我一直试图从Android应用程序写入csv文件。但是由于某种原因，我仍然没有得到许可。我已授予该应用程序和仿真器的许可，但似乎找不到该文件，这使我相信未创建该文件。
这是活动。
package com.example.rimartinez.hollanderreborn;
import android.Manifest;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.app.Activity;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.ListView;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;
import com.opencsv.CSVWriter;
import java.io.File;
import java.io.Writer;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;
public class problem extends Activity {
Button submit;
Switch mech_Switch, elect_Switch, clean_Switch;
String lv_Mech[] = new String[] {"Mec1","Mec2","Mec3","Mec4","Mec5","Mec6","Mec7","Mec8","Mec9","Mec10","Mec11"};
String lv_Elect[] = new String[] {"Elec1","Elec2","Elec3","Elec4","Elec5","Elec6","Elec7","Elec8","Elec9","Elec10","Elec11"};
String lv_Clean[] = new String[] {"Clean1","Clean2","Clean3","Clean4","Clean5","Clean6","Clean7","Clean8","Clean9","Clean10","Clean11"};
File file = new File("/sdcard/string_sample.csv");
private static final String STRING_ARRAY_SAMPLE = "/sdcard/string_array_sample.csv";
private int STORAGE_PERMISSION_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.problem_type);
Intent i = getIntent();
final String PMemail = i.getStringExtra("plantManageremail");
final String MMEmail = i.getStringExtra("maintenanceManageremail");
final String Ltype = i.getStringExtra("Ltype");
final String PType = i.getStringExtra("Ptype");
final String LNumber = i.getStringExtra("Lnumber");
final ListView clean_list = (ListView) findViewById(R.id.lv_Cleaning);
final ListView elect_list = (ListView) findViewById(R.id.lv_Electrical);
final ListView mech_list = (ListView) findViewById(R.id.lv_Mechanical);
clean_list.setVisibility(View.GONE);
elect_list.setVisibility(View.GONE);
mech_list.setVisibility(View.GONE);
submit = (Button) findViewById(R.id.btn_submit);
submit.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (ContextCompat.checkSelfPermission(problem.this,
Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(problem.this, "You have already granted this permission!",
Toast.LENGTH_SHORT).show();
} else {
requestStoragePermission();
}
// TODO Auto-generated method stub
new Thread(new Runnable() {
public void run() {
try {
GMailSender sender = new GMailSender(
"email@gmail.com",
"put yourpassword");
sender.sendMail("Production line reported down!", " "+Ltype+" number "+LNumber+" has been reported down due to an "+PType+" related problem",
"darthvadersfavorite@gmail.com",
""+PMemail+","+ MMEmail);
} catch (Exception e) {
Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
}
try {
try (
Writer writer = Files.newBufferedWriter(Paths.get(STRING_ARRAY_SAMPLE));
CSVWriter csvWriter = new CSVWriter(writer,
CSVWriter.DEFAULT_SEPARATOR,
CSVWriter.NO_QUOTE_CHARACTER,
CSVWriter.DEFAULT_ESCAPE_CHARACTER,
CSVWriter.DEFAULT_LINE_END);
)
{
String[] headerRecord = {"Time", "Line Number", "Line Type", "Problem Type"};
csvWriter.writeNext(headerRecord);
csvWriter.writeNext(new String[]{"Sundar Pichai",LNumber, Ltype, PType});
csvWriter.writeNext(new String[]{"Satya Nadella", "satya.nadella@outlook.com", "+1-1111111112", "India"});
}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
});
mech_Switch = (Switch) findViewById(R.id.switch_Mechanical);
elect_Switch = (Switch) findViewById(R.id.switch_Electrical);
clean_Switch = (Switch) findViewById(R.id.switch_Cleaning);
//Mechanical Switch
mech_Switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
elect_Switch.setChecked(false);
clean_Switch.setChecked(false);
mech_list.setVisibility(View.VISIBLE);
clean_list.setVisibility(View.GONE);
elect_list.setVisibility(View.GONE);
}
});
//Electrical Switch
elect_Switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
clean_Switch.setChecked(false);
mech_Switch.setChecked(false);
elect_list.setVisibility(View.VISIBLE);
clean_list.setVisibility(View.GONE);
mech_list.setVisibility(View.GONE);
}
});
//Cleaning Switch
clean_Switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mech_Switch.setChecked(false);
elect_Switch.setChecked(false);
clean_list.setVisibility(View.VISIBLE);
elect_list.setVisibility(View.GONE);
mech_list.setVisibility(View.GONE);
}
});
//Mechanical ListView
ArrayAdapter<String> mech_adapter = new ArrayAdapter<String> (this, android.R.layout.simple_list_item_1, lv_Mech);
mech_list.setAdapter(mech_adapter);
mech_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(problem.this, lv_Mech[position], Toast.LENGTH_SHORT).show();
}
});
//Electrical ListView
ArrayAdapter<String> elect_adapter = new ArrayAdapter<String> (this, android.R.layout.simple_list_item_1, lv_Elect);
elect_list.setAdapter(elect_adapter);
elect_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(problem.this, lv_Elect[position], Toast.LENGTH_SHORT).show();
}
});
//Cleaning ListView
ArrayAdapter<String> clean_adapter = new ArrayAdapter<String> (this, android.R.layout.simple_list_item_1, lv_Clean);
clean_list.setAdapter(clean_adapter);
clean_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(problem.this, lv_Clean[position], Toast.LENGTH_SHORT).show();
}
});
}
private void requestStoragePermission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
new AlertDialog.Builder(this)
.setTitle("Permission needed")
.setMessage("This permission is needed because of this and that")
.setPositiveButton("ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(problem.this,
new String[] {Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION_CODE);
}
})
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.create().show();
} else {
ActivityCompat.requestPermissions(this,
new String[] {Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION_CODE);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == STORAGE_PERMISSION_CODE) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this, "Permission GRANTED", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Permission DENIED", Toast.LENGTH_SHORT).show();
}
}
}
}
有一堆东西不是代码的一部分，但我只是想确保所有东西都在里面以避免混淆。
这是清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.rimartinez.hollanderreborn">
<uses-permission android:name="android.permission.INTERNET">
</uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".login">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity"></activity>
<activity android:name=".line_type_and_number_class"></activity>
<activity android:name=".problem"></activity>
</application>
</manifest>
运行程序后找不到文件。任何帮助将不胜感激。不好意思的代码很抱歉，我是新来的。
谢谢