spec/src/main/asciidoc/spec.adoc

== Introduction

With the addition of JSR 175 (A Metadata
Facility for the JavaTM Programming Language) in the Java platform we
envision that various technologies will use annotations to enable a
declarative style of programming. It would be unfortunate if these
technologies each independently defined their own annotations for common
concepts. It would be valuable to have consistency within the Jakarta EE
and Java SE component technologies, but it will also be valuable to
allow consistency between Jakarta EE and Java SE.

It is the intention of this specification to
define a small set of common annotations that will be available for use
within other specifications. It is hoped that this will help to avoid
unnecessary redundancy or duplication between annotations defined in
different Jakarta EE specifications. This would allow us to have
the common annotations all in one place and let the technologies refer
to this specification rather than have them specified in multiple
specifications. This way all technologies can use the same version of
the annotations and there will be consistency in the annotations used
across the platforms.

=== Goals

Define annotations for use in Jakarta EE: This
spec will define annotations for use within component technologies in
Jakarta EE as well as the platform as a whole.

=== Non-Goals

Support for Java versions prior to J2SE 5.0

Annotations were introduced in J2SE 5.0. It
is not possible to do annotation processing in versions prior to J2SE
5.0. It is not a goal of this specification to define a way of doing
annotation processing of any kind for versions prior to J2SE 5.0.

=== Compatibility

The annotations defined in this specification
may be included individually as needed in products that make use of
them. Other Java specifications will require support for subsets of
these annotations. Products that support these Java specifications must
include the required annotations.

=== Conventions

The keywords ‘MUST’, ‘MUST NOT’, ‘REQUIRED’,
‘SHALL’, ‘SHALL NOT’, ‘SHOULD’, ‘SHOULD NOT’, ‘RECOMMENDED’, ‘MAY’ AND
‘OPTIONAL’ in this document are to be interpreted as described in RFC
2119.

Java code is formatted as shown below:

[source,java]
----
package com.wombat.hello;

public class Hello {
    public static void main(String[] args) {
        System.out.println("Hello world");
    }
}
----

=== Expert Group Members

The following expert group members
participated in JSR 250:

- Cedric Beust (individual)
- Bill Burke (JBoss)
- Wayne Carr (Intel)
- Robert Clevenger (Oracle)
- Evan Ireland (Sybase)
- Woo Jin Kim (Tmax Soft)
- Gavin King (JBoss)
- Rajiv Mordani (Oracle Corporation, Specification lead)
- Ted Neward (individual)
- Anurag Parashar (Pramati technologies)
- Michael Santos (individual)
- Hani Suleiman (Ironflare AB)
- Seth White (BEA)

=== Acknowledgements

In addition to the expert group listed above,
Linda DeMichiel, Ron Monzillo, Lance Andersen and Bill Shannon all of
whom work at Oracle Corporation have provided input to this
specification.

== Annotations

This chapter describes the standard
annotations, some guidelines for annotation inheritance and the usage of
these annotations where possible.

=== General Guidelines for Inheritance of Annotations

The interplay of annotations and inheritance
in the Java language is potentially a source of complexity for
developers. Developers will rely on some implicit assumptions when
figuring out how annotations compose with other language features. At
the same time, annotation semantics are defined by individual
specifications, hence the potential for inconsistencies to arise. For
instance, consider the following example:

[source,java]
----
public class Base {
    @TransactionAttribute(REQUIRES_NEW)
    public void foo {...}
}

@Stateless
public class Derived extends Base {
    @TransactionAttribute(NEVER)
    public void foo {...}
}
----

In keeping with the concept of method
overriding, most developers will assume that in the _Derived_ class, the
effective _TransactionAttribute_ annotation for method _foo_ is
_TransactionAttribute(NEVER)_ . On the other hand, it might have been
possible for the specification governing the semantics of the
_TransactionAttribute_ annotations type to require that the effective
_TransactionAttribute_ to be the most restrictive one in the whole
inheritance tree, that is, in the example above
_TransactionAttribute(REQUIRES_NEW)_ . A motivation for these semantics
might have been that the _foo_ method in the _Derived_ class may call
_super.foo()_ , resulting in the execution of some code that needs a
transaction to be in place. Such a choice on the part of the
specification for _TransactionAttribute_ would have contradicted a
developer’s intuition on how method overriding works.

