Answer:
See solution below
See comments for explanations
Explanation:
import java.util.*;
class Main {
  public static void main(String[] args) {
    //PrompT the User to enter a String
    System.out.println("Enter a sentence or phrase: ");
    //Receiving the string entered with the Scanner Object
    Scanner input = new Scanner (System.in);
    String string_input = input.nextLine();
    //Print out string entered by user
    System.out.println("You entered: "+string_input);
    //Call the first method (GetNumOfCharacters)
    System.out.println("Number of characters: "+ GetNumOfCharacters(string_input));
    //Call the second method (OutputWithoutWhitespace)
    System.out.println("String with no whitespace: "+OutputWithoutWhitespace(string_input));
    }
  //Create the method GetNumOfCharacters
    public static int GetNumOfCharacters (String word) {
    //Variable to hold number of characters
    int noOfCharactersCount = 0;
    //Use a for loop to iterate the entire string
    for(int i = 0; i< word.length(); i++){
      //Increase th number of characters each time
      noOfCharactersCount++;
    }
    return noOfCharactersCount;
  }
  //Creating the OutputWithoutWhitespace() method
  //This method will remove all tabs and spaces from the original string
  public static String OutputWithoutWhitespace(String word){
    //Use the replaceAll all method of strings to replace all whitespaces
    String stringWithoutWhiteSpace = word.replaceAll(" ","");
    return stringWithoutWhiteSpace;
  }
}