
android:inputType="textPersonName"
android:layout_toStartOf="@+id/sendButton" />
<Button
android:id="@+id/sendButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:text="Send" />
<TextView
android:id="@+id/connectionStatus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="15dp"
android:text="Connection Status"
android:textAlignment="center"
android:textColor="@android:color/holo_blue_dark"
android:textSize="18sp"
android:textStyle="italic" />
</RelativeLayout>
这是mainactivity.java文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.wifip2p.iotwifi">
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
<uses-feature android:name="android.hardware.wifi.direct" android:required="true" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
这是我的WifiDirectBroadcastReceiver.java文件
package com.wifip2p.iotwifi;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.graphics.Color;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pConfig;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.google.gson.Gson;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
public class MainActivity extends AppCompatActivity {
Button btnOnOff,btnDiscover,btnSend;
ListView listView;
TextView read_msg_box,connectionStatus;
EditText writeMsg;
WifiManager wifiManager;
WifiP2pManager mManager;
WifiP2pManager.Channel mChannel;
BroadcastReceiver mReceiver;
String[] deviceNameArray;
WifiP2pDevice[] deviceArray;
private final IntentFilter mIntentFilter = new IntentFilter();
private Collection<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
static final int MESSAGE_READ=1;
ServerClass serverClass;
ClientClass clientClass;
SendReceive sendReceive;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initialWork();
exqListener();
}
Handler handler = new Handler(new Handler.Callback() {
@Override
public boolean handleMessage(Message msg) {
switch (msg.what){
case MESSAGE_READ:
byte[] readBuff = (byte[]) msg.obj;
String tempMsg = new String(readBuff,0,msg.arg1);
if(tempMsg != null) {
read_msg_box.setText(tempMsg);
}
break;
}
return true;
}
});
private void exqListener() {
btnOnOff.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(wifiManager.isWifiEnabled()){
wifiManager.setWifiEnabled(false);
btnOnOff.setText("Off");
btnOnOff.setBackgroundColor(Color.GREEN);
} else {
wifiManager.setWifiEnabled(true);
btnOnOff.setText("ON");
btnOnOff.setBackgroundColor(Color.RED);
}
}
});
btnDiscover.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
@Override
public void onSuccess() {
connectionStatus.setText("Discovery Started");
}
@Override
public void onFailure(int reason) {
connectionStatus.setText("Discovery Failed");
}
});
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
final WifiP2pDevice device = deviceArray[i];
WifiP2pConfig config = new WifiP2pConfig();
config.deviceAddress = device.deviceAddress;
mManager.connect(mChannel, config, new WifiP2pManager.ActionListener() {
@Override
public void onSuccess() {
Toast.makeText(getApplicationContext(),"Connected to "+device.deviceName,Toast.LENGTH_SHORT).show();
}
@Override
public void onFailure(int reason) {
Toast.makeText(getApplicationContext(),"Not Connected",Toast.LENGTH_SHORT).show();
}
});
}
});
btnSend.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String msg = writeMsg.getText().toString();
if(sendReceive != null) {
sendReceive.write(msg.getBytes());
} else {
Toast.makeText(getApplicationContext(),"No SR Obj found",Toast.LENGTH_SHORT).show();
}
}
});
}
WifiP2pManager.PeerListListener peerListListener = new WifiP2pManager.PeerListListener() {
@Override
public void onPeersAvailable(WifiP2pDeviceList peerList) {
Collection<WifiP2pDevice> refreshedPeers = peerList.getDeviceList();
if(!refreshedPeers.equals(peers)){
peers.clear();
peers.addAll(refreshedPeers);
deviceNameArray = new String[refreshedPeers.size()];
deviceArray = new WifiP2pDevice[refreshedPeers.size()];
int index = 0;
// maybe we can get more information here
for(WifiP2pDevice device : refreshedPeers){
deviceNameArray[index] = device.deviceName;
deviceArray[index] = device;
index++;
}
Log.d("this is my array", "arr: " + Arrays.toString(deviceNameArray));
ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1, deviceNameArray);
listView.setAdapter(adapter);
}
if(peers.size() == 0){
Toast.makeText(getApplicationContext(),"No Device Found",Toast.LENGTH_SHORT).show();
