How to get running processes in android

activity_main.xml

 <?xml version="1.0" encoding="utf-8"?> <RelativeLayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:padding="16dp"     tools:context=".MainActivity"     android:background="#eff6ff"     >     <ScrollView         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:scrollbars="vertical"         >         <TextView             android:id="@+id/tv"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             />     </ScrollView>     <Button         android:id="@+id/btn"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Run"         android:layout_alignParentBottom="true"         android:layout_alignParentRight="true"         android:layout_alignParentEnd="true"         android:background="#5ea8f7"         /> </RelativeLayout> 

MainActivity.java

 package com.cfsuman.me.androidcode;  import android.app.ActivityManager; import android.content.Context; import android.graphics.Color; import android.graphics.drawable.ColorDrawable; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.support.v7.widget.RecyclerView; import android.view.View; import android.view.Window; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; import java.util.List;   public class MainActivity extends AppCompatActivity {     private Context mContext;      private Button mButton;     private TextView mTextView;       @Override     protected void onCreate(Bundle savedInstanceState) {         // Request window feature action kafe         requestWindowFeature(Window.FEATURE_ACTION_BAR);         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          // Get the application context         mContext = getApplicationContext();          // Set the action kafe color         getSupportActionBar().setBackgroundDrawable(new ColorDrawable(Color.RED));          // Get the widgets reference from XML layout         mButton = (Button) findViewById(R.id.btn);         mTextView = (TextView) findViewById(R.id.tv);          // Set a click listener for button widget         mButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 // Empty the TextView                 mTextView.setText("");                  /*                     ActivityManager                         Interact with the overall activities running in the system.                 */                  // Initialize a new instance of ActivityManager                 ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);                  /*                     ActivityManager.RunningAppProcessInfo                         Information you can retrieve about a running process.                 */                  /*                     public List<ActivityManager.RunningAppProcessInfo> getRunningAppProcesses ()                         Returns a list of application processes that are running on the device.                         Note: this method is only intended for debugging or building a user-facing                         process management UI.                      Returns                         Returns a list of RunningAppProcessInfo records, or null if there are no                         running processes (it will not return an empty list). This list ordering                         is not specified.                 */                 List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();                  // Display the number of running processes                 Toast.makeText(mContext,"Processes : " + runningProcesses.size(),Toast.LENGTH_SHORT).show();                  // Loop through the running processes                 for(ActivityManager.RunningAppProcessInfo processInfo: runningProcesses ){                     // Get the process name                     mTextView.setText(mTextView.getText() + processInfo.processName + "\n");                 }             }         });     } }