android.content.Context - Application Context Information

Android Tutorials - Herong's Tutorial Examples

∟AboutAndroid - Application to Retrieve System Information

∟android.content.Context - Application Context Information

This section provides tutorial example on how to display application context information using instance methods of the android.content.Context class like application package name, private file folder, private cache folder, etc.

For information about the running application itself, the android.app.Activity object inherits some useful instance methods from the android.content.Context class:

abstract String[] fileList() - Returns an array of strings naming the private files associated with this Context's application package.
abstract File getCacheDir() - Returns the absolute path to the application specific cache directory on the filesystem.
abstract File getExternalCacheDir() - Returns the absolute path to the directory on the external filesystem (that is somewhere on Environment.getExternalStorageDirectory() where the application can place cache files it owns.
abstract File getFilesDir() - Returns the absolute path to the directory on the filesystem where files created with openFileOutput(String, int) are stored.
abstract File getObbDir() - Return the directory where this application's OBB (Opaque Binary Blob) files (if there are any) can be found.
abstract String getPackageCodePath() - Return the full path to this context's primary Android package.
abstract String getPackageName() - Return the name of this application's package.
abstract String getPackageResourcePath() - Return the full path to this context's primary Android package.

I enhanced again my AboutAndroid application to display its context information using methods listed above:

/* AboutAndroid.java
 * Version 6.0 - Adding application context info
 * Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
package com.herongyang;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.ScrollView;
import android.os.Environment;
public class AboutAndroid extends Activity {
   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      String msg = "";

      msg += "System properties\n";
      msg += "-------------\n";
      java.util.Properties props = System.getProperties();
      java.util.Enumeration e = props.propertyNames();
      while (e.hasMoreElements()) {
         String k = (String) e.nextElement();
         String v = props.getProperty(k);
         msg += k+": "+v+"\n";
      }

      msg += "\n";
      msg += "Environment variables\n";
      msg += "-------------\n";
      java.util.Map envs = System.getenv();
      java.util.Set keys = envs.keySet();
      java.util.Iterator i = keys.iterator();
      while (i.hasNext()) {
         String k = (String) i.next();
         String v = (String) envs.get(k);
         msg += k+": "+v+"\n";
      }

      msg += "\n";
      msg += "Environment folders\n";
      msg += "-------------\n";
      msg += "Data folder: "
         +Environment.getDataDirectory().getPath()+"\n";
      msg += "Download cache folder: "
         +Environment.getDownloadCacheDirectory().getPath()+"\n";
      msg += "External Storage folder: "
         +Environment.getExternalStorageDirectory().getPath()+"\n";
      msg += "Root folder: "
         +Environment.getRootDirectory().getPath()+"\n";

      msg += "\n";
      msg += "Application context info\n";
      msg += "-------------\n";
      msg += "Cache folder: "
         +getCacheDir().getPath()+"\n";
      msg += "External cache folder: "
         +getExternalCacheDir().getPath()+"\n";
      msg += "File folder: "
         +getFilesDir().getPath()+"\n";
      msg += "OBB folder: "
         +getObbDir().getPath()+"\n";
      msg += "Package name: "
         +getPackageName()+"\n";
      msg += "Package code path: "
         +getPackageCodePath()+"\n";
      msg += "Package resource path: "
         +getPackageResourcePath()+"\n";

      TextView tv = new TextView(this);
      tv.setText(msg);
      ScrollView sv = new ScrollView(this);
      sv.addView(tv);
      setContentView(sv);
   }
}

2. Uninstall the previous version, build, install and run this new version. I get the following extra information at the end:

Cache folder: /data/data/com.herongyang/cache
External cache folder: /storage/sdcard/Android/data/com.herongyang/cache
File folder: /data/data/com.herongyang/files
OBB folder: /storage/sdcard/Android/obb/com.herongyang
Package name: com.herongyang
Package code path: /data/app/com.herongyang-1/base.apk
Package resource path: /data/app/com.herongyang-1/base.apk

Below was some system properties I got from my Android 4.0.3 emulator created with Android SDK R17:

Cache folder: /data/data/com.herongyang/cache
External cache folder: /mnt/sdcard/Android/data/com.herongyang/cache
File folder: /data/data/com.herongyang/files
OBB folder: /mnt/sdcard/Android/obb/com.herongyang
Package name: com.herongyang
Package code path: /data/app/com.herongyang-1.apk
Package resource path: /data/app/com.herongyang-1.apk