[Java][Team 2 millions] Use of Entity in Rest controller

[JulienPlanque]

Optimized API: Use of Entity in Rest controller

Platform

OS	OS version	Langage
-	-	Java

Main caracteristics

ID	Title	Category	Sub-category
???	Use of Entity in Rest controller	Environment	Optimized API

Severity / Remediation Cost

Severity	Remediation Cost
Minor	Minor

Rule short description

Using persistence Entity in the return of a Rest controler is not
energy efficient. This use induces a multiples unnecessary SQL calls, multiple unused fields serialization,
and thus unnecessary calculations by the CPU, RAM usage and network usage.

Rule complete description

Text

Using persistence Entity, class with @entity annotation of javax.persistence is not
energy efficient.
Prefer the usage of Data Transfert Object (DTO) which is more energy friendly. This reduces the amount of information returned so that it is more relevant and lighter.

<p>Using persistence Entity in the return of a Rest controler is not
energy efficient. This use induces a multiples unnecessary SQL calls, multiple unused fields serialization,
and thus unnecessary calculations by the CPU, RAM usage and network usage. </p>
<h2>Noncompliant</h2>
<pre>
	@RestController
    public class AvoidReturningSpringEntityInRestController {
        private final BookService bookService;

        public AvoidReturningSpringEntityInRestController(BookService bookstoreService) {
            this.bookService = bookstoreService;
        }

        @RequestMapping("books")
        public List<Book> findBooks() {
        return bookService.findAll();
        }
    }

    @Entity
    public class Books {
        // Attributes of books
    }
</pre>
<h2>Compliant Solution</h2>
<pre>
    @RestController
    public class AvoidReturningSpringEntityInRestController {
        private final BookService bookService;

        public AvoidReturningSpringEntityInRestController(BookService bookstoreService) {
            this.bookService = bookstoreService;
        }

        @RequestMapping("books")
        public List<BookDTO> findBooks() {
            return BookMapper.from(bookService.findAll());
        }
    }
</pre>

Implementation principle

• Inspect the all classes with @RestController annotation
• Inpect in all method the class in return, directly or in a collection
• If this class has @entity annotation of javax.persistence, report the line

[JulienPlanque]

Build by Teams 2 millions

[dedece35]

Hi @MP-Aubay, @JulienPlanque

sorry but with implementation is that situation, we can't accept this implementation because :

• no scientific paper to prove this rule
• no measures to prove it's a "green" rule

We keep this proposition to measure it when we will have a tool to measure it.
(check RULES.md )