Java 如何获得用户'；现在的城市是什么？

我想通过Android应用程序获取用户的当前位置。我一直看到错误信息，如果从手机的GPS获取位置出错，应该显示错误信息。你们能告诉我我的密码有什么问题吗

MainActivity.java:

package com.example.apple.project;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    private static final int MY_PERMISSIONS_REQUEST_LOCATION = 1;

    TextView textView;

    Button button;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);

        button = (Button) findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (ContextCompat.checkSelfPermission(MainActivity.this,
                        Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                            Manifest.permission.ACCESS_COARSE_LOCATION)) {
                        ActivityCompat.requestPermissions(MainActivity.this,
                                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);
                    } else {
                        ActivityCompat.requestPermissions(MainActivity.this,
                                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);
                    }
                } else {
                    LocationManager mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                    Location location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    try {
                        textView.setText(hereLocation(location.getLatitude(), location.getLongitude()));
                    } catch (Exception e) {
                        Toast.makeText(getApplicationContext(), "Not found!",
                                Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (ContextCompat.checkSelfPermission(MainActivity.this,
                            Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

                        LocationManager mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                        Location location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        try {
                            textView.setText(hereLocation(location.getLatitude(), location.getLongitude()));
                        } catch (Exception e) {
                            Toast.makeText(getApplicationContext(), "Not found!",
                                    Toast.LENGTH_SHORT).show();
                        }

                    }
                } else {
                    Toast.makeText(MainActivity.this, "No permission granted!", Toast.LENGTH_SHORT).show();
                }
                return;
            }
        }
    }

    public String hereLocation(double lat, double lng) {
        String cur_city_name = "";

        Geocoder gcd = new Geocoder(MainActivity.this,
                Locale.getDefault());
        List<Address> addresses;
        try {
            addresses = gcd.getFromLocation(lat, lng, 1);
            if (addresses.size() > 0)
                cur_city_name = addresses.get(0).getLocality();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Toast.makeText(this, "" + cur_city_name, Toast.LENGTH_SHORT).show();
        return cur_city_name;
    }


}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout        
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

package com.example.apple.project；
导入android.Manifest；
导入android.content.Context；
导入android.content.pm.PackageManager；
导入android.location.Address；
导入android.location.Geocoder；
导入android.location.location；
导入android.location.LocationManager；
导入android.os.Bundle；
导入android.support.v4.app.ActivityCompat；
导入android.support.v4.content.ContextCompat；
导入android.support.v7.app.AppActivity；
导入android.view.view；
导入android.widget.Button；
导入android.widget.TextView；
导入android.widget.Toast；
导入java.io.IOException；
导入java.util.List；
导入java.util.Locale；
公共类MainActivity扩展了AppCompatActivity{
私有静态final int MY_PERMISSIONS_REQUEST_LOCATION=1；
文本视图文本视图；
按钮；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
textView=（textView）findViewById（R.id.textView）；
按钮=（按钮）findViewById（R.id.button）；
setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
if（ContextCompat.checkSelfPermission）（MainActivity.this，
Manifest.permission.ACCESS\u\u位置）！=PackageManager.permission\u已授予）{
如果（ActivityCompat.shouldShowRequestPermissionRegulation）（MainActivity.this，
清单.权限.访问（位置）{
ActivityCompat.requestPermissions（MainActivity.this，
新字符串[]{Manifest.permission.ACCESS\u\u LOCATION}，MY\u PERMISSIONS\u REQUEST\u LOCATION）；
}否则{
ActivityCompat.requestPermissions（MainActivity.this，
新字符串[]{Manifest.permission.ACCESS\u\u LOCATION}，MY\u PERMISSIONS\u REQUEST\u LOCATION）；
}
}否则{
LocationManager MLLocationManager=（LocationManager）getSystemService（Context.LOCATION\u服务）；
Location Location=mlLocationManager.getLastKnownLocation（LocationManager.NETWORK_PROVIDER）；
试一试{
setText（hereLocation（location.getLatitude（），location.getLatitude（））；
}捕获（例外e）{
Toast.makeText（getApplicationContext（），“未找到！”，
吐司。长度（短）。show（）；
}
}
}
});
}
@凌驾
public void onRequestPermissionsResult（int-requestCode，字符串权限[]，int[]grantResults）{
开关（请求代码）{
案例我的权限请求位置：{
if（grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION\u已授予）{
if（ContextCompat.checkSelfPermission）（MainActivity.this，
Manifest.permission.ACCESS\u\u LOCATION）==PackageManager.permission\u provided）{
LocationManager MLLocationManager=（LocationManager）getSystemService（Context.LOCATION\u服务）；
Location Location=mlLocationManager.getLastKnownLocation（LocationManager.NETWORK_PROVIDER）；
试一试{
setText（hereLocation（location.getLatitude（），location.getLatitude（））；
}捕获（例外e）{
Toast.makeText（getApplicationContext（），“未找到！”，
吐司。长度（短）。show（）；
}
}
}否则{
Toast.makeText（MainActivity.this，“未授予任何权限！”，Toast.LENGTH_SHORT.show（）；
}
返回；
}
}
}
公共管柱位置（双lat、双lng）{
字符串cur_city_name=“”；
地理编码器gcd=新地理编码器（MainActivity.this，
Locale.getDefault（））；
列出地址；
试一试{
地址=gcd.getFromLocation（lat，lng，1）；
如果（地址.size（）>0）
cur_city_name=addresses.get（0.getLocality（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
Toast.makeText（this，“+cur_city_name，Toast.LENGTH_SHORT）.show（）；
返回当前城市名称；
}
}

