* Annotations for the run-time package are read from {@code package-info.class} * at the same code source as classes in the run-time package. *
* The set of classes that make up the run-time package may implement a * particular specification. The specification title, version, and vendor * (indicating the owner/maintainer of the specification) can be provided * when the {@code Package} is defined. An application can ask if the * {@code Package} is compatible with a particular specification version * by using the {@link #isCompatibleWith Package.isCompatibleWith(String)} * method. In addition, information about the actual classes that make up the * run-time package can be provided when the Package is defined. * This information consists of an implementation title, version, and vendor * (indicating the supplier of the classes). *
* A {@code Package} may be explicitly defined with * the {@link ClassLoader#definePackage(String, String, String, String, * String, String, String, URL)} method. * The caller supplies the specification and implementation titles, versions, and * vendors. The caller also indicates whether the package is * {@linkplain java.util.jar.Attributes.Name#SEALED sealed}. * If a {@code Package} is not explicitly defined for a run-time package when * a class in that run-time package is defined, then a {@code Package} is * automatically defined by the class's defining class loader, as follows. *
* A {@code Package} automatically defined for classes in a named module has * the following properties: *
* A {@code Package} automatically defined for classes in an unnamed module * has the following properties: *
* A {@code Package} can be obtained with the {@link Package#getPackage * Package.getPackage(String)} and {@link ClassLoader#getDefinedPackage * ClassLoader.getDefinedPackage(String)} methods. * Every {@code Package} defined by a class loader can be obtained * with the {@link Package#getPackages Package.getPackages()} and * {@link ClassLoader#getDefinedPackages} methods. * * @implNote * The builtin class loaders * do not explicitly define {@code Package} objects for packages in * named modules. Instead those packages are automatically defined * and have no specification and implementation versioning information. * * @jvms 5.3 Creation and Loading * @see * The JAR File Specification: Package Sealing * @see ClassLoader#definePackage(String, String, String, String, String, String, String, URL) * * @since 1.2 * @revised 9 * @spec JPMS */ public class Package extends NamedPackage implements java.lang.reflect.AnnotatedElement { /** * Return the name of this package. * * @return The fully-qualified name of this package as defined in section 6.5.3 of * The Java™ Language Specification, * for example, {@code java.lang} */ public String getName() { return packageName(); } /** * Return the title of the specification that this package implements. * @return the specification title, {@code null} is returned if it is not known. */ public String getSpecificationTitle() { return versionInfo.specTitle; } /** * Returns the version number of the specification * that this package implements. * This version string must be a sequence of non-negative decimal * integers separated by "."'s and may have leading zeros. * When version strings are compared the most significant * numbers are compared. * * *
Specification version numbers use a syntax that consists of non-negative * decimal integers separated by periods ".", for example "2.0" or * "1.2.3.4.5.6.7". This allows an extensible number to be used to represent * major, minor, micro, etc. versions. The version specification is described * by the following formal grammar: *
** * @return the specification version, {@code null} is returned if it is not known. */ public String getSpecificationVersion() { return versionInfo.specVersion; } /** * Return the name of the organization, vendor, * or company that owns and maintains the specification * of the classes that implement this package. * @return the specification vendor, {@code null} is returned if it is not known. */ public String getSpecificationVendor() { return versionInfo.specVendor; } /** * Return the title of this package. * @return the title of the implementation, {@code null} is returned if it is not known. */ public String getImplementationTitle() { return versionInfo.implTitle; } /** * Return the version of this implementation. It consists of any string * assigned by the vendor of this implementation and does * not have any particular syntax specified or expected by the Java * runtime. It may be compared for equality with other * package version strings used for this implementation * by this vendor for this package. * @return the version of the implementation, {@code null} is returned if it is not known. */ public String getImplementationVersion() { return versionInfo.implVersion; } /** * Returns the vendor that implemented this package, {@code null} * is returned if it is not known. * @return the vendor that implemented this package, {@code null} * is returned if it is not known. * * @revised 9 * @spec JPMS */ public String getImplementationVendor() { return versionInfo.implVendor; } /** * Returns true if this package is sealed. * * @return true if the package is sealed, false otherwise */ public boolean isSealed() { return module().isNamed() || versionInfo.sealBase != null; } /** * Returns true if this package is sealed with respect to the specified * code source {@code url}. * * @param url the code source URL * @return true if this package is sealed with respect to the given {@code url} */ public boolean isSealed(URL url) { Objects.requireNonNull(url); URL sealBase = null; if (versionInfo != VersionInfo.NULL_VERSION_INFO) { sealBase = versionInfo.sealBase; } else { try { URI uri = location(); sealBase = uri != null ? uri.toURL() : null; } catch (MalformedURLException e) { } } return url.equals(sealBase); } /** * Compare this package's specification version with a * desired version. It returns true if * this packages specification version number is greater than or equal * to the desired version number.*
*- SpecificationVersion: *
