PROBLEM
Let’s assume we want to create the default equals(), hashCode() and toString() with the following bean:-
public final class Person {
private final String name;
private final Collection<car> cars;
public Person(final String name, final Collection<car> cars) {
this.name = name;
this.cars = cars;
}
public String getName() {
return name;
}
public Collection<car> getCars() {
return cars;
}
}
Most IDEs, including older version of IntelliJ, have code generation features that would create something similar to this:-
public final class Person {
...
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
final Person person = (Person) o;
if (name != null ? !name.equals(person.name) : person.name != null) {
return false;
}
return !(cars != null ? !cars.equals(person.cars) : person.cars != null);
}
@Override
public int hashCode() {
int result = name != null ? name.hashCode() : 0;
result = 31 * result + (cars != null ? cars.hashCode() : 0);
return result;
}
@Override
public String toString() {
return "Person{" +
"name='" + name + '\'' +
", cars=" + cars +
'}';
}
}
While it works, the generated code is usually crazy horrendous.
SOLUTION
With IntelliJ 14.x, it allows us to select templates from several proven libraries.
To generate equals() and hashCode(), select equals() and hashCode() option from the Generate pop-up dialog:-
There are several templates to choose from:-
Here’s an example of equals() and hashCode() using Guava and getter methods:-
public final class Person {
...
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
final Person person = (Person) o;
return Objects.equal(getName(), person.getName()) &amp;&amp;
Objects.equal(getCars(), person.getCars());
}
@Override
public int hashCode() {
return Objects.hashCode(getName(), getCars());
}
}
To generate toString(), select toString() option from the Generate pop-up dialog:-
Again, there are several templates to choose from:-
Here’s an example of toString() using Guava:-
public final class Person {
...
@Override
public String toString() {
return Objects.toStringHelper(this)
.add("name", name)
.add("cars", cars)
.toString();
}
}