安卓系统如何实现ssdp活接收器功能

Question

我试图实现一个函数来监听door 1900并捕获活动消息和设备ip，我试图使用我找到的一些libs，但我的应用程序在尝试启动应用程序时一直崩溃。

这是我的主要功能

     public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.splash_screen_layout);
   //----------SSDP para identificação da STB--------------------------------
        SSDPSocket sock;
        try {
            sock = new SSDPSocket();
            while (true) {
                DatagramPacket dp = sock.receive(); **//crashes here**
                String c = new String(dp.getData());
                System.out.println(c);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        //---------------------------------------------------------------------

lib的其余代码

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;
import java.net.SocketAddress;
public class SSDPSocket {
SocketAddress mSSDPMulticastGroup;
MulticastSocket mSSDPSocket;
public SSDPSocket() throws IOException {
    InetAddress localInAddress = InetAddress.getLocalHost(); **//crashes here first**
    System.out.println("Local address: " + localInAddress.getHostAddress());
    mSSDPMulticastGroup = new InetSocketAddress(SSDP.ADDRESS, SSDP.PORT);
    mSSDPSocket = new MulticastSocket(new InetSocketAddress(localInAddress,
            0));
    NetworkInterface netIf = NetworkInterface
            .getByInetAddress(localInAddress);
    mSSDPSocket.joinGroup(mSSDPMulticastGroup, netIf);
}
/* Used to receive SSDP packet */
public DatagramPacket receive() throws IOException {
    byte[] buf = new byte[1024];
    DatagramPacket dp = new DatagramPacket(buf, buf.length);
    mSSDPSocket.receive(dp);
    return dp;
}
public void close() {
    if (mSSDPSocket != null) {
        mSSDPSocket.close();
    }
}
}

public class SSDP {
/* New line definition */
public static final String NEWLINE = "rn";
public static final String ADDRESS = "239.255.255.250";
public static final int PORT = 1900;
/* Definitions of start line */
public static final String SL_NOTIFY = "NOTIFY * HTTP/1.1";
public static final String SL_MSEARCH = "M-SEARCH * HTTP/1.1";
public static final String SL_OK = "HTTP/1.1 200 OK";
/* Definitions of search targets */
public static final String ST_RootDevice = "ST:rootdevice";
public static final String ST_ContentDirectory = "ST:urn:schemas-upnp- org:service:ContentDirectory:1";
/* Definitions of notification sub type */
public static final String NTS_ALIVE = "NTS:ssdp:alive";
public static final String NTS_BYE = "NTS:ssdp:byebye";
public static final String NTS_UPDATE = "NTS:ssdp:update";
}


public class SSDPSearchMsg {
static final String HOST = "Host:" + SSDP.ADDRESS + ":" + SSDP.PORT;
static final String MAN = "Man:ssdp:discover";
int mMX = 3;    /* seconds to delay response */
String mST;     /* Search target */
public SSDPSearchMsg(String ST) {
    mST = ST;
}
public int getmMX() {
    return mMX;
}
public void setmMX(int mMX) {
    this.mMX = mMX;
}
public String getmST() {
    return mST;
}
public void setmST(String mST) {
    this.mST = mST;
}
@Override
public String toString() {
    StringBuilder content = new StringBuilder();
    content.append(SSDP.SL_MSEARCH).append(NEWLINE);
    content.append(HOST).append(NEWLINE);
    content.append(MAN).append(NEWLINE);
    content.append(mST).append(NEWLINE);
    content.append("MX:" + mMX).append(NEWLINE);
    content.append(NEWLINE);
    return content.toString();
}
}

Answer 1

似乎没有什么问题。

您是否在Mainifest中添加了多播权限？

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

Answer 2

Android不喜欢你在主线程中进行昂贵的操作，而且当你这样做时会抛出异常。试着用你创建的新线程执行该代码。那么它应该会起作用。