我们在做Android平台GB28181的时候,其中实时位置(MobilePosition)订阅和上报这块,涉及到实时经纬度的获取,特别是执法记录、车载系统的那个等场景,几乎就是标配。
今天主要是分享一段实时获取位置的代码:
代码语言:javascript复制/*
* CameraPublishActivity.java
* CameraPublishActivity
*
* Github: https://github.com/daniulive/SmarterStreaming
*/
private void getLocation(Context context) {
try {
if ( context == null )
return;
//1.获取位置管理器
if ( mLocationManager == null )
mLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
if (mLocationManager == null)
return;
//2.获取位置提供器,GPS或是NetWork
List<String> providers = mLocationManager.getProviders(true);
if ( providers != null ) {
if (providers.contains(LocationManager.NETWORK_PROVIDER)){
//如果是网络定位
mLocationProvider = LocationManager.NETWORK_PROVIDER;
}else if (providers.contains(LocationManager.GPS_PROVIDER)){
//如果是GPS定位
mLocationProvider = LocationManager.GPS_PROVIDER;
}else {
Toast.makeText(this, "没有可用的位置提供器", Toast.LENGTH_SHORT).show();
return;
}
}
if (mLocationProvider == null )
return;
mLocationManager.removeUpdates(mLocationListener);
mLocationManager.requestLocationUpdates(mLocationProvider, 500, 1.0f, mLocationListener);
//3.获取上次的位置,一般第一次运行,此值为null
Location location = mLocationManager.getLastKnownLocation(mLocationProvider);
if (location!=null) {
updateLocation(location);
}
}catch (Exception e) {
Log.e(TAG, "getLocation exception:" e.getMessage());
e.printStackTrace();
}
}
private void updateLocation(Location location){
//long utc_time = location.getTime();
//long local_time = utc_time TimeZone.getDefault().getOffset(utc_time);
//Date date = new Date(location.getTime());
Date date = new Date(System.currentTimeMillis());
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
String time_str = dateFormat.format(date);
// String address = "纬度:" location.getLatitude() " 经度:" location.getLongitude() " 时间:" time_str;
//Log.i(TAG, "位置信息: " address);
mLocationTime = time_str;
mLatitude = String.valueOf(location.getLatitude());
mLongitude = String.valueOf(location.getLongitude());
}
LocationListener mLocationListener = new LocationListener() {
@Override
public void onStatusChanged(String provider, int {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
// 如果位置发生变化,重新显示
@Override
public void onLocationChanged(Location location)
国标平台开启位置订阅后,Android平台GB28181接入端根据平台侧发过来的时间间隔要求,周期性的更新实时位置信息,相关流程如下:
其中,SUBSCRIBE请求XML描述如下,除了常规信息外,还提供了Interval,供接入端使用。
代码语言:javascript复制<?xml versinotallow="1.0" encoding="GB2312"
<Query>
<CmdType>MobilePosition</CmdType>
<SN>55674</SN>
<DeviceID>31011500991320000099</DeviceID>
<Interval>5</Interval>
</Query>
Android国标接入端上报NOTIFY请求示例,请求体XML示例如下:
代码语言:javascript复制<?xml versinotallow="1.0" encoding="GB2312"
<Notify>
<CmdType>MobilePosition</CmdType>
<SN>71339</SN>
<TargetID>31011500991320000099</TargetID>
<Time>2022-03-19T12:22:20</Time>
<Longitude>143.507222</Longitude>
<Latitude>33.99011311</Latitude>
</Notify>
当底层有DevicePosition处理诉求时,可参考如下实现:
代码语言:javascript复制@Override
public void ntsOnDevicePositionRequest(String deviceId, int {
handler_.postDelayed(new Runnable() {
@Override
public void run() {
getLocation(context_);
Log.v(TAG, "ntsOnDevicePositionRequest, deviceId:" this.device_id_ ", Longitude:" mLongitude
", Latitude:" mLatitude ", Time:" mLocationTime);
if (mLongitude != null && mLatitude != null) {
com.gb.ntsignalling.DevicePosition device_pos = new com.gb.ntsignalling.DevicePosition();
device_pos.setTime(mLocationTime);
device_pos.setLongitude(mLongitude);
device_pos.setLatitude(mLatitude);
if (gb28181_agent_ != null ) {
gb28181_agent_.updateDevicePosition(device_id_, device_pos);
}
}
}
private String device_id_;
private int interval_;
public Runnable set(String device_id, int {
this.device_id_ = device_id;
this.interval_ = interval;
return this;
}
}.set(deviceId, interval),0);
}
以下是大概的流程,感兴趣的开发者,可以酌情参考。