In order to keep the resulting complexity in
control, below are some guidelines recommended for how annotations
defined in the different specifications should interact with
inheritance:

. Class-level annotations only affect the
class they annotate and its members, that is, its methods and fields.
They never affect a member declared by a superclass, even if it is not
hidden or overridden by the class in question.

. In addition to affecting the annotated class,
class-level annotations may act as a shorthand for member-level
annotations. If a member carries a specific member-level annotation, any
annotations of the same type implied by a class-level annotation are
ignored. In other words, explicit member-level annotations have priority
over member-level annotations implied by a class-level annotation. For
example, a _TransactionAttribute(REQUIRED)_ annotation on a class
implies that all the public methods in the class that it is applied on
are annotated with _TransactionAttribute(REQUIRED)_ . However if there
is a _TransactionAttribute(NEVER)_ annotation on a particular method,
then the _TransactionAttribute(NEVER)_ applies for that particular
method and not _TransactionAttribute(REQUIRED)_ .

. The interfaces implemented by a class never
contribute annotations to the class itself or any of its members.

. Members inherited from a superclass and which
are not hidden or overridden maintain the annotations they had in the
class that declared them, including member-level annotations implied by
class-level ones.

. Member-level annotations on a hidden or overridden member are always ignored.

This set of guidelines guarantees that the
effects of an annotation are local to the class on, or inside, which it
appears. In order to find the effective annotation for a class member, a
developer has to track down its last non-hidden and non-overridden
declaration and examine it. If the sought-for annotation is not found
there, then (s)he will have to examine the enclosing class declaration.
If even this step fails to provide an annotation, no other source file
will be consulted.

Below are some examples that explain how the
guidelines defined above will be applied to the _TransactionAttribute_
annotation.

[source,java]
----
@TransactionAttribute(REQUIRED)
class Base {
    @TransactionAttribute(NEVER)
    public void foo() {...}

    public void bar() {...}
}

@Stateless
class ABean extends Base {
    public void foo() {...}
}

@Stateless
public class BBean extends Base {
    @TransactionAttribute(REQUIRES_NEW)
    public void foo() {...}
}

@Stateless
@TransactionAttribute(REQUIRES_NEW)
public class CBean extends Base {
    public void foo() {...}
    public void bar() {...}
}

@Stateless
@TransactionAttribute(REQUIRES_NEW)
public class DBean extends Base {
    public void bar() {...}
}

@Stateless
@TransactionAttribute(REQUIRES_NEW)
public class EBean extends Base {
    // ...
}
----

The table below shows the effective
_TransactionAttribute_ annotation in each of the cases above by applying
the guidelines specified for annotations and inheritance:

|===
|Methods in derived classes |Effective TransactionAttribute value
|foo() in ABean
|TransactionAttribute(REQUIRED). (Default TransactionAttribute as defined by the Jakarta Enterprise Beans specification).
|bar() in ABean
|TransactionAttribute(REQUIRED)
|foo() in BBean
|TransactionAttribute(REQUIRES_NEW)
|bar() in BBean
|TransactionAttribute(REQUIRED)
|foo() in CBean
|TransactionAttribute(REQUIRES_NEW)
|bar() in CBean
|TransactionAttribute(REQUIRES_NEW)
|foo() in DBean
|TransactionAttribute(NEVER) (from Base class)
|bar() in DBean
|TransactionAttribute(REQUIRES_NEW)
|foo() in EBean
|TransactionAttribute(NEVER) (from Base class)
|bar() in EBean
|TransactionAttribute(REQUIRED) (from Base class)
|===

For more details about the _TransactionAttribute_ annotation, see the _Jakarta Enterprise Beans Core Contracts_
specification.

