[
https://issues.apache.org/jira/browse/LANG-1113?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Simon Meyffret updated LANG-1113:
---------------------------------
Description:
As explained by LANG-393 and LANG-467, {{EqualsBuilder}} fails to provide a
proper way to handle {{BigDecimal}} since {{BigDecimal}} takes the scale into
account when using {{equals()}} but not with {{compareTo()}}.
Would it be possible to add a method *{{appendComparable()}}* in
{{EqualsBuilder}} to manages {{Comparable}} objects when we want to build
equality on {{compareTo()}} and not {{equals()}}?
Making clear that {{EqualsBuilder}} is not compliant with {{HashCodeBuilder}}
when using this method.
For example:
{code:borderStyle=solid}
return new EqualsBuilder()
.append(this.name, other.name)
.appendComparable(this.amount, other.amount)
.isEqual();
{code}
with:
{code:title=EqualsBuilder.java|borderStyle=solid}
/**
* <p>Test if two <code>Comparable</code>s are equal using their
* <code>compareTo</code> method.</p>
* <p>This may break the <code>equals</code>/<code>hashcode</code>
contract but
* it is useful in some situation, specially with {@link
java.math.BigDecimal}.</p>
*
* @param lhs the left hand comparable
* @param rhs the right hand comparable
* @return EqualsBuilder - used to chain calls.
*/
public <T extends Comparable<? super T>> EqualsBuilder
appendComparable(T lhs, T rhs) {
if (isEquals == false) {
return this;
}
if (lhs == rhs) {
return this;
}
if (lhs == null || rhs == null) {
isEquals = false;
return this;
} else if (lhs.compareTo(rhs) != 0) {
isEquals = false;
return this;
}
return this;
}
/**
* <p>Performs a deep comparison of two <code>Comparable</code>
arrays.</p>
*
* @param lhs the left hand <code>Comparable[]</code>
* @param rhs the right hand <code>Comparable[]</code>
* @return EqualsBuilder - used to chain calls.
* @see #appendComparable(Comparable, Comparable)
*/
public <T extends Comparable<? super T>> EqualsBuilder
appendComparable(T[] lhs, T[] rhs) {
if (isEquals == false) {
return this;
}
if (lhs == rhs) {
return this;
}
if (lhs == null || rhs == null) {
this.setEquals(false);
return this;
}
if (lhs.length != rhs.length) {
isEquals = false;
return this;
}
for (int i = 0; i < lhs.length && isEquals; ++i) {
appendComparable(lhs[i], rhs[i]);
}
return this;
}
{code}
was:
As explained by LANG-393 and LANG-467, {{EqualsBuilder}} fails to provide a
proper way to handle {{BigDecimal}} since {{BigDecimal}} takes the scale into
account when using {{equals()}} but not with {{compareTo()}}.
Would it be possible to add a method *{{appendComparable()}}* in
{{EqualsBuilder}} to manages {{Comparable}} objects when we want to build
equality on {{compareTo()}} and not {{equals()}}?
Making clear that {{EqualsBuilder}} is not compliant with {{HashCodeBuilder}}
when using this method.
For example:
{code:borderStyle=solid}
return new EqualsBuilder()
.append(this.name, other.name)
.appendComparable(this.amount, other.amount)
.isEqual();
{code}
with:
{code:title=EqualsBuilder.java|borderStyle=solid}
public EqualsBuilder appendComparable(Comparable lhs, Comparable rhs) {
int c = new CompareToBuilder()
.append(lhs, rhs) // manages null
.toComparison();
return append(c, 0);
}
{code}
> Manages Comparable in EqualsBuilder
> -----------------------------------
>
> Key: LANG-1113
> URL: https://issues.apache.org/jira/browse/LANG-1113
> Project: Commons Lang
> Issue Type: New Feature
> Components: lang.builder.*
> Reporter: Simon Meyffret
> Priority: Trivial
> Labels: BigDecimal, EqualsBuilder
> Fix For: Discussion
>
>
> As explained by LANG-393 and LANG-467, {{EqualsBuilder}} fails to provide a
> proper way to handle {{BigDecimal}} since {{BigDecimal}} takes the scale into
> account when using {{equals()}} but not with {{compareTo()}}.
> Would it be possible to add a method *{{appendComparable()}}* in
> {{EqualsBuilder}} to manages {{Comparable}} objects when we want to build
> equality on {{compareTo()}} and not {{equals()}}?
> Making clear that {{EqualsBuilder}} is not compliant with {{HashCodeBuilder}}
> when using this method.
> For example:
> {code:borderStyle=solid}
> return new EqualsBuilder()
> .append(this.name, other.name)
> .appendComparable(this.amount, other.amount)
> .isEqual();
> {code}
> with:
> {code:title=EqualsBuilder.java|borderStyle=solid}
> /**
> * <p>Test if two <code>Comparable</code>s are equal using their
> * <code>compareTo</code> method.</p>
> * <p>This may break the <code>equals</code>/<code>hashcode</code>
> contract but
> * it is useful in some situation, specially with {@link
> java.math.BigDecimal}.</p>
> *
> * @param lhs the left hand comparable
> * @param rhs the right hand comparable
> * @return EqualsBuilder - used to chain calls.
> */
> public <T extends Comparable<? super T>> EqualsBuilder
> appendComparable(T lhs, T rhs) {
> if (isEquals == false) {
> return this;
> }
> if (lhs == rhs) {
> return this;
> }
> if (lhs == null || rhs == null) {
> isEquals = false;
> return this;
> } else if (lhs.compareTo(rhs) != 0) {
> isEquals = false;
> return this;
> }
> return this;
> }
>
> /**
> * <p>Performs a deep comparison of two <code>Comparable</code>
> arrays.</p>
> *
> * @param lhs the left hand <code>Comparable[]</code>
> * @param rhs the right hand <code>Comparable[]</code>
> * @return EqualsBuilder - used to chain calls.
> * @see #appendComparable(Comparable, Comparable)
> */
> public <T extends Comparable<? super T>> EqualsBuilder
> appendComparable(T[] lhs, T[] rhs) {
> if (isEquals == false) {
> return this;
> }
> if (lhs == rhs) {
> return this;
> }
> if (lhs == null || rhs == null) {
> this.setEquals(false);
> return this;
> }
> if (lhs.length != rhs.length) {
> isEquals = false;
> return this;
> }
> for (int i = 0; i < lhs.length && isEquals; ++i) {
> appendComparable(lhs[i], rhs[i]);
> }
> return this;
> }
> {code}
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