活动\u main.xml:

package com.example.apple.project;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    private static final int MY_PERMISSIONS_REQUEST_LOCATION = 1;

    TextView textView;

    Button button;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);

        button = (Button) findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (ContextCompat.checkSelfPermission(MainActivity.this,
                        Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                            Manifest.permission.ACCESS_COARSE_LOCATION)) {
                        ActivityCompat.requestPermissions(MainActivity.this,
                                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);
                    } else {
                        ActivityCompat.requestPermissions(MainActivity.this,
                                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);
                    }
                } else {
                    LocationManager mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                    Location location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    try {
                        textView.setText(hereLocation(location.getLatitude(), location.getLongitude()));
                    } catch (Exception e) {
                        Toast.makeText(getApplicationContext(), "Not found!",
                                Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (ContextCompat.checkSelfPermission(MainActivity.this,
                            Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

                        LocationManager mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                        Location location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        try {
                            textView.setText(hereLocation(location.getLatitude(), location.getLongitude()));
                        } catch (Exception e) {
                            Toast.makeText(getApplicationContext(), "Not found!",
                                    Toast.LENGTH_SHORT).show();
                        }

                    }
                } else {
                    Toast.makeText(MainActivity.this, "No permission granted!", Toast.LENGTH_SHORT).show();
                }
                return;
            }
        }
    }

    public String hereLocation(double lat, double lng) {
        String cur_city_name = "";

        Geocoder gcd = new Geocoder(MainActivity.this,
                Locale.getDefault());
        List<Address> addresses;
        try {
            addresses = gcd.getFromLocation(lat, lng, 1);
            if (addresses.size() > 0)
                cur_city_name = addresses.get(0).getLocality();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Toast.makeText(this, "" + cur_city_name, Toast.LENGTH_SHORT).show();
        return cur_city_name;
    }


}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout        
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

请参阅链接

Geocoder gcd=new Geocoder（context，Locale.getDefault（））；
列表地址=gcd.getFromLocation（lat，lng，1）；
如果（地址.size（）>0）
{
System.out.println（addresses.get（0.getLocality（））；
}
其他的
{
//你的员工呢
}

试试这个，它非常好用

 public String getAddress(double lats, double lons) {

                Geocoder geocoder;
                double lat = lats;
                double lon = lons;
                geocoder = new Geocoder(YourActivityName.this, Locale.getDefault());
                List<android.location.Address> addresses = null;
                try {
                    addresses = geocoder.getFromLocation(lat, lon, 1);
                } catch (IOException e) {

                    e.printStackTrace();
                }

                if (addresses != null) {

                    String address = addresses.get(0).getAddressLine(0); 
                    String city = addresses.get(0).getLocality();
                    String state = addresses.get(0).getAdminArea();
                    String country = addresses.get(0).getCountryName();
                    String postalCode = addresses.get(0).getPostalCode();
                    String knownName = addresses.get(0).getFeatureName(); 

                    return address;
                } else {
                    return "failed";
                }


            }

公共字符串getAddress（双lat，双lons）{
地理编码器；
双车床=车床；
双lon=lons；
geocoder=新的geocoder（YourActivityName.this，Locale.getDefault（））；
列表地址=空；
试一试{
地址=地理编码器。getFromLocation（lat，lon，1）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
如果（地址！=null）{
字符串地址=地址.get（0）.getAddressLine（0）；
字符串city=addresses.get（0.getLocation（）；
字符串状态=addresses.get（0.getAdminArea（）；