All annotations defined in this specification
follow the guidelines defined above unless explicitly stated otherwise.

=== jakarta.annotation.Generated

The _Generated_ annotation is used to mark
source code that has been generated. It can be specified on a class,
method, or field. It can also be used to differentiate user-written code
from generated code in a single file.

The _value_ element MUST have the name of the
code generator. The recommended convention is to use the fully qualified
name of the code generator. For example: _com.company.package.classname_
.

The _date_ element is used to indicate the
date the source was generated. The _date_ element MUST follow the ISO
8601 standard. For example the _date_ element could have the following
value:

    2001-07-04T12:08:56.235-0700

which represents 2001-07-04 12:08:56 local
time in the U.S. Pacific time zone.

The _comments_ element is a place holder for
any comments that the code generator may want to include in the
generated code.

[source,java]
----
package jakarta.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({ANNOTATION_TYPE, CONSTRUCTOR, FIELD, LOCAL_VARIABLE, METHOD, PACKAGE, PARAMETER, TYPE})
@Retention(SOURCE)
public @interface Generated {
    String[] value();
    String date() default "";
    String comments() default "";
}
----

|===
|Element |Description |Default
|value |Name of the code generator |
|date |Date source was generated. MUST follow ISO 8601 standard |""
|comments |placeholder for comments that the generator may want to include in the generated code |""
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@Generated("com.sun.xml.rpc.AProcessor")
public interface StockQuoteService extends java.rmi.Remote {
    this.context = context;
}
----

=== jakarta.annotation.Resource

The _Resource_ annotation is used to declare
a reference to a resource. It can be specified on a class, method, or
field. When the annotation is applied on a field or method, the
container will inject an instance of the requested resource into the
application when the application is initialized. If the annotation is
applied to a class, the annotation declares a resource that the
application will look up at runtime. Even though this annotation is not
marked _Inherited_ , all superclasses MUST be examined to discover all
uses of this annotation. All such annotation instances specify resources
that are needed by the application. Note that this annotation may appear
on private fields and methods of superclasses. Injection of the declared
resources needs to happen in these cases as well, even if a method with
such an annotation is overridden by a subclass.

The _name_ element is the JNDI name of the
resource. When the _Resource_ annotation is applied on a field, the
default value of the _name_ element is the field name qualified by the
class name. When applied on a method, the default is the JavaBeans
property name corresponding to the method qualified by the class name.
When applied on a class, there is no default and the name MUST be
specified.

The _type_ element defines the Java type of
the resource. When the _Resource_ annotation is applied on a field, the
default value of the _type_ element is the type of the field. When
applied on a method, the default is the type of the JavaBeans property.
When applied on a class, there is no default and the type MUST be
specified. When used, the type MUST be assignment compatible.

The _authenticationType_ element is used to
indicate the authentication type to use for the resource. It can take
one of two values defined as an _Enum_ : _CONTAINER_ or _APPLICATION_ .
This element may be specified for resources representing a connection
factory of any supported type and MUST NOT be specified for resources of
other types.

The _shareable_ element is used to indicate
whether a resource can be shared between this component and other
components. This element may be specified for resources representing a
connection factory of any supported type or ORB object instances and
MUST NOT be specified for resources of other types.

The _mappedName_ element is a
product-specific name that this resource should be mapped to. The
_mappedName_ element provides for mapping the resource reference
specified by the _Resource_ annotation to the name of a resource known
to the application server. The mapped name could be of any form.
Application servers are not required to support any particular form or
type of mapped name, nor the ability to use mapped names. The mapped
name is product dependent and often installation dependent. No use of
mapped name is portable.

The _description_ element is the description
of the resource. The description is expected to be in the default
language of the system on which the application is deployed. The
description can be presented to help in choosing the correct resource.

The _lookup_ element specifies the JNDI name
of a resource that the resource being defined will be bound to. The type
of the referenced resource must be compatible with that of the resource
being defined.

