How to use

ParentJarClassLoader

in

juzu.impl.common

public Dynamic(Logger logger, ClassLoader baseClassLoader, ReadFileSystem<S> source) {
 super(logger);
 //
 this.classLoader = null;
 this.baseClassLoader = baseClassLoader;
 this.classPathLoader = new ParentJarClassLoader(baseClassLoader);
 this.scanner = FileSystemScanner.createHashing(source);
 this.snapshot = scanner.take();
 this.classPath = null;
 this.failed = false;
}

@Override
protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
 Class<?> found = super.loadClass(name, resolve);
 if (found.getClassLoader() == super.getParent()) {
  URL url = super.getResource(name.replace('.', '/') + ".class");
  if (shouldLoad(url)) {
   return found;
  } else {
   throw new ClassNotFoundException();
  }
 }
 return found;
}

public Dynamic(Logger logger, ClassLoader baseClassLoader, ReadFileSystem<S> source) {
 super(logger);
 //
 this.classLoader = null;
 this.baseClassLoader = baseClassLoader;
 this.classPathLoader = new ParentJarClassLoader(baseClassLoader);
 this.scanner = FileSystemScanner.createHashing(source);
 this.snapshot = scanner.take();
 this.classPath = null;
 this.failed = false;
}

@Override
protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
 Class<?> found = super.loadClass(name, resolve);
 if (found.getClassLoader() == super.getParent()) {
  URL url = super.getResource(name.replace('.', '/') + ".class");
  if (shouldLoad(url)) {
   return found;
  } else {
   throw new ClassNotFoundException();
  }
 }
 return found;
}

 @Test
 public void testLoadingFromAncestor() throws Exception {
  ClassLoader cl = new ParentJarClassLoader(new URLClassLoader(new URL[0], effectiveLoader));

  // We can load from file
  assertSame(cl.loadClass(Dev.class.getName()), effectiveLoader.loadClass(Dev.class.getName()));
  URL classesResource = cl.getResource("classes_resource");
  assertNotNull(classesResource);
  assertEquals(Collections.singletonList(classesResource), Tools.list(cl.getResources("classes_resource")));

  // We can load from jar
  assertSame(effectiveLoader.loadClass(Lib.class.getName()), cl.loadClass(Lib.class.getName()));
  URL libResource = cl.getResource("lib_resource");
  assertNotNull(libResource);
  assertEquals("lib_resource_value", Tools.read(libResource));
  assertEquals(Collections.singletonList(libResource), Tools.list(cl.getResources("lib_resource")));
 }
}

@Override
public URL getResource(String name) {
 URL url;
 try {
  url = (URL)findResource.invoke(parent, name);
 }
 catch (Exception e) {
  throw new UnsupportedOperationException("Not yet handled", e);
 }
 if (url != null) {
  if (shouldLoad(url)) {
   return url;
  } else {
   return null;
  }
 } else {
  return super.getResource(name);
 }
}

 @Test
 public void testLoadingFromAncestor() throws Exception {
  ClassLoader cl = new ParentJarClassLoader(new URLClassLoader(new URL[0], effectiveLoader));

  // We can load from file
  assertSame(cl.loadClass(Dev.class.getName()), effectiveLoader.loadClass(Dev.class.getName()));
  URL classesResource = cl.getResource("classes_resource");
  assertNotNull(classesResource);
  assertEquals(Collections.singletonList(classesResource), Tools.list(cl.getResources("classes_resource")));

  // We can load from jar
  assertSame(effectiveLoader.loadClass(Lib.class.getName()), cl.loadClass(Lib.class.getName()));
  URL libResource = cl.getResource("lib_resource");
  assertNotNull(libResource);
  assertEquals("lib_resource_value", Tools.read(libResource));
  assertEquals(Collections.singletonList(libResource), Tools.list(cl.getResources("lib_resource")));
 }
}

@Override
public URL getResource(String name) {
 URL url;
 try {
  url = (URL)findResource.invoke(parent, name);
 }
 catch (Exception e) {
  throw new UnsupportedOperationException("Not yet handled", e);
 }
 if (url != null) {
  if (shouldLoad(url)) {
   return url;
  } else {
   return null;
  }
 } else {
  return super.getResource(name);
 }
}

@Test
public void testLoadingLoadingFromParent() throws Exception {
 // We cannot load from file
 ClassLoader cl = new ParentJarClassLoader(effectiveLoader);
 try {
  cl.loadClass(Dev.class.getName());
  fail();
 }
 catch (ClassNotFoundException e) {
 }
 URL classesResource = cl.getResource("classes_resource");
 assertNull(classesResource);
 assertFalse(cl.getResources("classes_resource").hasMoreElements());
 assertEquals(Collections.emptyList(), Tools.list(cl.getResources("classes_resource")));
 // We can load from jar
 assertSame(effectiveLoader.loadClass(Lib.class.getName()), cl.loadClass(Lib.class.getName()));
 URL libResource = cl.getResource("lib_resource");
 assertNotNull(libResource);
 assertEquals("lib_resource_value", Tools.read(libResource));
 Tools.list(cl.getResources("lib_resource").hasMoreElements());
 assertEquals(Collections.singletonList(libResource), Tools.list(cl.getResources("lib_resource")));
}

@Test
public void testLoadingLoadingFromParent() throws Exception {
 // We cannot load from file
 ClassLoader cl = new ParentJarClassLoader(effectiveLoader);
 try {
  cl.loadClass(Dev.class.getName());
  fail();
 }
 catch (ClassNotFoundException e) {
 }
 URL classesResource = cl.getResource("classes_resource");
 assertNull(classesResource);
 assertFalse(cl.getResources("classes_resource").hasMoreElements());
 assertEquals(Collections.emptyList(), Tools.list(cl.getResources("classes_resource")));
 // We can load from jar
 assertSame(effectiveLoader.loadClass(Lib.class.getName()), cl.loadClass(Lib.class.getName()));
 URL libResource = cl.getResource("lib_resource");
 assertNotNull(libResource);
 assertEquals("lib_resource_value", Tools.read(libResource));
 Tools.list(cl.getResources("lib_resource").hasMoreElements());
 assertEquals(Collections.singletonList(libResource), Tools.list(cl.getResources("lib_resource")));
}