Bruce Brouwer created LANG-1062:
-----------------------------------
Summary: Use Java 8 features to improve EqualsBuilder
Key: LANG-1062
URL: https://issues.apache.org/jira/browse/LANG-1062
Project: Commons Lang
Issue Type: Improvement
Components: lang.builder.*
Affects Versions: 3.3.2
Reporter: Bruce Brouwer
Remove the need for boilerplate code still necessary with EqualsBuilder.
Instead of checking for instanceOf or equality checks, it would be nice to be
able to write this:
{code}
public boolean equals(final Object obj) {
return EqualsBuilder.test(this, obj).append(this.id, o -> o.id).isEquals();
}
{code}
I think this could generally work with a subclass of EqualsBuilder with a
generic type, like this:
{code}
public class LambdaEqualsBuilder<T> extends EqualsBuilder {
private final T obj;
public LambdaEqualsBuilder(final T _this, final Object obj) {
if (_this != obj && !_this.getClass().isInstance(obj)) {
appendSuper(false);
this.obj = null;
} else {
this.obj = (T) obj;
}
}
public <P> LambdaEqualsBuilder<T> append(final P a, final Function<T, P> b)
{
if (isEquals()) {
return (LambdaEqualsBuilder<T>) append(a, b.apply(obj));
}
return this;
}
// This might actually go in EqualsBuilder itself
public static <E> LambdaEqualsBuilder<E> test(final E _this, final Object
_that) {
return new LambdaEqualsBuilder<E>(_this, _that);
}
}
{code}
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