[source,java]
----
package jakarta.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({TYPE, METHOD, FIELD})
@Retention(RUNTIME)
@Repeatable(Resources.class)
public @interface Resource {
    public enum AuthenticationType {
        CONTAINER,
        APPLICATION
    }

    String name() default "";

    Class<?> type() default Object.class;

    AuthenticationType authenticationType() default AuthenticationType.CONTAINER;

    boolean shareable() default true;

    String mappedName() default "";

    String description() default "";

    String lookup() default "";
}
----


|===
|Element |Description |Default
|name |The JNDI name of the resource |""
|type |The Java type of the resource |Object.class
|authenticationType |The authentication type to use for the resource |CONTAINER
|shareable |Indicates whether the resource can be shared. |true
|mappedName |A product-specific name that the resource should map to. |""
|description |Description of the resource. |""
|lookup |the JNDI name of a resource that the resource being defined will be bound to |""
|===

==== Field based injection

To access a resource a developer declares a
field and annotates it as being a resource reference. If the name and
type elements are missing from the annotation they will be inferred by
looking at the field declaration itself. It is an error if the type
specified by the _Resource_ annotation and the type of the field are
incompatible.

For example:

[source,java]
----
@Resource
private DataSource myDB;
----

In the example above the effective name is
_com.example.class/myDB_ and the effective type is
_javax.sql.DataSource.class_ .

[source,java]
----
@Resource(name="customerDB")
private DataSource myDB;
----

In the example above the name is _customerDB_
and the effective type is _javax.sql.DataSource.class_ .

==== Setter based injection

To access a resource a developer declares a
setter method and annotates it as being a resource reference. The name
and type of resource may be inferred by inspecting the method
declaration if necessary. The name of the resource, if not declared, is
the name of the JavaBeans property as determined from the name of the
setter method. The setter method MUST follow the standard JavaBeans
convention—the name starts with “ _set_ ”; the return type is _void_ ;
and there is only one parameter. Additionally, the type of the parameter
MUST be compatible with the _type_ element of the _Resource_ annotation,
if specified.

For example:

[source,java]
----
@Resource
private void setMyDB(DataSource ds) {
    myDB = ds;
}

private DataSource myDB;
----

In the example above the effective name is
_com.example.class/myDB_ and the type is _javax.sql.DataSource.class_ .

[source,java]
----
@Resource(name="customerDB")
private void setMyDB(DataSource ds) {
    myDB = ds;
}

private DataSource myDB;
----

In the example above the name is _customerDB_
and the type is _javax.sql.DataSource.class_ .

The table below shows the mapping from Java
type to the equivalent resource type in the Jakarta EE 9 (and later)
deployment descriptors:

[options="header"]
|===
|Java Type |Equivalent Resource type
|java.lang.String |env-entry
|java.lang.Character |env-entry
|java.lang.Integer |env-entry
|java.lang.Boolean |env-entry
|java.lang.Double |env-entry
|java.lang.Byte |env-entry
|java.lang.Short |env-entry
|java.lang.Long |env-entry
|java.lang.Float |env-entry
|jakarta.xml.ws.Service |service-ref
|jakarta.jws.WebService |service-ref
|javax.sql.DataSource |resource-ref
|jakarta.jms.ConnectionFactory |resource-ref
|jakarta.jms.QueueConnectionFactory |resource-ref
|jakarta.jms.TopicConnectionFactory |resource-ref
|jakarta.mail.Session |resource-ref
|java.net.URL |resource-ref
|jakarta.resource.cci.ConnectionFactory |resource-ref
|any other connection factory defined by a resource adapter |resource-ref
|jakarta.jms.Queue |message-destination-ref
|jakarta.jms.Topic |message-destination-ref
|jakarta.resource.cci.InteractionSpec |resource-env-ref
|jakarta.transaction.UserTransaction |resource-env-ref
|Everything else |resource-env-ref
|===

=== jakarta.annotation.Resources

The _Resource_ annotation is used to declare
a reference to a resource. The _Resources_ annotation acts as a
container for multiple resource declarations.

