Android Tutorials - Herong's Tutorial Examples - v3.05, by Herong Yang
android.os.Environment Class - Environment Folders
This section provides tutorial example on how to display environment folders: data, external storage, download cache, and root folders using the android.os.Environment class.
Another Android class, android.os.Environment, can also be used to retrieve environment folder information as shown in the following example:
/* AboutAndroid.java
* Version 5.0 - Adding environment folders
* 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";
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:
Data folder: /data Download cache folder: /cache External storage folder: /storage/sdcard Root folder: /system
Below was some system properties I got from my Android 4.0.3 emulator created with Android SDK R17:
Data folder: /data Download cache folder: /cache External storage folder: /mnt/sdcard Root folder: /system
Table of Contents
Installing JDK 1.8 on Windows System
Installation of Android SDK R24 and Emulator
Installing Apache Ant 1.9 on Windows System
Developing First Android Application - HelloAndroid
Android Application Package (APK) Files
Android Debug Bridge (adb) Tool
►AboutAndroid - Application to Retrieve System Information
java.lang.System Class - Accessing System Information
Creating Android Project for Simple Application
Build, Install and Run Android Application
System.getProperties() - Retrieving System Properties
android.widget.ScrollView Class - Scrolling Text View
System.getenv() Method - System Environment Variables
►android.os.Environment Class - Environment Folders
android.content.Context - Application Context Information
android.app.Activity Class and Activity Lifecycle
View Objects and Layout Resource Files
Using "adb logcat" Command for Debugging
Build Process and Package File Content
Samsung Galaxy Tab 3 Mini Tablet
USB Debugging Applications on Samsung Tablet
USB Debugging Applications on LG-V905R Tablet