public boolean removeAll(Collection c)

Parameters: 

// Java program to Remove One Array From Another Array

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

class GFG {
	public static void main(String[] args)
	{

		// creating first array
		List firstList = new ArrayList<>();

		// creating second array
		List secondList = new ArrayList<>();

		// adding elements in first array
		firstList.add(100);
		firstList.add(200);
		firstList.add(300);
		firstList.add(400);
		firstList.add(500);
		firstList.add(600);

		// adding elements in second array
		secondList.add(300);
		secondList.add(500);
		
		// displaying element of first array
		System.out.println("elements in first array "
						+ firstList);
		
		// displaying element of second array
		System.out.println("elements in second array "
						+ secondList);
		
		// removing elements from firstarray
		firstList.removeAll(secondList);

		// displaying elements of first array
		// after removing elements of second array
		// from first array
		System.out.println("first array after removing second array from first array\n"
			+ firstList);
	}
}

Output

elements in first array [100, 200, 300, 400, 500, 600]
elements in second array [300, 500]
first array after removing second array from first array
[100, 200, 400, 600]

Example 2:

// Java program to Remove One Array From Another Array

import java.io.*;
import java.util.*;

class friendsDetail {

	// class field
	private String name;
	private String nickName;

	// parameterised constructor
	public friendsDetail(String name, String nickName)
	{
		this.name = name;
		this.nickName = nickName;
	}

	// getter for name
	public String getName() { return name; }

	// setter for name
	public void setName(String name) { this.name = name; }

	// getter for nickname
	public String getnickName() { return nickName; }

	// setter for nickname
	public void setNickName(int id)
	{
		this.nickName = nickName;
	}

	@Override public boolean equals(Object o)
	{

		if (this == o)
			return true;

		if (!(o instanceof friendsDetail))
			return false;

		friendsDetail that = (friendsDetail)o;

		return Objects.equals(getName(), that.getName())
			&& Objects.equals(nickName, that.nickName);
	}

	@Override public int hashCode()
	{
		return Objects.hash(getName(), nickName);
	}

	// overriding toString method
	public String toString()
	{
		// return super.toString();
		return "(" + this.getName() + ":"
						+ this.getnickName() + ")";
	}
}
public class GFG {
	public static void main(String[] args)
	{
		ArrayList firstArrayList = new ArrayList<>();

		System.out.println("Our First ArrayList\n");

		// adding elements to first ArrayList
		firstArrayList.add(new friendsDetail("Amit", "Ghulla"));
		firstArrayList.add(new friendsDetail("Yashdeep", "Dopa"));
		firstArrayList.add(new friendsDetail("Jyoti", "Kauwa"));
		firstArrayList.add(new friendsDetail("Suraj", "Bhindi"));
		firstArrayList.add(new friendsDetail("Himanshu", "Lalten"));
		firstArrayList.add(new friendsDetail("Sarthak", "Nagin"));
		firstArrayList.add(new friendsDetail("Tsering", "Battak"));
		firstArrayList.add(new friendsDetail("Abhishek", "Liquid"));

		// Displaying output of first array using enhanced
		// for loop
		for (friendsDetail friend : firstArrayList) {
			System.out.println(friend);
		}

		ArrayList secondArrayList = new ArrayList<>();

		System.out.println("\nOur Second ArrayList\n");
		
		// adding elements to second ArrayList.
		secondArrayList.add(new friendsDetail("Amit", "Ghulla"));
		secondArrayList.add(new friendsDetail("Jyoti", "Kauwa"));
		secondArrayList.add(new friendsDetail("Himanshu", "Lalten"));
		secondArrayList.add(new friendsDetail("Abhishek", "Liquid"));

		// Displaying output of original array using
		// enhanced for loop
		for (friendsDetail friend : secondArrayList) {
			System.out.println(friend);
		}

		// removing second array elements from first array
		firstArrayList.removeAll(secondArrayList);

		System.out.println(
		"\nFirst array after removing second array from first array\n");

		// Displaying first array after removing second
		// array elements from first array
		for (friendsDetail friend : firstArrayList) {
			System.out.println(friend);
		}
	}
}

Output

Our First ArrayList

(Amit:Ghulla)
(Yashdeep:Dopa)
(Jyoti:Kauwa)
(Suraj:Bhindi)
(Himanshu:Lalten)
(Sarthak:Nagin)
(Tsering:Battak)
(Abhishek:Liquid)

Our Second ArrayList

(Amit:Ghulla)
(Jyoti:Kauwa)
(Himanshu:Lalten)
(Abhishek:Liquid)

First array after removing second array from first array

(Yashdeep:Dopa)
(Suraj:Bhindi)
(Sarthak:Nagin)
(Tsering:Battak)