[source,java]
----
package jakarta.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({TYPE})
@Retention(RUNTIME)
public @interface Resources {
    Resource[] value;
}
----

|===
|Element |Description |Default
|value |Container for defining multiple resources. |
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@Resources ({
    @Resource(name="myDB", type=javax.sql.DataSource),
    @Resource(name="myMQ", type=jakarta.jms.ConnectionFactory)
})

public class CalculatorBean {
    // ...
}
----

=== jakarta.annotation.PostConstruct

The _PostConstruct_ annotation is used on a
method that needs to be executed after dependency injection is done to
perform any initialization. This method MUST be invoked before the class
is put into service. This annotation MUST be supported on all classes
that support dependency injection. The method annotated with
_PostConstruct_ MUST be invoked even if the class does not request any
resources to be injected. Only one method in a given class can be
annotated with this annotation. The method on which the _PostConstruct_
annotation is applied MUST fulfill all of the following requirements,
except in cases where these requirements have been relaxed by another
specification. See in particular the _Jakarta Interceptors_ specification.

- The method MUST NOT have any para meters.

- The return type of the method MUST be _void_ .

- The method MUST NOT throw a checked exception.

- The method on which _PostConstruct_ is
applied MAY be _public_ , _protected_ , package private or _private_ .

- The method MUST NOT be static except for the application client.

- In general, the method MUST NOT be final.
However, other specifications are permitted to relax this requirement on
a per-component basis.

- If the method throws an unchecked exception the class MUST NOT be put into service.

[source,java]
----
package jakarta.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target(METHOD)
@Retention(RUNTIME)
public @interface PostConstruct {

}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
@Resource
private void setMyDB(DataSource ds) {
    myDB = ds;
}

@PostConstruct
private void initialize() {
    // Initialize the connection object from the DataSource
    connection = myDB.getConnection();
}

private DataSource myDB;
private Connection connection;
----


=== jakarta.annotation.PreDestroy

The _PreDestroy_ annotation is used on a
method as a callback notification to signal that the instance is in the
process of being removed by the container. The method annotated with
_PreDestroy_ is typically used to release resources that the instance
has been holding. This annotation MUST be supported by all container
managed objects that support _PostConstruct_ except the application
client. The method on which the _PreDestroy_ annotation is applied MUST
fulfill all of the following requirements, except in cases where these
requirements have been relaxed by another specification. See in
particular the _Jakarta Interceptors_ specification.

- The method MUST NOT have any para meters.

- The return type of the method MUST be _void_ .

- The method MUST NOT throw a checked exception.

- The method on which _PreDestroy_ is applied
MAY be _public_ , _protected_ , package private or _private_ .

- The method MUST NOT be static.

- In general, the method MUST NOT be final.
However, other specifications are permitted to relax this requirement on
a per-component basis.

- If the method throws an unchecked exception it is ignored.

[source,java]
----
package jakarta.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target(METHOD)
@Retention(RUNTIME)
public @interface PreDestroy {

}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
@Resource
private void setMyDB(DataSource ds) {
    myDB = ds;
}

@PostConstruct
private void initialize() {
    // Initialize the connection object from the DataSource
    connection = myDB.getConnection();
}

@PreDestroy
private void cleanup() {
    // Close the connection to the DataSource.
    connection.close();
}

private DataSource myDB;
private Connection connection;
----

=== jakarta.annotation.Priority

The _Priority_ annotation can be applied to
any program elements to indicate in what order they should be used. The
effect of using the _Priority_ annotation in any particular instance is
defined by other specifications that define the use of a specific class.

For example, the _Jakarta Interceptors_ specification
defines the use of priorities on interceptors to control the order in
which interceptors are called.

Priority values should generally be
non-negative, with negative values reserved for special meanings such as
“undefined” or “not specified”. A specification that defines use of the
_Priority_ annotation may define the range of allowed priorities and any
priority values with special meaning.

