Implementing compareTo() using commons-lang

Here CompareToBuilder is used to implement compareTo();

public int compareTo(Person person) {
    return new CompareToBuilder()
    append(this.firstName, person.firstName)
    append(this.lastName, person.firstName)
    toComparison();
}

Also, there is yet another reflection option:

public int compareTo(Object o) {
    return CompareToBuilder.reflectionCompare(this, o);
}

Implementing hashCode using commons-lang

This example shows how to implement hashCode() using HashCodeBuilder of commons-lang.

import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.EqualsBuilder;

import java.io.Serializable;

public class MyClass implements Serializable {
  private Long id;

  private String title;

  private String author;

  public int hashCode() {
    return new HashCodeBuilder().append(id).append(title).append(author).toHashCode();

    // return HashCodeBuilder.reflectionHashCode(this);

  }
}

 

Also, reflection can be used to implement the same function:

public int hashCode() {
    return HashCodeBuilder.reflectionHashCode(this);
}

Implement equals method using commons-lang

Here we use EqualsBuilder to see whether the 2 objects are equal or not. Take the example of person:

import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.EqualsBuilder;

import java.io.Serializable;

public class Person implements Serializable {
  private Long id;

  private String name;

  private String sirname;

  public boolean equals(Object object) {
    if (!(object instanceof Main)) {
      return false;
    }

    if (object == this) {
      return true;
    }

    Person person = (Person) object;
    return new EqualsBuilder().append(this.id, person.id).append(this.name, person.name)
              .append(this.sirname, person.sirname).isEquals();

    // return EqualsBuilder.reflectionEquals(this, person);

  }
}