Reading CSV File In Android App

Question

I'm working on a proof-of-concept app so that I can implement the feature in a larger app I'm making. I'm a bit new to Java and Android Dev but hopefully this shouldn't be too simple or complex of a question.

Basically, I'm trying to read in a list of strings from a CSV file and make it usable in displaying the list on the app's Main Activity.

I'm using an external class for reading in CSV's. Here's the class code:

CSVFile.java

package com.yourtechwhiz.listdisplay;  import android.util.Log;  import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List;  public class CSVFile {     InputStream inputStream;      public CSVFile(InputStream inputStream){         this.inputStream = inputStream;     }      public List read(){         List resultList = new ArrayList();         BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));         try {             String csvLine;             while ((csvLine = reader.readLine()) != null) {                 String[] row = csvLine.split(",");                 resultList.add(row);                 Log.d("VariableTag", row[0].toString());             }         }         catch (IOException ex) {             throw new RuntimeException("Error in reading CSV file: "+ex);         }         finally {             try {                 inputStream.close();             }             catch (IOException e) {                 throw new RuntimeException("Error while closing input stream: "+e);             }         }         return resultList;     } } 

Here's my main activity code:

MainActivity.java

package com.yourtechwhiz.listdisplay;  import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.widget.ArrayAdapter; import android.widget.ListView;  import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List;  public class MainActivity extends AppCompatActivity {      // Array of strings that's used to display on screen     String[] mobileArray = {"Android","IPhone","WindowsMobile","Blackberry",             "WebOS","Ubuntu","Windows7","Max OS X"};      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          prepArray();          //Display List on Activity         ArrayAdapter adapter = new ArrayAdapter<String>(this,                 R.layout.activity_listview, mobileArray);         ListView listView = (ListView) findViewById(R.id.mobile_list);         listView.setAdapter(adapter);      }      //Get list of strings from CSV ready to use     private void prepArray() {          InputStream inputStream = getResources().openRawResource(R.raw.strings);         CSVFile csvFile = new CSVFile(inputStream);         List myList = csvFile.read();          //This is where it has an error         //Set first array in myList to this new array myArray         String[] myArray = myList.get(0);      }  } 

I'm not actually to the point of setting the mobileArray array yet. Right now I'm just trying to "extract" the information out of the List object myList...

Can someone explain to me how this is done? Maybe I'm just not understanding the List type completely. It seems like when resultList is returned in the CSVFile read method, it's returned as an List object consisting of String array objects. But I can't seem to get it to work like that.

Any help is appreciated!

FINAL EDIT (working code)

private void prepArray() {          try{             CSVReader reader = new CSVReader(new InputStreamReader(getResources().openRawResource(R.raw.strings)));//Specify asset file name             String [] nextLine;             while ((nextLine = reader.readNext()) != null) {                 // nextLine[] is an array of values from the line                 System.out.println(nextLine[0] + nextLine[1] + "etc...");                 Log.d("VariableTag", nextLine[0]);             }         }catch(Exception e){             e.printStackTrace();             Toast.makeText(this, "The specified file was not found", Toast.LENGTH_SHORT).show();         }      } 

EDIT

Now my prepArray function looks like the following:

    private void prepArray() {          try{             String csvfileString = this.getApplicationInfo().dataDir + File.separatorChar + "strings.csv"             File csvfile = new File(csvfileString);             CSVReader reader = new CSVReader(new FileReader("csvfile.getAbsolutePath()"));             String [] nextLine;             while ((nextLine = reader.readNext()) != null) {                 // nextLine[] is an array of values from the line                 System.out.println(nextLine[0] + nextLine[1] + "etc...");             }         }catch(FileNotFoundException e){             e.printStackTrace();             Toast.makeText(this, "The specified file was not found", Toast.LENGTH_SHORT).show();         }      } 

Still produces the FileNotFoundException.