[source,java]
----
package jakarta.annotation;

import java.lang.annotation.*;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Retention(RUNTIME)
@Documented
public @interface Priority {
     // The priority value.
     int value();
}
----

=== jakarta.annotation.Nonnull

The _Nonnull_ annotation is used to mark
elements that cannot be `null`.

This information can be used for validation by IDEs, static analysis tools, and runtime.

The annotation may be present on any target.
This specification defines behavior on following targets:

- Method -  return type will never be `null`
- Parameter - parameter must not be `null`
- Field - field cannot be `null` after construction of the object is completed

[source,java]
----
package jakarta.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Documented
@Retention(RUNTIME)
public @interface Nonnull {
}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
public interface StockQuoteService {
    @Nonnull
    BigDecimal quote(@Nonnull String marker);
}
----

=== jakarta.annotation.Nullable

The _Nullable_ annotation is used to mark
elements that may be `null`.

This information can be used for validation by IDEs, static analysis tools, and runtime.

The annotation may be present on any target.
This specification defines behavior on following targets:

- Method -  return type may be `null`
- Parameter - parameter may be `null`
- Field - field may be `null`

[source,java]
----
package jakarta.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Documented
@Retention(RUNTIME)
public @interface Nullable {
}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
public interface StockQuoteService {
    BigDecimal quote(String marker, @Nullable BigDecimal defaultValue);
}
----

=== jakarta.annotation.security.RunAs

The _RunAs_ annotation defines the security
role of the application during execution in a Jakarta EE container. It can
be specified on a class. This allows developers to execute an
application under a particular role. The role MUST map to the user /
group information in the container’s security realm. The _value_ element
in the annotation is the name of a security role.

[source,java]
----
package jakarta.annotation.security;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target(TYPE)
@Retention(RUNTIME)
public @interface RunAs {
    String value();
}
----

|===
|Element |Description |Default
|value |Security role of the application during execution in a Jakarta EE container |
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@RunAs("Admin")
public class Calculator {
    // ...
}
----

=== jakarta.annotation.security.RolesAllowed

The _RolesAllowed_ annotation specifies the
security roles permitted to access method(s) in an application. The
value element of the _RolesAllowed_ annotation is a list of security
role names.

The _RolesAllowed_ annotation can be
specified on a class or on method(s). Specifying it at a class level
means that it applies to all the methods in the class. Specifying it on
a method means that it is applicable to that method only. If applied at
both the class and method level, the method value overrides the class
value.

[source,java]
----
package jakarta.annotation.security;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({TYPE,METHOD})
@Retention(RUNTIME)
public @interface RolesAllowed {
    String[] value();
}
----

|===
|Element |Description |Default
|value |List of roles permitted to access methods in the application |
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@RolesAllowed("Users")
public class Calculator {
    @RolesAllowed("Administrator")
    public void setNewRate(int rate) {
        // ...
    }
}
----

=== jakarta.annotation.security.PermitAll

The _PermitAll_ annotation specifies that all
security roles are allowed to invoke the specified method(s), that is,
that the specified method(s) are “unchecked”. It can be specified on a
class or on methods. Specifying it on the class means that it applies to
all methods of the class. If specified at the method level, it only
affects that method.

[source,java]
----
package jakarta.annotation.security;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({TYPE,METHOD})
@Retention(RUNTIME)
public @interface PermitAll {

}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
import jakarta.annotation.security.*;

@RolesAllowed("Users")
public class Calculator {
    @RolesAllowed("Administrator")
    public void setNewRate(int rate) {
        // ...
    }

    @PermitAll
    public long convertCurrency(long amount) {
        // ...
    }
}
----

=== jakarta.annotation.security.DenyAll

The _DenyAll_ annotation specifies that no
security roles are allowed to invoke the specified method(s), that is,
that the method(s) are to be excluded from execution in the Jakarta EE
container.

