-/* java.lang.Package - Everything you ever wanted to know about a package.
- Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+/* Package.java -- information about a package
+ Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of GNU Classpath.
* section of the
* <a href="http://java.sun.com/products/jdk/1.3/docs/guide/versioning/spec/VersioningSpecification.html">Product Versioning Specification</a>.
* It also allows packages to be sealed with respect to the originating URL.
- * <p>
- * The most useful method is the <code>isCompatibleWith()</code> method that
+ *
+ * <p>The most useful method is the <code>isCompatibleWith()</code> 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
* then the other version, etc. (If a version has no minor, micro, etc numbers
* then they are considered the be 0.)
*
+ * @author Mark Wielaard <mark@klomp.org>
+ * @see ClassLoader#definePackage(String, String, String, String, String,
+ * String, String, URL)
* @since 1.2
- * @author Mark Wielaard (mark@klomp.org)
+ * @status updated to 1.4
*/
public class Package
{
/** The name if the implementation */
final private String implTitle;
+
/** The vendor that wrote this implementation */
final private String implVendor;
+
/** The version of this implementation */
final private String implVersion;
/** The name of the specification */
final private String specTitle;
+
/** The name of the specification designer */
final private String specVendor;
+
/** The version of this specification */
final private String specVersion;
/** If sealed the origin of the package classes, otherwise null */
final private URL sealed;
- /**
- * A package local constructor for the Package class.
- * All parameters except the <code>name</code> of the package may be
- * <code>null</code>.
- * There are no public constructors defined for Package this is a package
+ /**
+ * A package local constructor for the Package class. All parameters except
+ * the <code>name</code> of the package may be <code>null</code>.
+ * There are no public constructors defined for Package; this is a package
* local constructor that is used by java.lang.Classloader.definePackage().
*
* @param name The name of the Package
throw new IllegalArgumentException("null Package name");
this.name = name;
-
this.implTitle = implTitle;
this.implVendor = implVendor;
this.implVersion = implVersion;
-
this.specTitle = specTitle;
this.specVendor = specVendor;
this.specVersion = specVersion;
-
this.sealed = sealed;
}
- /**
- * Returns the Package name.
+ /**
+ * Returns the Package name in dot-notation.
+ *
+ * @return the non-null package name
*/
public String getName()
{
return name;
}
- /**
- * Returns the name of the implementation or null if unknown.
+ /**
+ * Returns the name of the specification, or null if unknown.
+ *
+ * @return the specification title
*/
- public String getImplementationTitle()
+ public String getSpecificationTitle()
{
- return implTitle;
+ return specTitle;
}
- /**
- * Returns the vendor that wrote this implementation or null if unknown.
+ /**
+ * Returns the version of the specification, or null if unknown.
+ *
+ * @return the specification version
*/
- public String getImplementationVendor()
+ public String getSpecificationVersion()
{
- return implVendor;
+ return specVersion;
}
- /**
- * Returns the version of this implementation or null if unknown.
+ /**
+ * Returns the name of the specification designer, or null if unknown.
+ *
+ * @return the specification vendor
*/
- public String getImplementationVersion()
+ public String getSpecificationVendor()
{
- return implVersion;
+ return specVendor;
}
- /**
- * Returns the name of the specification or null if unknown.
+ /**
+ * Returns the name of the implementation, or null if unknown.
+ *
+ * @return the implementation title
*/
- public String getSpecificationTitle()
+ public String getImplementationTitle()
{
- return specTitle;
+ return implTitle;
}
- /**
- * Returns the name of the specification designer or null if unknown.
+ /**
+ * Returns the version of this implementation, or null if unknown.
+ *
+ * @return the implementation version
*/
- public String getSpecificationVendor()
+ public String getImplementationVersion()
{
- return specVendor;
+ return implVersion;
}
- /**
- * Returns the version of the specification or null if unknown.
+ /**
+ * Returns the vendor that wrote this implementation, or null if unknown.
+ *
+ * @return the implementation vendor
*/
- public String getSpecificationVersion()
+ public String getImplementationVendor()
{
- return specVersion;
+ return implVendor;
}
- /**
+ /**
* Returns true if this Package is sealed.