Log.d("WIFIDIRECT", "No devices found");
return;
}
}
};
WifiP2pManager.ConnectionInfoListener connectionInfoListener= new WifiP2pManager.ConnectionInfoListener() {
@Override
public void onConnectionInfoAvailable(WifiP2pInfo wifiP2pInfo) {
final InetAddress groupOwnerAddress = wifiP2pInfo.groupOwnerAddress;
if(wifiP2pInfo.groupFormed && wifiP2pInfo.isGroupOwner){
connectionStatus.setText("Host");
serverClass = new ServerClass();
serverClass.start();
} else if (wifiP2pInfo.groupFormed) {
connectionStatus.setText("Client");
clientClass = new ClientClass(groupOwnerAddress);
clientClass.start();
}
}
};
public class ServerClass extends Thread{
Socket socket;
ServerSocket serverSocket;
@Override
public void run() {
try{
serverSocket = new ServerSocket(8888);
socket = serverSocket.accept();
sendReceive = new SendReceive(socket);
sendReceive.start();
}catch (IOException e){
e.printStackTrace();
}
}
}
public class ClientClass extends Thread{
Socket socket;
String hostAdd;
public ClientClass(InetAddress hostAddress){
hostAdd = hostAddress.getHostAddress();
socket = new Socket();
}
@Override
public void run() {
try{
socket.connect(new InetSocketAddress(hostAdd,8888),500);
sendReceive = new SendReceive(socket);
sendReceive.start();
} catch (IOException e){
e.printStackTrace();
}
}
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(mReceiver);
}
@Override
protected void onResume() {
super.onResume();
registerReceiver(mReceiver,mIntentFilter);
}
private class SendReceive extends Thread{
private Socket socket;
private InputStream inputStream ;
private OutputStream outputStream;
private SendReceive(Socket skt){
socket = skt;
try{
inputStream = socket.getInputStream();
outputStream = socket.getOutputStream();
}catch(IOException e){
e.printStackTrace();
}
}
@Override
public void run() {
byte[] buffer = new byte[1024];
int bytes;
while(socket != null){
try {
bytes= inputStream.read(buffer);
if(bytes>0){
handler.obtainMessage(MESSAGE_READ,bytes,-1,buffer).sendToTarget();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void write (byte[] bytes){
if(bytes != null) {
try {
outputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void initialWork() {
btnOnOff = findViewById(R.id.onOff);
btnDiscover = findViewById(R.id.discover);
btnSend = findViewById(R.id.sendButton);
listView = findViewById(R.id.peerListView);
read_msg_box = findViewById(R.id.readMsg);
connectionStatus = findViewById(R.id.connectionStatus);
writeMsg = findViewById(R.id.writeMsg);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mManager.initialize(this,getMainLooper(),null);
mReceiver = new WifiDirectBroadcastReceiver(mManager,mChannel,this);
}
}
错误在于mainactivity.java文件中
package com.wifip2p.iotwifi;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.NetworkInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.util.Log;
import android.widget.Toast;
public class WifiDirectBroadcastReceiver extends BroadcastReceiver {
private WifiP2pManager mManager;
private WifiP2pManager.Channel mChannel;
private MainActivity mActivity;
public WifiDirectBroadcastReceiver(WifiP2pManager mManager,WifiP2pManager.Channel mChannel,MainActivity mActivity){
this.mManager = mManager;
this.mChannel = mChannel;
this.mActivity = mActivity;
}
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
// Determine if Wifi P2P mode is enabled or not, alert
// the Activity.
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
Toast.makeText(context,"WIFI is ON",Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(context,"WIFI is OFF",Toast.LENGTH_SHORT).show();
}
} else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
if(mManager != null){
mManager.requestPeers(mChannel,mActivity.peerListListener);
}
} else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
if(mManager != null){
return;
}
NetworkInfo networkInfo = intent.getParcelableExtra(WifiP2pManager.EXTRA_NETWORK_INFO);
if(networkInfo.isConnected()){
mManager.requestConnectionInfo(mChannel,mActivity.connectionInfoListener);
} else {
mActivity.connectionStatus.setText("Device Disconnected");
}
} else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
}
}
}
if(sendReceive != null) {
sendReceive.write(msg.getBytes());
} else {
Toast.makeText(getApplicationContext(),"No SR Obj found",Toast.LENGTH_SHORT).show();
}
未实例化。