Package edu.internet2.middleware.grouper.app.gsh.template

Class ByteArrayClassLoader

java.lang.Object

java.lang.ClassLoader

edu.internet2.middleware.grouper.app.gsh.template.ByteArrayClassLoader

public class ByteArrayClassLoader
extends ClassLoader

Classloader that defines a set of Java classes from in-memory bytecode. Used by GshTemplateClassLoaderRegistry as the per-template loader for a single compiled GSH Java template version. Parent delegation is standard parent-first: when asked for a class, the default loadClass() implementation in ClassLoader first asks the parent (which is Grouper's app classloader, holding GshTemplateV2, the Grouper API, JDK classes, and any helper jars), and only falls through to this loader's findClass() for classes the parent does not have. That guarantees GshTemplateV2, helper-jar classes, and JDK types are all resolved to a single Class object shared across the JVM, while the template's own bytecode is loaded here. One instance per template version. On a source change, the registry drops its reference to this loader and constructs a new one; the old loader becomes unreferenced and is eligible for GC once any in-flight executions holding references drain. GRP-7010

Constructor Summary

Constructors

Constructor	Description
ByteArrayClassLoader(ClassLoader parent, Map<String,byte[]> classNameToBytecode)

Method Summary

Modifier and Type	Method	Description
protected Class<?>	findClass(String name)	Define a class from this loader's bytecode map.

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findResource, findResources, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getName, getPackage, getPackages, getParent, getPlatformClassLoader, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, loadClass, loadClass, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Constructor Details

ByteArrayClassLoader

public ByteArrayClassLoader(ClassLoader parent,
 Map<String,byte[]> classNameToBytecode)

Parameters:

parent - typically GshTemplateV2.class.getClassLoader() — the loader that has Grouper's app classes, so the template's references to the Grouper API resolve through delegation

classNameToBytecode - bytecode for the template's class(es), keyed by FQN. Caller retains ownership of the map; this loader does not copy it but also does not mutate it.

Method Details

findClass

protected Class<?> findClass(String name)
                      throws ClassNotFoundException

Define a class from this loader's bytecode map. Called by the JDK's default loadClass() only after the parent loader has been asked first and returned ClassNotFoundException — i.e. for classes the parent does not have, which for our purposes are exactly the template's own classes.

Overrides:

findClass in class ClassLoader

Throws:

ClassNotFoundException