+ *
+ * @return true if the package is sealed
*/
public boolean isSealed()
{
- return (sealed != null);
+ return sealed != null;
}
- /**
+ /**
* Returns true if this Package is sealed and the origin of the classes is
* the given URL.
- *
- * @param url
+ *
+ * @param url the URL to test
+ * @return true if the package is sealed by this URL
+ * @throws NullPointerException if url is null
*/
public boolean isSealed(URL url)
{
/**
* Checks if the version of the specification is higher or at least as high
- * as the desired version.
+ * as the desired version. Comparison is done by sequentially comparing
+ * dotted decimal numbers from the parameter and from
+ * <code>getSpecificationVersion</code>.
+ *
* @param version the (minimal) desired version of the specification
- * @exception NumberFormatException when either version or the
- * specification version is not a correctly formatted version number
- * @exception NullPointerException if the supplied version or the
- * Package specification version is null.
+ * @throws NumberFormatException if either version string is invalid
+ * @throws NullPointerException if either version string is null
*/
- public boolean isCompatibleWith(String version) throws NumberFormatException
+ public boolean isCompatibleWith(String version)
{
StringTokenizer versionTokens = new StringTokenizer(version, ".");
StringTokenizer specTokens = new StringTokenizer(specVersion, ".");
try
{
- while (versionTokens.hasMoreElements())
- {
- int vers = Integer.parseInt(versionTokens.nextToken());
- int spec = Integer.parseInt(specTokens.nextToken());
- if (spec < vers)
- return false;
- else if (spec > vers)
- return true;
- // They must be equal, next Token please!
- }
+ while (versionTokens.hasMoreElements())
+ {
+ int vers = Integer.parseInt(versionTokens.nextToken());
+ int spec = Integer.parseInt(specTokens.nextToken());
+ if (spec < vers)
+ return false;
+ else if (spec > vers)
+ return true;
+ // They must be equal, next Token please!
+ }
}
catch (NoSuchElementException e)
{
- // this must have been thrown by spec.netToken() so return false
- return false;
+ // This must have been thrown by spec.nextToken() so return false.
+ return false;
}
-
// They must have been exactly the same version.
// Or the specVersion has more subversions. That is also good.
return true;
* 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.
+ *
* @param name the name of the desired package
+ * @return the package by that name in the current ClassLoader
*/
public static Package getPackage(String name)
{
SecurityManager sm = System.getSecurityManager();
Class c = sm.getClassContext()[1];
ClassLoader cl = c.getClassLoader();
-
- if (cl != null)
- return cl.getPackage(name);
- else
- return null;
+ return cl != null ? cl.getPackage(name) : null;
}
/**
* Returns all the packages that are known to the callers class loader.
* It may return an empty array if the classloader of the caller is null.
+ *
+ * @return an array of all known packages
*/
public static Package[] getPackages()
{
SecurityManager sm = System.getSecurityManager();
Class c = sm.getClassContext()[1];
ClassLoader cl = c.getClassLoader();
-
- if (cl != null)
- return cl.getPackages();
- else
- return new Package[0];
+ // Sun's implementation returns the packages loaded by the bootstrap
+ // classloader if cl is null, but right now our bootstrap classloader
+ // does not create any Packages.
+ return cl != null ? cl.getPackages() : new Package[0];
}
- /**
+ /**
* Returns the hashCode of the name of this package.
+ *
+ * @return the hash code
*/
public int hashCode()
{
return name.hashCode();
}
- /**
- * Returns a string representation of this package name, specification,
- * implementation and class origin if sealed.
+ /**
+ * Returns a string representation of this package. It is specified to
+ * be <code>"package " + getName() + (getSpecificationTitle() == null
+ * ? "" : ", " + getSpecificationTitle()) + (getSpecificationVersion()
+ * == null ? "" : ", version " + getSpecificationVersion())</code>.
+ *
+ * @return the string representation of the package
*/
public String toString()
{
" version: " + implVersion +
" vendor: " + implVendor + " sealed: " + sealed;
}
-}
+} // class Package
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