[JavaIdentifierFactory] code documentation is inconsistent with the implementation

[Liyw979]

SootUp/sootup.java.core/src/main/java/sootup/java/core/JavaIdentifierFactory.java

Lines 108 to 139 in 76f7e78

	/**
	* Always creates a new ClassSignature. In opposite to PackageSignatures, ClassSignatures are not
	* cached because the are unique per class, and thus reusing them does not make sense.
	*
	* @param className the simple class name
	* @param packageName the Java package name; must not be null use empty string for the default
	* package {@link PackageName#DEFAULT_PACKAGE} the Java package name
	* @return a ClassSignature for a Java class
	* @throws NullPointerException if the given package name is null. Use the empty string to denote
	* the default package.
	*/
	@Override
	public JavaClassType getClassType(final String className, final String packageName) {
	PackageName packageIdentifier = getPackageName(packageName);
	return classTypeCache
	.asMap()
	.computeIfAbsent(
	className + packageName, (k) -> new JavaClassType(className, packageIdentifier));
	}
	/**
	* Always creates a new ClassSignature.
	*
	* @param fullyQualifiedClassName the fully-qualified name of the class
	* @return a ClassSignature for a Java Class
	*/
	@Override
	public JavaClassType getClassType(final String fullyQualifiedClassName) {
	String className = ClassUtils.getShortClassName(fullyQualifiedClassName);
	String packageName = ClassUtils.getPackageName(fullyQualifiedClassName);
	return getClassType(className, packageName);
	}

document: Always creates a new ClassSignature

implementation: map.computeIfAbsent(className + packageName, (k) -> new JavaClassType(className, packageIdentifier));

For a signature <Main: void liquid_test_entry(java.lang.String,java.lang.String)>
We now have 2 JavaClassType pointing to same object

What does Sootup actually hope for?

[swissiety]

documentation is wrong/outdated

[Liyw979]

Hi @swissiety
Is JavaIdentifierFactory designed to guarantee(make sure) that all "java.lang.String" points a same JavaClassType object (singleton pattern Flyweight Pattern) ?
Or map.computeIfAbsent(className + packageName, (k) -> new JavaClassType(className, packageIdentifier)); is just for saving some memory?

[swissiety]

from the documentation: no need to save memory, from the implementation: intention to make it possible to compare type via == with the sideeffect of saving some memory

[Liyw979]

And We should never do "new JavaClassType" outside the IdentifierFactory?