Unresolved import processing.serial

I am trying to execute Example 7-1 from the book Getting Started with Arduino, 3rd Edition. I am using Java below is an excerpt from the start of the code. I am unable to resolve the library reference to the statement import processing.serial.*;. Here is the code:

package arduinoChapter7;

import processing.serial.*; import processing.core.PApplet; import java.net.*; import java.io.*; import java.util.*;

public class Example7_1 {

String feed = "http://makezine.com/feed/";

int interval = 5 * 60 * 1000;  // retrieve feed every five minutes;
int lastTime;                  // the last time we fetched the content

int love    = 0;
int peace   = 0;
int arduino = 0;

int light = 0;  // light level measured by the lamp

Serial port;
color c;
String cs;

String buffer = ""; // Accumulates characters coming from Arduino

PFont font;