在看Android代碼的時候發現有使用LocalSocket，比java本身的socket效率要高，好像沒有經過協議棧，是android自己實現的類似共享內存一樣的東東，在傳輸大量數據的時候就需要用到，比如視頻數據,在RIL電話那部分也用到。剛好項目用到視頻傳輸，我試用了一把，果然不錯！
public static final String SOCKET_ADDRESS = "socket_cmmb_sim_command";//這個名字要記好，在接受端要用到，可以理解為共享內存的設備文件名。
.....
try {
LocalServerSocket server = new LocalServerSocket(SOCKET_ADDRESS);
while (true) {
//Log.i(TAG, "begin accept");
LocalSocket receiver = server.accept();
if (receiver != null) {
InputStream input = receiver.getInputStream();
byte[] bytes = new byte[4];
int size = input.read(bytes, 0, 4);
if(size!=4) Log.i(TAG, "received command len:" + String.valueOf(size));
int cmd_len = ((bytes[0] & 0xFF) << 24)|((bytes[1] & 0xFF) << 16)
|((bytes[2] & 0xFF) << 8)|(bytes[3] & 0xFF);
Log.i(TAG, "received cmd_len:"+String.valueOf(cmd_len));
if(cmd_len>0){
byte[] ArrayOfByte = new byte[cmd_len];
size = input.read(ArrayOfByte, 0, cmd_len);
Log.i(TAG, "received data len:" + String.valueOf(size));
Parcel parcel = Parcel.obtain();
parcel.unmarshall(ArrayOfByte, 0, ArrayOfByte.length);
parcel.setDataPosition(0);
processRequest(receiver,parcel);
}
}
}
} catch (IOException e) {
Log.e(getClass().getName(), e.getMessage());
}
private void sendResult(LocalSocket paramLocalSocket, Parcel paramParcel) throws IOException{
byte[] arrayOfByte1 = new byte[4];
byte[] arrayOfByte2 = paramParcel.marshall();
Log.i(TAG, "enter sendResult!");
arrayOfByte1[0] = 0;
arrayOfByte1[1] = 0;
arrayOfByte1[2] = (byte)(arrayOfByte2.length >> 8 & 0xFF);
arrayOfByte1[3] = (byte)(arrayOfByte2.length & 0xFF);
paramLocalSocket.getOutputStream().write(arrayOfByte1);
paramLocalSocket.getOutputStream().write(arrayOfByte2);
}
private void processRequest(LocalSocket paramLocalSocket, Parcel paramParcel)
{
int cmd = paramParcel.readInt();
//Log.i(TAG,"parcel:"+String.valueOf(cmd));
if(cmd>0&&cmd<CMMB_REQUEST_CMD_MAX){
//String info = "unknown";
Parcel parcel_info = Parcel.obtain();
TelephonyManager tm = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
switch (cmd)
{
case CMMB_REQUEST_GET_IMSI:{
Log.i(TAG, "received CMMB_REQUEST_GET_IMSI command!");
/*
* 唯一的用戶ID：
* 例如：IMSI(國際移動用戶識別碼) for a GSM phone.
* 需要權限：READ_PHONE_STATE
*/
String info = tm.getSubscriberId();//String
if(info!=null) Log.i(TAG, info);
parcel_info.writeInt(CMMB_REQUEST_GET_IMSI);
parcel_info.writeString(info);
}
break;
....
try {
sendResult(paramLocalSocket, parcel_info);
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e(getClass().getName(), e.getMessage());
e.printStackTrace();
}
}
以上是服務器端，下面是客戶端
#define SOCKET_NAME_CMMB_SIM_COMMAND "socket_cmmb_sim_command"
...
fd = socket_local_client(
SOCKET_NAME_CMMB_SIM_COMMAND,
ANDROID_SOCKET_NAMESPACE_ABSTRACT,
SOCK_STREAM );
//check open failed
if (fd < 0)
{
LOGE("Failed to open socket: %s\n\r'", SOCKET_NAME_CMMB_SIM_COMMAND);
goto error;
}
//get command data
p_request.writeInt32 (CMMB_REQUEST_GET_IMSI);
data = (char *)p_request.data();
datasize = (int)p_request.dataSize();
//get command length
dataLength[0] = dataLength[1] = 0;
dataLength[2] = (char)((datasize >> 8) & 0xff);
dataLength[3] = (char)(datasize & 0xff);
//write command getimsi length
if(SmsMbbmsSimSocketWrite(fd, dataLength, sizeof(dataLength)) != sizeof(dataLength))
{
LOGE("Failed to write cmmand %d 's length to socket: %s!!!!!\n'", CMMB_REQUEST_GET_IMSI, SOCKET_NAME_CMMB_SIM_COMMAND);
goto error;
}
//write command getimsi
if(SmsMbbmsSimSocketWrite(fd, data, datasize) != datasize)
{
LOGE("Failed to write cmmand %d to socket: %s!!!!\n'", CMMB_REQUEST_GET_IMSI, SOCKET_NAME_CMMB_SIM_COMMAND);
goto error;
}
//write end, start read response
//read head, include length of data, 4 byte
if(SmsMbbmsSimSocketRead(fd, response_data, 4) != 4)
{
LOGE("Failed to read response command %d 's length from socket: %s!!!!!\n'", CMMB_REQUEST_GET_IMSI, SOCKET_NAME_CMMB_SIM_COMMAND);
goto error;
}
//LOGD("response_data of length: %d, %d, %d, %d!!!\n", response_data[0], response_data[1], response_data[2], response_data[3]);
//calculate length
response_length = ((response_data[0] & 0xff) << 24)
| ((response_data[1] & 0xff) << 16)
| ((response_data[2] & 0xff) << 8)
| (response_data[3] & 0xff);
//LOGD("response_length = %d\n", response_length);
//check length
if(response_length == 0)
{
LOGE("response %d 's length from socket: %s is not right!!!!!\n'", CMMB_REQUEST_GET_IMSI, SOCKET_NAME_CMMB_SIM_COMMAND);
goto error;
}
...
這樣就是實現了客戶端和服務器之間的通信。
