android - Get app first install time

activity_main.xml

 <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="com.cfsuman.me.androidcodesnippets.MainActivity"     >     <TextView         android:id="@+id/text_view"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text=""         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintLeft_toLeftOf="parent"         app:layout_constraintRight_toRightOf="parent"         app:layout_constraintTop_toTopOf="parent"         app:layout_constraintVertical_bias="0.129"         android:textSize="20sp"         android:textStyle="bold"         />     <Button         android:id="@+id/button"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Get First Install Time"         android:layout_marginTop="54dp"         app:layout_constraintTop_toBottomOf="@+id/text_view"         android:layout_marginRight="8dp"         app:layout_constraintRight_toRightOf="parent"         android:layout_marginLeft="8dp"         app:layout_constraintLeft_toLeftOf="parent"         /> </android.support.constraint.ConstraintLayout> 

MainActivity.java

 package com.cfsuman.me.androidcodesnippets;  import android.app.Activity; import android.content.Context; import android.content.pm.PackageManager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.text.format.DateFormat; import android.view.View; import android.widget.Button; import android.widget.TextView;  import java.util.Date;   public class MainActivity extends AppCompatActivity {     private Context mContext;     private Activity mActivity;      private Button mButton;     private TextView mTextView;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          // Get the application context         mContext = getApplicationContext();         mActivity = MainActivity.this;          // Get the widget reference from xml layout         mButton = (Button) findViewById(R.id.button);         mTextView = (TextView) findViewById(R.id.text_view);          // Set up the button click listener         mButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 try{                     /*                         firstInstallTime                             long firstInstallTime                              The time at which the app was first installed.                             Units are as per currentTimeMillis().                     */                     long installedTime = mContext.getPackageManager()                             .getPackageInfo(mContext.getPackageName(),0)                             .firstInstallTime;                      // Format the date time                     String dateString = DateFormat                                         .format("MM/dd/yyyy hh:mm:ss", new Date(installedTime))                                         .toString();                      // Get the time difference between now and app first install time                     String timeDifference = getTimeDifference(new Date(installedTime));                      // Display the app install date time on text view                     mTextView.setText("First Install Time\n"+dateString);                      // Display app first install time ago                     mTextView.append("\n\n Time ago\n");                     mTextView.append(timeDifference);                 }catch(PackageManager.NameNotFoundException e){                     e.printStackTrace();                 }             }         });     }      // Custom method to get seconds difference between to date objects     protected static int getSecondsDifference(Date then){         Date now = new Date(System.currentTimeMillis());         long dateDiff = now.getTime() - then.getTime();         return (int) dateDiff/1000; // 1000 milliseconds = 1 second     }      // Custom method to get seconds to readable time     protected static String getReadableTime(int seconds){         String readableTime = "";          int hours = (int) seconds / 3600;         int remainder = (int) seconds - hours * 3600;         int mins = remainder / 60;         remainder = remainder - mins * 60;         int secs = remainder;          if(hours>0){             readableTime = hours + " hour ";         }         if(mins>0){             readableTime += mins + " min ";         }         if (secs>0){             readableTime += secs + " sec";         }         return readableTime;     }      // Custom method to get readable time difference between two date objects     protected static String getTimeDifference(Date then){         return getReadableTime(getSecondsDifference(then));     } }