How to Verify DropDown Values Are In Sorting Order Using Java Selenium?

Verify DropDown Values Using Selenium

How to Verify Drop Down Values Are In Sorting Order Using Java Selenium?

package com.selenium.mix;
import static org.junit.Assert.*;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
public class DropDownListSortedOrNot {
   @Test
   public void dropDownListSortedOrNot() throws InterruptedException {
      WebDriver driver = new FirefoxDriver();
      driver.get("http://www.ebay.in/");
      Thread.sleep(3000);  
      WebElement element = driver.findElement(By.id("gh-cat"));
      element.click();
      List<WebElement> dropDownvalues = element.findElements(By.tagName("option"));
      ArrayList<String> listValues = new ArrayList<String>();
      for(WebElement value : dropDownvalues) {
         System.out.println("values are"+ value.getText());
         listValues.add(value.getText());
      }
      boolean sortedOrNot = sortedOrNot(listValues);
      assertEquals(true, sortedOrNot);
      driver.close();

   }
   public boolean sortedOrNot(ArrayList<String> dropDownValues) {
      System.out.println("number of values "+ dropDownValues.size());
      for(int i=0; i<dropDownValues.size();i++) {
         int temp = dropDownValues.get(i).compareTo(dropDownValues.get(i+1));
         if(temp>1) {
            System.out.println("i value"+i);
            return false;
         }
      }
      return true; 
   }
}