Class.java 文件源码

/**
 * Returns an array containing {@code Class} objects representing all
 * the public classes and interfaces that are members of the class
 * represented by this {@code Class} object.  This includes public
 * class and interface members inherited from superclasses and public class
 * and interface members declared by the class.  This method returns an
 * array of length 0 if this {@code Class} object has no public member
 * classes or interfaces.  This method also returns an array of length 0 if
 * this {@code Class} object represents a primitive type, an array
 * class, or void.
 *
 * @return the array of {@code Class} objects representing the public
 *         members of this class
 * @throws SecurityException
 *         If a security manager, <i>s</i>, is present and
 *         the caller's class loader is not the same as or an
 *         ancestor of the class loader for the current class and
 *         invocation of {@link SecurityManager#checkPackageAccess
 *         s.checkPackageAccess()} denies access to the package
 *         of this class.
 *
 * @since 1.1
 */
@CallerSensitive
public Class<?>[] getClasses() {
    SecurityManager sm = System.getSecurityManager();
    if (sm != null) {
        checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
    }

    // Privileged so this implementation can look at DECLARED classes,
    // something the caller might not have privilege to do.  The code here
    // is allowed to look at DECLARED classes because (1) it does not hand
    // out anything other than public members and (2) public member access
    // has already been ok'd by the SecurityManager.

    return java.security.AccessController.doPrivileged(
        new java.security.PrivilegedAction<>() {
            public Class<?>[] run() {
                List<Class<?>> list = new ArrayList<>();
                Class<?> currentClass = Class.this;
                while (currentClass != null) {
                    for (Class<?> m : currentClass.getDeclaredClasses()) {
                        if (Modifier.isPublic(m.getModifiers())) {
                            list.add(m);
                        }
                    }
                    currentClass = currentClass.getSuperclass();
                }
                return list.toArray(new Class<?>[0]);
            }
        });
}