public boolean isClassLoaded(String className) {
try {
ClassLoader cl = getClassLoader();
while (cl != null) {
// get loaded classes
Vector<?> loadedClasses = Util.getField(cl, ClassLoader.class, "classes", Vector.class);
for (Object object : loadedClasses) {
Class<?> clz = (Class<?>) object;
if (clz.getName().equals(className)) {
return true;
}
}
cl = cl.getParent();
}
// check bootstrap classes
Resource resource = Launcher.getBootstrapClassPath().getResource(Util.resolveName(className));
return resource != null;
} catch (RuntimeException e) {
if (reportErrorNoPermission) {
throw e;
} else {
return false;
}
}
}
public void testBootClassload() {
// 获取根类加载器所加载的全部URL数组
URL[] urls = sun.misc.Launcher.getBootstrapClassPath().getURLs();
for (int i = 0; i < urls.length; i++) {
System.out.println(urls[i].toExternalForm());
}
System.out.println(System.getProperty("sun.boot.class.path"));
}
public static void main(String[] args) {
URL[] urls = Launcher.getBootstrapClassPath().getURLs();
for (int i = 0; i < urls.length; i++) {
System.out.println(urls[i].toExternalForm());
}
System.out.println(System.getProperty("sun.boot.class.path"));
}
public static void main(String[] args) {
// 获取根类加载器所加载的全部URL数组
URL[] urls = sun.misc.Launcher.getBootstrapClassPath().getURLs();
// 遍历、输出根类加载器加载的全部URL
for (int i = 0; i < urls.length; i++) {
System.out.println(urls[i].toExternalForm());
}
for (URL url : urls) System.out.println(url);
}
public ClassLoader[] findClassLoaders(String className) {
List<ClassLoader> list = new ArrayList<ClassLoader>();
try {
ClassLoader cl = getClassLoader();
while (cl != null) {
Vector<?> loadedClasses = Util.getField(cl, ClassLoader.class, "classes", Vector.class);
boolean founded = false;
for (Object object : loadedClasses) {
Class<?> clz = (Class<?>) object;
if (clz.getName().equals(className)) {
list.add(clz.getClassLoader());
founded = true;
break;
}
}
if (!founded) {
Class<?> clz;
try {
clz =
Util.invokeMethod(
cl,
ClassLoader.class,
"findClass",
new Class[] {String.class},
new Object[] {className},
Class.class);
list.add(clz.getClassLoader());
} catch (InvocationTargetException e) {
if (!(e.getCause() instanceof ClassNotFoundException)) {
// ignore class not found
if (e.getCause() instanceof SecurityException) {
if (reportErrorNoPermission) {
throw (SecurityException) e.getCause();
}
}
}
}
}
cl = cl.getParent();
}
// check bootstrap classes
Resource resource = Launcher.getBootstrapClassPath().getResource(Util.resolveName(className));
if (resource != null) {
// bootstrap classloader in first
list.add(0, null);
}
} catch (RuntimeException e) {
if (reportErrorNoPermission) {
throw e;
}
}
return list.toArray(new ClassLoader[list.size()]);
}