* The runtime will pass the resulting helper object to the subsequent * calls to {@link #getContext(Object contextHelper)} and * {@link #setContext(Object contextHelper, Context cx)} methods. * In this way the implementation can use the helper to cache * information about current thread to make {@link Context} access faster. */ protected abstract Object getThreadContextHelper(); /** * Get {@link Context} instance associated with the current thread * or null if none. * * @param contextHelper The result of {@link #getThreadContextHelper()} * called from the current thread. */ protected abstract Context getContext(Object contextHelper); /** * Associate {@link Context} instance with the current thread or remove * the current association if cx is null. * * @param contextHelper The result of {@link #getThreadContextHelper()} * called from the current thread. */ protected abstract void setContext(Object contextHelper, Context cx); /** * Return the ClassLoader instance associated with the current thread. */ protected abstract ClassLoader getCurrentThreadClassLoader(); /** * In many JVMSs, public methods in private * classes are not accessible by default (Sun Bug #4071593). * VMBridge instance should try to workaround that via, for example, * calling method.setAccessible(true) when it is available. * The implementation is responsible to catch all possible exceptions * like SecurityException if the workaround is not available. * * @return true if it was possible to make method accessible * or false otherwise. */ protected abstract boolean tryToMakeAccessible(Object accessibleObject); /** * Create helper object to create later proxies implementing the specified * interfaces later. Under JDK 1.3 the implementation can look like: *
* return java.lang.reflect.Proxy.getProxyClass(..., interfaces).
* getConstructor(new Class[] {
* java.lang.reflect.InvocationHandler.class });
*
*
* @param interfaces Array with one or more interface class objects.
*/
protected Object getInterfaceProxyHelper(ContextFactory cf,
Class[] interfaces)
{
throw Context.reportRuntimeError(
"VMBridge.getInterfaceProxyHelper is not supported");
}
/**
* Create proxy object for {@link InterfaceAdapter}. The proxy should call
* {@link InterfaceAdapter#invoke(ContextFactory cf,
* Object target,
* Scriptable topScope,
* Method method,
* Object[] args)}
* as implementation of interface methods associated with
* proxyHelper.
*
* @param proxyHelper The result of the previous call to
* {@link #getInterfaceProxyHelper(ContextFactory, Class[])}.
*/
protected Object newInterfaceProxy(Object proxyHelper,
ContextFactory cf,
InterfaceAdapter adapter,
Object target,
Scriptable topScope)
{
throw Context.reportRuntimeError(
"VMBridge.newInterfaceProxy is not supported");
}
/**
* Returns whether or not a given member (method or constructor)
* has variable arguments.
* Variable argument methods have only been supported in Java since
* JDK 1.5.
*/
protected abstract boolean isVarArgs(Member member);
/**
* If "obj" is a java.util.Iterator or a java.lang.Iterable, return a
* wrapping as a JavaScript Iterator. Otherwise, return null.
* This method is in VMBridge since Iterable is a JDK 1.5 addition.
*/
public Iterator getJavaIterator(Context cx, Scriptable scope, Object obj) {
if (obj instanceof Wrapper) {
Object unwrapped = ((Wrapper) obj).unwrap();
Iterator iterator = null;
if (unwrapped instanceof Iterator)
iterator = (Iterator) unwrapped;
return iterator;
}
return null;
}
}