[WEB][42108] Best practice JPA repositories use

[JulienBertrand]

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Best practice JPA repositories use

Platform

OS	OS version	Langage
{Windows}	{}	{JAVA}

Main caracteristics

ID	Title	Category	Sub-category
CRJVM007-42108	Use Pageable on search methods of JPA	{Spring}	{JPA}

Severity / Remediation Cost

• Case 1:

Severity	Remediation Cost
Major	Major

Rule short description

• Case 1: Use Pageable on search methods of JPA repositories to avoid unused data retrieval

Rule complete description

Text

In many cases we only need to retrieve or display a subset of data and not all the data. To avoid unneeded data retrieval, it's better to make paginated queries to the database. Spring data has a Pageable feature implement by default by the JpaRepository which extends the PagingAndSortingRepository. All calls to search methods should ase a Pageable argument to specify the size and the number of the current page, this must be done on find* methods on a JPA repository.

JAVA Example

// Uncompliant code:

List<User> users = userRepository.findByFirstName(firstname);

// Compliant code:

Page<User> users = userRepository.findByFirstName(firstname, pageable);

Implementation principle

• 1- detect calls to findBy methods
• 2- check that it uses pagination
• 3- Otherwise, report the line in sonar

[jhertout]

Interesting but difficult to be sure that the rule is energy efficient (no documentation or something else to justify). May be a rule to measure in the next hackaton.

[dedece35]

ok with you @jhertout