import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;
import org.osmdroid.config.Configuration;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.ItemizedIconOverlay;
import org.osmdroid.views.overlay.OverlayItem;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
public class MainActivity extends Activity {
MapView mv;
ItemizedIconOverlay<OverlayItem> items;
ItemizedIconOverlay.OnItemGestureListener<OverlayItem> markerGestureListener;
protected void OnCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
items = new ItemizedIconOverlay<OverlayItem>(this, new ArrayList<OverlayItem>(), null);
Configuration.getInstance().load(this, PreferenceManager.getDefaultSharedPreferences(this));
LocationManager mgr = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
mgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, (LocationListener) this);
mv = (MapView) findViewById(R.id.mvID);
mv.setBuiltInZoomControls(true);
mv.getController().setZoom(12);
mv.getController().setCenter(new GeoPoint(50.907703,-1.401472));
}
public void onLocationChanged(Location newLoc) {
Toast.makeText
(this, "Location=" +
newLoc.getLatitude() + " " +
newLoc.getLongitude(), Toast.LENGTH_LONG).show();
mv.getController().setCenter(new GeoPoint(newLoc.getLatitude(), newLoc.getLongitude()));
}
public void onProviderDisabled(String provider)
{
Toast.makeText(this, "Provider " + provider +
" disabled", Toast.LENGTH_LONG).show();
}
public void onProviderEnabled(String provider)
{
Toast.makeText(this, "Provider " + provider +
" enabled", Toast.LENGTH_LONG).show();
}
public void onStatusChanged(String provider,int status,Bundle extras)
{
Toast.makeText(this, "Status changed: " + status,
Toast.LENGTH_LONG).show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.newResID){
Intent intent = new Intent (this, AddPlace.class);
startActivityForResult(intent, 0);
return true;
}
if (item.getItemId() == R.id.saveResID){
try {
PrintWriter pw =
new PrintWriter(new FileWriter(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data.csv", true));
for(int i=0; i<items.size(); i++){
OverlayItem itm = items.getItem(i);
pw.println(itm.getTitle()+","+itm.getSnippet()+","+itm.getPoint().getLatitude()+","+itm.getPoint().getLongitude());
}
pw.close();
}
catch (IOException e){
new AlertDialog.Builder(this).setMessage("ERROR Loading:" + e).
setPositiveButton("OK", null).show();
}
}
if (item.getItemId() == R.id.setPrefID){
Intent intent = new Intent (this, PreferencesActivity.class);
startActivityForResult(intent, 1);
return true;
}
if (item.getItemId() == R.id.setPrefID){
try
{
BufferedReader reader = new BufferedReader(new FileReader(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data.csv"));
String line;
while((line = reader.readLine()) != null)
{
String[] components = line.split(",");
if(components.length==4)
{
Double lat = Double.valueOf(components[2]).doubleValue();
Double lon = Double.valueOf(components[3]).doubleValue();
OverlayItem itm = new OverlayItem(components[0], components[1], new GeoPoint(lat, lon));
items.addItem(itm);
}
}
}
catch(IOException e)
{
new AlertDialog.Builder(this).setMessage("ERROR Loading:" + e).
setPositiveButton("OK", null).show();
}
return true;
}
return false;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 0){
if (resultCode == RESULT_OK){
Bundle extras = data.getExtras();
String name = data.getExtras().getString("com.example.a2colej34.place_name_input");
String address = data.getExtras().getString("com.example.a2colej34.place_type_input");
String cuisine = data.getExtras().getString("com.example.a2colej34.place_price_input");
double lat = mv.getMapCenter().getLatitude();
double lon = mv.getMapCenter().getLongitude();
items = new ItemizedIconOverlay<OverlayItem>(this, new ArrayList<OverlayItem>(),markerGestureListener);
OverlayItem newRestaurant = new OverlayItem(name+ " ", address+" "+cuisine+" ", new GeoPoint(lat,lon));
items.addItem(newRestaurant);
mv.getOverlays().add(items);
SharedPreferences customPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
boolean autosave = customPrefs.getBoolean("autosave", true);
if(autosave){
try {
PrintWriter pw =
new PrintWriter(new FileWriter(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data.csv", true));
for(int i=0; i<items.size(); i++){
OverlayItem itm = items.getItem(i);
pw.println(itm.getTitle()+","+itm.getSnippet()+","+itm.getPoint().getLatitude()+","+itm.getPoint().getLongitude());
}
pw.close();
}
catch (IOException e){
new AlertDialog.Builder(this).setMessage("ERROR Loading: " + e).
setPositiveButton("OK", null).show();
}
}
}
}
}
@Override
protected void onStart()
{
super.onStart();
try
{
BufferedReader reader = new BufferedReader(new FileReader(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data.csv"));
String line;
while((line = reader.readLine()) != null)
{
String[] components = line.split(",");
if(components.length==4)
{
Double lat = Double.valueOf(components[2]).doubleValue();
Double lon = Double.valueOf(components[3]).doubleValue();
OverlayItem itm = new OverlayItem(components[0], components[1], new GeoPoint(lat, lon));
items.addItem(itm);
}
}
}
catch(IOException e)
{
new AlertDialog.Builder(this).setMessage("ERROR Loading: " + e).
setPositiveButton("OK", null).show();
}
}
}
在android studio上运行模拟器，我收到以下错误；
加载java.io.filenotfoundexception时出错：/storage/sdcard/data.csv：打开失败：ENOENT
我的代码没有显示错误，所以我不确定为什么模拟器拒绝打开应用程序的选项。 我已经研究了代码，并且了解到这种情况下没有可用的目录，感谢您对stackoverflow还是陌生的，希望对我的问题有所帮助。
答案 0 :(得分：0)
BufferedReader reader = new BufferedReader(new FileReader(Environment.getExternalStorageDirectory().getAbsolutePath() + "/data.csv"));
在此行上，您尝试打开一个文件。该文件在您的模拟器上不存在，因此无法打开。 Android Studio没有显示任何错误，因为在编译期间没有问题，因为如果文件存在，应用程序将运行良好。