- Digits RefinedVersionopt *
- RefinedVersion: *
- {@code .} Digits *
- {@code .} Digits RefinedVersion * *
- Digits: *
- Digit *
- Digits * *
- Digit: *
- any character for which {@link Character#isDigit} returns {@code true}, * e.g. 0, 1, 2, ... *
* * Version numbers are compared by sequentially comparing corresponding * components of the desired and specification strings. * Each component is converted as a decimal integer and the values * compared. * If the specification value is greater than the desired * value true is returned. If the value is less false is returned. * If the values are equal the period is skipped and the next pair of * components is compared. * * @param desired the version string of the desired version. * @return true if this package's version number is greater * than or equal to the desired version number * * @exception NumberFormatException if the current version is not known or * the desired or current version is not of the correct dotted form. */ public boolean isCompatibleWith(String desired) throws NumberFormatException { if (versionInfo.specVersion == null || versionInfo.specVersion.length() < 1) { throw new NumberFormatException("Empty version string"); } String [] sa = versionInfo.specVersion.split("\\.", -1); int [] si = new int[sa.length]; for (int i = 0; i < sa.length; i++) { si[i] = Integer.parseInt(sa[i]); if (si[i] < 0) throw NumberFormatException.forInputString("" + si[i], 10); } String [] da = desired.split("\\.", -1); int [] di = new int[da.length]; for (int i = 0; i < da.length; i++) { di[i] = Integer.parseInt(da[i]); if (di[i] < 0) throw NumberFormatException.forInputString("" + di[i], 10); } int len = Math.max(di.length, si.length); for (int i = 0; i < len; i++) { int d = (i < di.length ? di[i] : 0); int s = (i < si.length ? si[i] : 0); if (s < d) return false; if (s > d) return true; } return true; } /** * Finds a package by name in the caller's class loader and its * ancestors. *
* If the caller's class loader defines a {@code Package} of the given name, * the {@code Package} is returned. Otherwise, the ancestors of the * caller's class loader are searched recursively (parent by parent) * for a {@code Package} of the given name. *
* Calling this method is equivalent to calling {@link ClassLoader#getPackage} * on a {@code ClassLoader} instance which is the caller's class loader. * * @param name A package name, such as "{@code java.lang}". * @return The {@code Package} of the given name defined by the caller's * class loader or its ancestors, or {@code null} if not found. * * @throws NullPointerException * if {@code name} is {@code null}. * * @deprecated * If multiple class loaders delegate to each other and define classes * with the same package name, and one such loader relies on the lookup * behavior of {@code getPackage} to return a {@code Package} from * a parent loader, then the properties exposed by the {@code Package} * may not be as expected in the rest of the program. * For example, the {@code Package} will only expose annotations from the * {@code package-info.class} file defined by the parent loader, even if * annotations exist in a {@code package-info.class} file defined by * a child loader. A more robust approach is to use the * {@link ClassLoader#getDefinedPackage} method which returns * a {@code Package} for the specified class loader. * * @see ClassLoader#getDefinedPackage * * @revised 9 * @spec JPMS */ @CallerSensitive @Deprecated(since="9") @SuppressWarnings("deprecation") public static Package getPackage(String name) { ClassLoader l = ClassLoader.getClassLoader(Reflection.getCallerClass()); return l != null ? l.getPackage(name) : BootLoader.getDefinedPackage(name); } /** * Returns all of the {@code Package}s defined by the caller's class loader * and its ancestors. The returned array may contain more than one * {@code Package} object of the same package name, each defined by * a different class loader in the class loader hierarchy. *
* Calling this method is equivalent to calling {@link ClassLoader#getPackages}
* on a {@code ClassLoader} instance which is the caller's class loader.
*
* @return The array of {@code Package} objects defined by this
* class loader and its ancestors
*
* @see ClassLoader#getDefinedPackages
*
* @revised 9
* @spec JPMS
*/
@CallerSensitive
public static Package[] getPackages() {
ClassLoader cl = ClassLoader.getClassLoader(Reflection.getCallerClass());
return cl != null ? cl.getPackages() : BootLoader.packages().toArray(Package[]::new);
}
/**
* Return the hash code computed from the package name.
* @return the hash code computed from the package name.
*/
@Override
public int hashCode(){
return packageName().hashCode();
}
/**
* Returns the string representation of this Package.
* Its value is the string "package " and the package name.
* If the package title is defined it is appended.
* If the package version is defined it is appended.
* @return the string representation of the package.
*/
@Override
public String toString() {
String spec = versionInfo.specTitle;
String ver = versionInfo.specVersion;
if (spec != null && !spec.isEmpty())
spec = ", " + spec;
else
spec = "";
if (ver != null && !ver.isEmpty())
ver = ", version " + ver;
else
ver = "";
return "package " + packageName() + spec + ver;
}
private Class getPackageInfo() {
if (packageInfo == null) {
// find package-info.class defined by loader
String cn = packageName() + ".package-info";
Module module = module();
PrivilegedAction