Java ProcessBuilder command() Method

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Description

The Java ProcessBuilder command(List<String> command) method sets this process builder's operating system program and arguments. This method does not make a copy of the command list. Subsequent updates to the list will be reflected in the state of the process builder. It is not checked whether command corresponds to a valid operating system command.

Declaration

Following is the declaration for java.lang.ProcessBuilder.command() method

public ProcessBuilder command(List<String> command)

Parameters

command − The list containing the program and its arguments

Return Value

This method returns this process builder

Exception

NullPointerException − If the argument is null

Getting list of process for Notepad from a Process Builder Example

The following example shows the usage of ProcessBuilder command() method. In this program, we've created a list of Strings and added notepad.exe to it. Using that list, we've initialized a ProcessBuilder instance. Using command(list) method, we've added a list to the ProcessBuilder. Then we've printed the underlying operating system command name and other details.

package com.tutorialspoint;

import java.util.ArrayList;
import java.util.List;

public class ProcessBuilderDemo {

   public static void main(String[] args) {

      // create a new list of arguments for our process
      List<String> list = new ArrayList<>();
      list.add("notepad.exe");

      // create the process builder
      ProcessBuilder pb = new ProcessBuilder(list);

      // add a new argument to the list
      list.add("text.txt");
	  
      // set the command list
      pb.command(list);

      // print the new command list
      System.out.println(pb.command());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

[notepad.exe, text.txt]

Getting list of process for Calculator from a Process Builder Example

The following example shows the usage of ProcessBuilder command() method. In this program, we've created a list of Strings and added calc.exe to it. Using that list, we've initialized a ProcessBuilder instance. Using command(list) method, we've added a list to the ProcessBuilder. Then we've printed the underlying operating system command name and other details.

package com.tutorialspoint;

import java.util.ArrayList;
import java.util.List;

public class ProcessBuilderDemo {

   public static void main(String[] args) {

      // create a new list of arguments for our process
      List<String> list = new ArrayList<>();
      list.add("calc.exe");

      // create the process builder
      ProcessBuilder pb = new ProcessBuilder(list);

      // set the command list
      pb.command(list);

      // print the new command list
      System.out.println(pb.command());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

[calc.exe]

Getting list of process for Windows Explorer from a Process Builder Example

The following example shows the usage of ProcessBuilder command() method. In this program, we've created a list of Strings and added explorer.exe to it. Using that list, we've initialized a ProcessBuilder instance. Using command(list) method, we've added a list to the ProcessBuilder. Then we've printed the underlying operating system command name and other details.

package com.tutorialspoint;

import java.util.ArrayList;
import java.util.List;

public class ProcessBuilderDemo {

   public static void main(String[] args) {

      // create a new list of arguments for our process
      List<String> list = new ArrayList<>();
      list.add("explorer.exe");

      // create the process builder
      ProcessBuilder pb = new ProcessBuilder(list);
	  
      // set the command list
      pb.command(list);

      // print the new command list
      System.out.println(pb.command());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

[explorer.exe]