EDIT 2/3

Here's the log that's produced when I run the app on an actual phone with the strings.csv in a subfolder of strings (src\main\assets\strings\strings.csv) with the change you requested to the code:

03/27 17:44:01: Launching app         $ adb push C:\Users\Roy\AndroidStudioProjects\ListDisplay\app\build\outputs\apk\app-debug.apk /data/local/tmp/com.yourtechwhiz.listdisplay         $ adb shell pm install -r "/data/local/tmp/com.yourtechwhiz.listdisplay"         pkg: /data/local/tmp/com.yourtechwhiz.listdisplay         Success           $ adb shell am start -n "com.yourtechwhiz.listdisplay/com.yourtechwhiz.listdisplay.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER -D         Connecting to com.yourtechwhiz.listdisplay         D/HyLog: I : /data/font/config/sfconfig.dat, No such file or directory (2)         D/HyLog: I : /data/font/config/dfactpre.dat, No such file or directory (2)         D/HyLog: I : /data/font/config/sfconfig.dat, No such file or directory (2)         W/ActivityThread: Application com.yourtechwhiz.listdisplay is waiting for the debugger on port 8100...         I/System.out: Sending WAIT chunk         I/dalvikvm: Debugger is active         I/System.out: Debugger has connected         I/System.out: waiting for debugger to settle...         Connected to the target VM, address: 'localhost:8609', transport: 'socket'         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: waiting for debugger to settle...         I/System.out: debugger has settled (1498)         I/dalvikvm: Could not find method android.view.Window$Callback.onProvideKeyboardShortcuts, referenced from method android.support.v7.view.WindowCallbackWrapper.onProvideKeyboardShortcuts         W/dalvikvm: VFY: unable to resolve interface method 16152: Landroid/view/Window$Callback;.onProvideKeyboardShortcuts (Ljava/util/List;Landroid/view/Menu;I)V         D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002         W/dalvikvm: VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)         I/dalvikvm: Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested         W/dalvikvm: VFY: unable to resolve interface method 16154: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z         D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002         I/dalvikvm: Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode         W/dalvikvm: VFY: unable to resolve interface method 16158: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;         D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002         I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations         W/dalvikvm: VFY: unable to resolve virtual method 455: Landroid/content/res/TypedArray;.getChangingConfigurations ()I         D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002         I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType         W/dalvikvm: VFY: unable to resolve virtual method 477: Landroid/content/res/TypedArray;.getType (I)I         D/dalvikvm: VFY: replacing opcode 0x6e at 0x0008         I/dalvikvm: Could not find method android.widget.FrameLayout.startActionModeForChild, referenced from method android.support.v7.widget.ActionBarContainer.startActionModeForChild         W/dalvikvm: VFY: unable to resolve virtual method 16589: Landroid/widget/FrameLayout;.startActionModeForChild (Landroid/view/View;Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;         D/dalvikvm: VFY: replacing opcode 0x6f at 0x0002         I/dalvikvm: Could not find method android.content.Context.getColorStateList, referenced from method android.support.v7.content.res.AppCompatResources.getColorStateList         W/dalvikvm: VFY: unable to resolve virtual method 269: Landroid/content/Context;.getColorStateList (I)Landroid/content/res/ColorStateList;         D/dalvikvm: VFY: replacing opcode 0x6e at 0x0006         I/dalvikvm: Could not find method android.content.res.Resources.getDrawable, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawable         W/dalvikvm: VFY: unable to resolve virtual method 418: Landroid/content/res/Resources;.getDrawable (ILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable;         D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002         I/dalvikvm: Could not find method android.content.res.Resources.getDrawableForDensity, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawableForDensity         W/dalvikvm: VFY: unable to resolve virtual method 420: Landroid/content/res/Resources;.getDrawableForDensity (IILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable;         D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002         E/dalvikvm: Could not find class 'android.graphics.drawable.RippleDrawable', referenced from method android.support.v7.widget.AppCompatImageHelper.hasOverlappingRendering         W/dalvikvm: VFY: unable to resolve instanceof 140 (Landroid/graphics/drawable/RippleDrawable;) in Landroid/support/v7/widget/AppCompatImageHelper;         D/dalvikvm: VFY: replacing opcode 0x20 at 0x000c         W/System.err: java.io.FileNotFoundException: /csvfile.getAbsolutePath(): open failed: ENOENT (No such file or directory)         W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:462)         W/System.err:     at java.io.FileInputStream.<init>(FileInputStream.java:78)         W/System.err:     at java.io.FileInputStream.<init>(FileInputStream.java:105)         W/System.err:     at java.io.FileReader.<init>(FileReader.java:66)         W/System.err:     at com.yourtechwhiz.listdisplay.MainActivity.prepArray(MainActivity.java:43)         W/System.err:     at com.yourtechwhiz.listdisplay.MainActivity.onCreate(MainActivity.java:26)         W/System.err:     at android.app.Activity.performCreate(Activity.java:5287)         W/System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)         W/System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2145)         W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2231)         W/System.err:     at android.app.ActivityThread.access$700(ActivityThread.java:139)         W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1401)         W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)         W/System.err:     at android.os.Looper.loop(Looper.java:137)         W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5082)         W/System.err:     at java.lang.reflect.Method.invokeNative(Native Method)         W/System.err:     at java.lang.reflect.Method.invoke(Method.java:515)         W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)         W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:598)         W/System.err:     at dalvik.system.NativeStart.main(Native Method)         W/System.err: Caused by: libcore.io.ErrnoException: open failed: ENOENT (No such file or directory)         W/System.err:     at libcore.io.Posix.open(Native Method)         W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)         W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:446)         W/System.err:   ... 19 more         I/Adreno-EGL: <qeglDrvAPI_eglInitialize:385>: EGL 1.4 QUALCOMM build:  ()         OpenGL ES Shader Compiler Version: E031.24.00.01         Build Date: 12/27/13 Fri         Local Branch: qualcomm_only         Remote Branch:         Local Patches:         Reconstruct Branch:         D/OpenGLRenderer: Enabling debug mode 0         D/OpenGLRenderer: GL error from OpenGLRenderer: 0x502         E/OpenGLRenderer:   GL_INVALID_OPERATION 

