Jersey REST Server: instantiating resource classes

Question

A tutorial on the Jersey REST server [1] says of the Jersey servlet:

This servlet analyzes the incoming HTTP request and selects the correct class and

Answer 1

Jersey will establish a new instance of each class per request unless you annotate the class with @Singleton.

See: https://jersey.java.net/documentation/latest/jaxrs-resources.html#d0e2331

Answer 2

Actually according to this post default annotation type is change from singleton to per-request. Which means before one instance is used for every request but now create new class object for per-request. If you postwant to change it you can use resourceFactory annotation.

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ResourceFactory(SingletonProvider.class)
public @interface Singleton {}

Also you can check this link for com.sun.jersey.spi.resource JavaDoc