sql logging for jsf application in netbeans

To enable SQL logging to the netbeans console for a JSF application running in Payara with EclipseLink, add the following properties to the persistence.xml file: 

<property name="eclipselink.logging.level" value="FINE"/>
<property name="eclipselink.logging.logger" value="DefaultLogger"/>

More information here and here.

On a related note, logging can also be enabled directly in mysql, if that's the underlying database.  Here are some notes about doing that:

log in to mysql as root:

-> use mysql; 

-> SET global log_output = 'table'; 

-> SET GLOBAL general_log = 1;

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then you can see the logged statements using:

select * from general_log;

or count the number of sql statements:

select count(*) from general_log; 

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and clean it up with:

truncate general_log; 

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java method reference

I can never remember the syntax for passing a method reference in Java, so I'm pasting a note about it here.  Here is a decent link explaining the idea.

Here is a method that accepts a method reference as a parameter, and calls that method in its body:

protected ItemDomainEntity findByPath_(String path, Function<ItemDomainEntity, ItemDomainEntity> parentGetterMethod) {

    <snip>
    ItemDomainEntity candidateParent = parentGetterMethod.apply(candidateItem);
    <snip>

}

And then an example of calling that method:

findByPath_(path, ItemDomainMachineDesign::getParentMachineDesign);