Answer 1

Try OpenCSV - it will make your life easier.

First, add this package to your gradle dependencies as follows

implementation 'com.opencsv:opencsv:4.6' 

Then you can either do

import com.opencsv.CSVReader; import java.io.IOException; import java.io.FileReader;   ...  try {     CSVReader reader = new CSVReader(new FileReader("yourfile.csv"));     String[] nextLine;     while ((nextLine = reader.readNext()) != null) {         // nextLine[] is an array of values from the line         System.out.println(nextLine[0] + nextLine[1] + "etc...");     } } catch (IOException e) {  } 

or

CSVReader reader = new CSVReader(new FileReader("yourfile.csv")); List myEntries = reader.readAll(); 

---

Edit after comment

try {     File csvfile = new File(Environment.getExternalStorageDirectory() + "/csvfile.csv");     CSVReader reader = new CSVReader(new FileReader(csvfile.getAbsolutePath()));     String[] nextLine;     while ((nextLine = reader.readNext()) != null) {         // nextLine[] is an array of values from the line         System.out.println(nextLine[0] + nextLine[1] + "etc...");     } } catch (Exception e) {     e.printStackTrace();     Toast.makeText(this, "The specified file was not found", Toast.LENGTH_SHORT).show(); } 

If you want to package the .csv file with the application and have it install on the internal storage when the app installs, create an assets folder in your project src/main folder (e.g., c:\myapp\app\src\main\assets\), and put the .csv file in there, then reference it like this in your activity:

String csvfileString = this.getApplicationInfo().dataDir + File.separatorChar + "csvfile.csv" File csvfile = new File(csvfileString);