我想在两个手机之间使用WiFi P2P连接发送数据。这与低于8(OREO(的Android版本非常有效,但是当我尝试发送某些内容时,该程序在Android 8上停止。我多次检查了代码,但找不到问题。
package com.example.wificonnectiontry2;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.location.LocationManager;
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.Build;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
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 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.List;
public class MainActivity extends AppCompatActivity {
private Button btnOnOff, btnDiscover, btnSend;
private ListView listView;
private TextView read_msg_box, connectionStatus;
private EditText writeMsg;
private WifiManager wifiManager;
private WifiP2pManager mManager;
private WifiP2pManager.Channel mChannel;
private BroadcastReceiver mReceiver;
private IntentFilter mIntentFilter;
private List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
private String[] deviceNameArray;
private WifiP2pDevice[] deviceArray;
private static final int MESSAGE_READ = 1;
ServerClass serverClass;
ClientClass clientClass;
SendReceive sendReceive;
private boolean gpsGoOn = false;
private boolean connected = false;
@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);
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("Wifi On");
}else{
wifiManager.setWifiEnabled(true);
btnOnOff.setText("Wifi Off");
}
}
});
btnDiscover.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
discoverPeers();
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
final WifiP2pDevice device = deviceArray[position];
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) {
if(connected) {
String msg = writeMsg.getText().toString();
sendReceive.write(msg.getBytes());
}
}
});
}
private void discoverPeers(){
mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
@Override
public void onSuccess() {
connectionStatus.setText("Discovery Started");
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
LocationManager L = (LocationManager) getSystemService(LOCATION_SERVICE);
if (!L.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Toast.makeText(getApplicationContext(), "Please activate GPS", Toast.LENGTH_LONG).show();
gpsGoOn = true;
startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
}
}
}
@Override
public void onFailure(int reason) {
connectionStatus.setText("Discovery Starting Failed");
}
});
}
private void initialWork() {
btnOnOff = (Button) findViewById(R.id.onOff);
btnDiscover = (Button) findViewById(R.id.discover);
btnSend = (Button) findViewById(R.id.sendButton);
listView = (ListView) findViewById(R.id.peerListView);
read_msg_box = (TextView) findViewById(R.id.readMsg);
connectionStatus = (TextView) findViewById(R.id.connectionStatus);
writeMsg = (EditText) findViewById(R.id.writeMsg);
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);
mIntentFilter = new IntentFilter();
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_DISCOVERY_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);
}
WifiP2pManager.PeerListListener peerListListener = new WifiP2pManager.PeerListListener() {
@Override
public void onPeersAvailable(WifiP2pDeviceList peerList) {
if(!peerList.getDeviceList().equals(peers)){
peers.clear();
peers.addAll(peerList.getDeviceList());
deviceNameArray = new String[peerList.getDeviceList().size()];
deviceArray = new WifiP2pDevice[peerList.getDeviceList().size()];
int index = 0;
for(WifiP2pDevice device : peerList.getDeviceList()){
deviceNameArray[index] = device.deviceName;
deviceArray[index] = device;
index++;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplicationContext(), 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();
return;
}
}
};
WifiP2pManager.ConnectionInfoListener connectionInfoListener = new WifiP2pManager.ConnectionInfoListener() {
@Override
public void onConnectionInfoAvailable(WifiP2pInfo info) {
final InetAddress groupOwner = info.groupOwnerAddress;
if(info.groupFormed && info.isGroupOwner){
connectionStatus.setText("Host");
serverClass = new ServerClass();
serverClass.start();
}else{
connectionStatus.setText("Client");
clientClass = new ClientClass(groupOwner);
clientClass.start();
}
connected = true;
}
};
public void setConnectionText(String text){
connectionStatus.setText(text);
}
@Override
protected void onResume() {
super.onResume();
registerReceiver(mReceiver, mIntentFilter);
if(gpsGoOn){
discoverPeers();
}
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(mReceiver);
}
private class SendReceive extends Thread{
private Socket socket;
private InputStream inputStream;
private OutputStream outputStream;
public 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();
}
}
}
public void write(byte[] bytes){
try {
outputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
}
public class ServerClass extends Thread{
private Socket socket;
private 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();
}
}
}
}
那是我发送某些内容后收到的错误消息。
---------崩溃的开始
2019-07-29 20:15:22.468 8068-8068/com.example.wificonnectiontry2 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.wificonnectiontry2, PID: 8068
android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1448)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:108)
at java.net.SocketOutputStream.write(SocketOutputStream.java:141)
at com.example.wificonnectiontry2.MainActivity$SendReceive.write(MainActivity.java:320)
at com.example.wificonnectiontry2.MainActivity$5.onClick(MainActivity.java:137)
at android.view.View.performClick(View.java:6897)
at android.widget.TextView.performClick(TextView.java:12693)
at android.view.View$PerformClick.run(View.java:26101)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6944)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
NetworkOnMainThreadException
是在定位蜂窝或更高版本时提高的,然后尝试从主UI线程执行网络操作。在较旧的Android版本中,允许(但不建议(。现代Android版本不再是这种情况。您必须将网络代码转移到单独的线程或背景任务中。