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https://issues.apache.org/jira/browse/LANG-985?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16361513#comment-16361513
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Osman Shoukry commented on LANG-985:
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If you use OpenPojo's toString it won't cause an issue while trying to call
"hashCode" which is the default implementation for toString on Object as
OpenPojo's toString doesn't call hashCode.
> ToStringBuilder reliably handle OpenPojo @BusinessKey annotated instances
> -------------------------------------------------------------------------
>
> Key: LANG-985
> URL: https://issues.apache.org/jira/browse/LANG-985
> Project: Commons Lang
> Issue Type: Wish
> Components: lang.builder.*
> Reporter: David Green
> Priority: Minor
> Labels: features
> Fix For: Discussion
>
>
> We use Google's OpenPojo library, annotating DTOs and persistence entities
> with @BusinessKey in order to remove boilerplate hashcode() and equals().
> I recently started noticing toString() was throwing exceptions when I didn't
> populate @BusinessKey annotated field(s) as I was using the Null Object
> Pattern. A workaround was to populate dummy values but there's a risk this
> could be considered a real value further down the line, so looked for an
> alternative solution and came up with the following extending
> StandardToStringStyle:-
> {code}
> import org.apache.commons.lang3.builder.StandardToStringStyle;
> import org.apache.commons.lang3.builder.ToStringStyle;
> public class CustomToStringStyle extends StandardToStringStyle {
> public static final ToStringStyle OPENPOJO_SAFE_STYLE =
> createOpenPojoSafeStyle();
> /**
> * Works better with {@link com.openpojo.business.annotation.BusinessKey}
> annotated OpenPojo classes.
> *
> * This instance does not call {@link ToStringStyle}.register(...)
> * which can throw a {@link
> com.openpojo.business.exception.BusinessException}
> * if the key hasn't been populated, for example if you used the Null
> Object Pattern.
> */
> private static ToStringStyle createOpenPojoSafeStyle() {
> final StandardToStringStyle style = new StandardToStringStyle();
> style.setUseClassName(false);
> style.setUseIdentityHashCode(false);
> return style;
> }
> }
> {code}
> Used as follows:
> {code}
> @Override
> public String toString() {
> return ToStringBuilder.reflectionToString(this,
> CustomToStringStyle.OPENPOJO_SAFE_STYLE);
> }
> {code}
> I realise this doesn't handle recursion in fields because it skips over
> ToStringStyle.register(..) but this suffices for our use case right now -
> perhaps an alternative implementation overriding register() that uses a List
> (with documented performance penalty) could be added.
> Is there anything already in Commons that could do this? If not we would like
> this to be considered for inclusion in commons lang (happy to help out with
> development), potentially with implementation improvements by those who know
> the code base better.
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