Package org.junit.platform.commons.util

Class PackageUtils

  • @API(status=INTERNAL,
     since="1.0")
public final class PackageUtils
extends java.lang.Object
    Collection of utilities for working with packages.

    DISCLAIMER

    These utilities are intended solely for usage within the JUnit framework itself. Any usage by external parties is not supported. Use at your own risk!

    Since:
    1.0

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      (package private) static class  PackageUtils.JavaNameUtils
      Collection of utilities for working with qualified names in Java.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) static java.lang.String DEFAULT_PACKAGE_NAME  
      private static java.util.regex.Pattern DOT_PATTERN
      Compiled "\." pattern used to split canonical package (and type) names.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private PackageUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void assertPackageNameIsValid​(java.lang.String packageName)
      Assert that the supplied package name is valid in terms of Java syntax.
      static java.util.Optional<java.lang.String> getAttribute​(java.lang.Class<?> type, java.lang.String name)
      Get the value of the specified attribute name, specified as a string, or an empty Optional if the attribute was not found.
      static java.util.Optional<java.lang.String> getAttribute​(java.lang.Class<?> type, java.util.function.Function<java.lang.Package,​java.lang.String> function)
      Get the package attribute for the supplied type using the supplied function.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • DEFAULT_PACKAGE_NAME

        static final java.lang.String DEFAULT_PACKAGE_NAME
        See Also:
        Constant Field Values

      • DOT_PATTERN

        private static final java.util.regex.Pattern DOT_PATTERN
        Compiled "\." pattern used to split canonical package (and type) names.

    • Constructor Detail

      • PackageUtils

        private PackageUtils()

    • Method Detail

      • assertPackageNameIsValid

        public static void assertPackageNameIsValid​(java.lang.String packageName)
        Assert that the supplied package name is valid in terms of Java syntax.

        Note: this method does not actually verify if the named package exists in the classpath.

        The default package is represented by an empty string ("").

        Parameters:
        packageName - the package name to validate
        Throws:
        PreconditionViolationException - if the supplied package name is null, contains only whitespace, or contains parts that are not valid in terms of Java syntax (e.g., containing keywords such as void, import, etc.)
        See Also:
        PackageUtils.JavaNameUtils.isJavaName(String)

      • getAttribute

        public static java.util.Optional<java.lang.String> getAttribute​(java.lang.Class<?> type,
                                                                java.util.function.Function<java.lang.Package,​java.lang.String> function)
        Get the package attribute for the supplied type using the supplied function.

        This method only returns a non-empty Optional value holder if the class loader for the supplied type created a Package object and the supplied function does not return null when applied.

        Parameters:
        type - the type to get the package attribute for
        function - a function that computes the package attribute value (e.g., Package::getImplementationTitle); never null
        Returns:
        an Optional containing the attribute value; never null but potentially empty
        Throws:
        PreconditionViolationException - if the supplied type or function is null
        See Also:
        Class.getPackage(), Package.getImplementationTitle(), Package.getImplementationVersion()

      • getAttribute

        public static java.util.Optional<java.lang.String> getAttribute​(java.lang.Class<?> type,
                                                                java.lang.String name)
        Get the value of the specified attribute name, specified as a string, or an empty Optional if the attribute was not found. The attribute name is case-insensitive.

        This method also returns an empty Optional value holder if any exception is caught while loading the manifest file via the JAR file of the specified type.

        Parameters:
        type - the type to get the attribute for
        name - the attribute name as a string
        Returns:
        an Optional containing the attribute value; never null but potentially empty
        Throws:
        PreconditionViolationException - if the supplied type is null or the specified name is blank
        See Also:
        Manifest.getMainAttributes()