public class Person implements Comparable<Person>
{

String name;
int age;
String mail;

public String getMail() {
    return mail;
}

public void setMail(String mail) {
    this.mail = mail;
}

public Person(String name, int age, String mail) {
    this.name = name;
    this.age = age;
}

public String getName() {
    return name;
}

public int getAge() {
    return age;
}

public String toString() {
    return name + " : " + age;
}

public int compareTo(Person p) {
    return getMail().compareTo(p.getMail());
}
// wants to re-write this method
@Override
public boolean equals(Object obj) {
    if (this == obj) {
        return true;
    }
    if (obj == null) {
        return false;
    }
    if (getClass() != obj.getClass()) {
        return false;
    }
    return false;
}

public static void main(String[] args) {
    List<Person> people = new ArrayList<Person>();
    people.add(new Person("Homer", 38, "shankar@gmail.com"));
    people.add(new Person("Marge", 35, "shankar6@gmail.com"));
    people.add(new Person("Bart", 15, "ramr@gmail.com"));
    people.add(new Person("Lisa", 13, "ramkumar@gmail.com"));

    /*
     * Collections.sort(people, new Person.AgeComparator());
     * System.out.println("Sort using Age Comparator");
     */
    System.out.println("t" + people);

    List<Person> people1 = new ArrayList<Person>();
    people1.add(new Person("jug", 38, "jug@gmail.com"));
    people1.add(new Person("benny", 35, "benny@gmail.com"));
    people1.add(new Person("Bart", 15, "ramr@gmail.com"));
    people1.add(new Person("Lisa", 13, "ramkumar@gmail.com"));

    for (Person people: people) {
        // WIHTHOUT ITERATING people1 i want to compare against people object
        if(people==people1)
         {
        System.out.println(" matched");
        System.out.println(people);
         }
        else
         {
           System.out.println("not matched");
        System.out.println(people);
         }
    }

}

matched
 Bart : 15 :ramr@gmail.com