Package (GNU Classpath 0.94-pre Documentation)

Everything you ever wanted to know about a package. This class makes it possible to attach specification and implementation information to a package as explained in the Package Versioning Specification section of the Product Versioning Specification. It also allows packages to be sealed with respect to the originating URL.

The most useful method is the isCompatibleWith() method that compares a desired version of a specification with the version of the specification as implemented by a package. A package is considered compatible with another version if the version of the specification is equal or higher then the requested version. Version numbers are represented as strings of positive numbers separated by dots (e.g. "1.2.0"). The first number is called the major number, the second the minor, the third the micro, etc. A version is considered higher then another version if it has a bigger major number then the another version or when the major numbers of the versions are equal if it has a bigger minor number then the other version, etc. (If a version has no minor, micro, etc numbers then they are considered the be 0.)

Since: 1.2

See Also: ClassLoader

UNKNOWN: updated to 1.5

Method Summary
<A extends Annotation> A	getAnnotation(Class<A> annotationClass) Returns this package's annotation for the specified annotation type, or `null` if no such annotation exists.
Annotation[]	getAnnotations() Returns all annotations associated with this package.
Annotation[]	getDeclaredAnnotations() Returns all annotations directly defined by this package.
String	getImplementationTitle() Returns the name of the implementation, or null if unknown.
String	getImplementationVendor() Returns the vendor that wrote this implementation, or null if unknown.
String	getImplementationVersion() Returns the version of this implementation, or null if unknown.
String	getName() Returns the Package name in dot-notation.
static Package	getPackage(String name) Returns the named package if it is known by the callers class loader.
static Package[]	getPackages() Returns all the packages that are known to the callers class loader.
String	getSpecificationTitle() Returns the name of the specification, or null if unknown.
String	getSpecificationVendor() Returns the name of the specification designer, or null if unknown.
String	getSpecificationVersion() Returns the version of the specification, or null if unknown.
int	hashCode() Returns the hashCode of the name of this package.
boolean	isAnnotationPresent(Class<? extends Annotation> annotationClass) Returns true if an annotation for the specified type is associated with this package.
boolean	isCompatibleWith(String version) Checks if the version of the specification is higher or at least as high as the desired version.
boolean	isSealed() Returns true if this Package is sealed.
boolean	isSealed(URL url) Returns true if this Package is sealed and the origin of the classes is the given URL.
String	toString() Returns a string representation of this package.

Method Detail

getAnnotation

Returns this package's annotation for the specified annotation type, or null if no such annotation exists.

Parameters: annotationClass the type of annotation to look for.

Returns: this package's annotation for the specified type, or null if no such annotation exists.

Since: 1.5

getAnnotations

Returns all annotations associated with this package. If there are no annotations associated with this package, then a zero-length array will be returned. The returned array may be modified by the client code, but this will have no effect on the annotation content of this package, and hence no effect on the return value of this method for future callers.

Returns: this package' annotations.

Since: 1.5

getDeclaredAnnotations

Returns all annotations directly defined by this package. If there are no annotations associated with this package, then a zero-length array will be returned. The returned array may be modified by the client code, but this will have no effect on the annotation content of this package, and hence no effect on the return value of this method for future callers.

Returns: the annotations directly defined by this package.

Since: 1.5

getImplementationTitle

getImplementationVendor

getImplementationVersion

getName

getPackage

Returns the named package if it is known by the callers class loader. It may return null if the package is unknown, when there is no information on that particular package available or when the callers classloader is null.

Parameters: name the name of the desired package

Returns: the package by that name in the current ClassLoader

getPackages

getSpecificationTitle

getSpecificationVendor

getSpecificationVersion

hashCode

isAnnotationPresent

Returns true if an annotation for the specified type is associated with this package. This is primarily a short-hand for using marker annotations.

Parameters: annotationClass the type of annotation to look for.

Returns: true if an annotation exists for the specified type.

Since: 1.5

isCompatibleWith

Checks if the version of the specification is higher or at least as high as the desired version. Comparison is done by sequentially comparing dotted decimal numbers from the parameter and from getSpecificationVersion.

Parameters: version the (minimal) desired version of the specification

Returns: true if the version is compatible, false otherwise

Throws: NumberFormatException if either version string is invalid NullPointerException if either version string is null

isSealed

Returns true if this Package is sealed and the origin of the classes is the given URL.

Parameters: url the URL to test

Returns: true if the package is sealed by this URL

Throws: NullPointerException if url is null

toString

Returns a string representation of this package. It is specified to be

"package " + getName() + (getSpecificationTitle() == null
 ? "" : ", " + getSpecificationTitle()) + (getSpecificationVersion()
 == null ? "" : ", version " + getSpecificationVersion())

Returns: the string representation of the package

Class Package