Java Package Class



Introduction

The Java Package class contain version information about the implementation and specification of a Java package

Class Declaration

Following is the declaration for java.lang.Package class −

public class Package
   extends Object
      implements AnnotatedElement

Class methods

Sr.No. Method & Description
1 <A extends Annotation> A getAnnotation(Class<A> annotationClass)

This method returns this element's annotation for the specified type if such an annotation is present, else null.

2 Annotation[] getAnnotations()

This method returns all annotations present on this element.

3 Annotation[] getDeclaredAnnotations()

This method returns all annotations that are directly present on this element.

4 String getImplementationTitle()

This method return the title of this package.

5 String getImplementationVendor()

This method returns the name of the organization, vendor or company that provided this implementation.

6 String getImplementationVersion()

This method return the version of this implementation.

7 String getName()

This method return the name of this package.

8 static Package getPackage(String name)

This method find a package by name in the callers ClassLoader instance.

9 static Package[] getPackages()

This method get all the packages currently known for the caller's ClassLoader instance.

10 String getSpecificationTitle()

This method return the title of the specification that this package implements.

11 String getSpecificationVendor()

This method return the name of the organization, vendor, or company that owns and maintains the specification of the classes that implement this package.

12 String getSpecificationVersion()

This method returns the version number of the specification that this package implements.

13 int hashCode()

This method return the hash code computed from the package name.

14 boolean isAnnotationPresent(Class<? extends Annotation> annotationClass)

This method returns true if an annotation for the specified type is present on this element, else false.

15 boolean isCompatibleWith(String desired)

This method compare this package's specification version with a desired version.

16 boolean isSealed()

This method returns true if this package is sealed.

17 boolean isSealed(URL url)

This method returns true if this package is sealed with respect to the specified code source url.

18 String toString()

This method returns the string representation of this Package.

Methods inherited

This class inherits methods from the following classes −

  • java.lang.Object

Checking a Package being Sealed Example

The following example shows the usage of lang.Object.isSealed() method. In this program, we've checked the java.lang package being sealed or not using isSealed() method and result is printed as false.

package com.tutorialspoint;

public class PackageDemo {

   public static void main(String[] args) {

      // get the java lang package
      Package pack = Package.getPackage("java.lang");

      // check if this package is sealed
      System.out.println("" + pack.isSealed());
   }
}

Let us compile and run the above program, this will produce the following result −

false
Advertisements