[source,java]
----
package jakarta.annotation.security;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target({TYPE, METHOD})
@Retention(RUNTIME)
public @interface DenyAll {

}
----

The following example shows the usage of the annotation defined above:

[source,java]
----
import jakarta.annotation.security.*;

@RolesAllowed("Users")
public class Calculator {
    @RolesAllowed("Administrator")
    public void setNewRate(int rate) {
        // ...
    }

    @DenyAll
    public long convertCurrency(long amount) {
        // ...
    }
}
----

=== PermitAll, DenyAll and RolesAllowed interactions

The _PermitAll_ , _DenyAll_ and
_RolesAllowed_ annotations all define which security roles are allowed
to access the methods on which they are applied. This section describes
how these annotations interact and which usages of these annotations are
valid.

If the _PermitAll_ , _DenyAll_ and
_RolesAllowed_ annotations are applied on methods of a class, then the
method level annotations take precedence (at the corresponding methods)
over any class level annotations of type _PermitAll_ , _DenyAll_ and
_RolesAllowed_ .

=== jakarta.annotation.security.DeclareRoles

The _DeclareRoles_ annotation is used to
specify security roles used by the application. It can be specified on a
class. It typically would be used to define roles that could be tested
(i.e., by calling _isUserInRole_ ) from within the methods of the
annotated class. It could also be used to declare roles that are not
implicitly declared as the result of their use in a _RolesAllowed_
annotation on the class or a method of the class.

[source,java]
----
package jakarta.annotation.security;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

@Target(TYPE)
@Retention(RUNTIME)
public @interface DeclareRoles {
    String[] value();
}
----

|===
|Element |Description |Default
|value |List of security roles specified by the application |
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@DeclareRoles("BusinessAdmin")
public class Calculator {
    public void convertCurrency() {
        if (x.isUserInRole("BusinessAdmin")) {
            // ...
        }
    }

    // ...
}
----

=== jakarta.annotation.sql.DataSourceDefinition

The _DataSourceDefinition_ annotation is used
to define a container _DataSource_ to be registered with JNDI. The
_DataSource_ may be configured by setting the annotation elements for
commonly-used _DataSource_ properties. Additional standard and
vendor-specific properties may be specified using the _properties_
element. The data source will be registered under the name specified in
the _name_ element. It may be defined to be in any valid Jakarta EE
namespace, which will determine the accessibility of the data source
from other components. A JDBC driver implementation class of the
appropriate type, either _DataSource_ , _ConnectionPoolDataSource_ , or
_XADataSource_ , must be indicated by the _className_ element. The
driver class is not required to be available at deployment but must be
available at runtime prior to any attempt to access the _DataSource_ .

 _DataSource_ properties should not be
specified more than once. If the _url_ annotation element contains a
_DataSource_ property that was also specified using the corresponding
annotation element or was specified in the _properties_ annotation
element, the precedence order is undefined and implementation specific.

Vendors are not required to support
_properties_ that do not normally apply to a specific data source type.
For example, specifying the _transactional_ property to be _true_ but
supplying a value for _className_ that implements a data source class
other than _XADataSource_ may not be supported.

Vendor-specific properties may be combined
with or used to override standard data source properties defined using
this annotation.

_DataSource_ properties that are specified
and are not supported in a given configuration or cannot be mapped to a
vendor-specific configuration property may be ignored.

Although the annotation allows you to specify
a password, it is recommended not to embed passwords in production code.
The _password_ element in the annotation is provided as a convenience
for ease of development.

[source,java]
----
package jakarta.annotation.sql;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import java.lang.annotation.ElementType;
import java.lang.annotation.RetentionPolicy;

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Repeatable(DataSourceDefinitions.class)
public @interface DataSourceDefinition {
    String name();
    String className();
    String description() default "";
    String url() default "";
    String user() default "";
    String password() default "";
    String databaseName() default "";
    int portNumber() default -1;
    String serverName() default "localhost";
    int isolationLevel() default -1;
    boolean transactional() default true;
    int initialPoolSize() default -1;
    int maxPoolSize() default -1;
    int minPoolSize() default -1;
    int maxIdleTime() default -1;
    int maxStatements() default -1;
    String[] properties() default \{};
    int loginTimeout() default 0;
}
----

[width="100%",cols="34%,33%,33%",options="header",]
|===
|Element |Description |Default
| _name_ |JNDI name by which the data source will be registered |
| _className_ |DataSource implementation class name |
| _description_ |Description of the data source |""
| _url_ |A JDBC URL. If the url annotation element contains a DataSource property that was also specified using the corresponding annotation element, the precedence order is undefined and implementation specific. |""
| _user_ |User name for connection authentications |""
| _password_ |Password for connection authentications |""
| _databaseName_ |Name of a database on a server |""
| _portNumber_ |Port number where a server is listening for requests |""
| _serverName_ |Database server name |"localhost"
| _isolationLevel_ |Isolation level for connections. |-1 (vendor specific)
| _transactional_ |Indicates whether a connection is transactional or not |true
| _initialPoolSize_ |Number of connections that should be created when a connection pool is initialized |-1 (vendor specific)
| _maxPoolSize_ |Maximum number of connections that should be concurrently allocated for a connection pool |-1 (vendor specific)
| _minPoolSize_ |Minimum number of connections that should be allocated for a connection pool |-1 (vendor specific)
| _maxIdleTime_ |The number of seconds that a physical connection should remain unused in the pool before the connection is closed for a connection pool |-1 (vendor specific)
| _maxStatements_ |The total number of statements that a connection pool should keep open. A value of 0 indicates that the caching of statements is disabled for a connection pool |-1 (vendor specific)
| _properties_ |Used to specify vendor-specific properties and less commonly used _DataSource_ properties. If a _DataSource_ property is specified in the properties element and the annotation element for the property is also specified, the annotation element value takes precedence. |\{}
| _loginTimeout_ |The maximum time in seconds that this data source will wait while attempting to connect to a database. A value of 0 specifies that the timeout is the default system timeout if there is one, otherwise it specifies that there is no timeout |0
|===

Examples:

[source,java]
----
@DataSourceDefinition(
    name="java:global/MyApp/MyDataSource",
    className="com.foobar.MyDataSource",
    portNumber=6689,
    serverName="myserver.com",
    user="lance",
    password="secret")

----

Using a URL:

[source,java]
----
@DataSourceDefinition(
    name="java:global/MyApp/MyDataSource",
    className="org.apache.derby.jdbc.ClientDataSource",
    url="jdbc:derby://localhost:1527/myDB",
    user="lance",
    password="secret")
----

=== jakarta.annotation.sql.DataSourceDefinitions

The _DataSourceDefinition_ annotation is used
to declare a container _DataSource_ . The _DataSourceDefinitions_
annotation acts as a container for multiple data source declarations.

[source,java]
----
package jakarta.annotation.sql;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import java.lang.annotation.ElementType;
import java.lang.annotation.RetentionPolicy;

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface DataSourceDefinitions {
    DataSourceDefinition[] value ();
}
----

|===
|Element |Description |Default
|value |Container for defining multiple data sources. |
|===

The following example shows the usage of the annotation defined above:

[source,java]
----
@DataSourceDefinitions ({
    @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
        className="com.foobar.MyDataSource",
        portNumber=6689,
        serverName="myserver.com",
        user="lance",
        password="secret"),

    @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
        className="org.apache.derby.jdbc.ClientDataSource",
        url="jdbc:derby://localhost:1527/myDB",
        user="lance",
        password="secret")
})
public class CalculatorBean {
    // ...
}
----

== References

Java SE,
https://www.oracle.com/java/

JSR 175: A Metadata Facility for the Java
Programming Language. http://jcp.org/en/jsr/detail?id=175

Jakarta EE Platform (Jakarta EE),
https://jakarta.ee/specifications/platform/

Jakarta Enterprise Beans,
https://jakarta.ee/specifications/enterprise-beans/

Jakarta Interceptors,
https://jakarta.ee/specifications/interceptors/

RFC 2119.
http://www.faqs.org/rfcs/rfc2119.html