File	Doc	Category	Size	Date	Package
RemoteObjectInvocationHandler.java	API Doc	Java SE 5 API	8856	Fri Aug 26 14:57:12 BST 2005	java.rmi.server

RemoteObjectInvocationHandler

• java.lang.Object
  • java.rmi.server.RemoteObject

Fields Summary
private static final long	serialVersionUID
private static final MethodToHash_Maps	methodToHash_Maps A weak hash map, mapping classes to weak hash maps that map method objects to method hashes.

Constructors Summary
public RemoteObjectInvocationHandler(RemoteRef ref) Creates a new RemoteObjectInvocationHandler constructed with the specified RemoteRef. param ref the remote ref throws NullPointerException if ref is null super(ref); if (ref == null) { throw new NullPointerException(); }

Methods Summary
private static long	getMethodHash(java.lang.reflect.Method method) Returns the method hash for the specified method. Subsequent calls to "getMethodHash" passing the same method argument should be faster since this method caches internally the result of the method to method hash mapping. The method hash is calculated using the "computeMethodHash" method. param method the remote method return the method hash for the specified method Map map = methodToHash_Maps.getMap(method.getDeclaringClass()); Long hash = (Long) map.get(method); return hash.longValue();
public java.lang.Object	invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args) Processes a method invocation made on the encapsulating proxy instance, proxy, and returns the result. RemoteObjectInvocationHandler implements this method as follows: If method is one of the following methods, it is processed as described below: {@link Object#hashCode Object.hashCode}: Returns the hash code value for the proxy. {@link Object#equals Object.equals}: Returns true if the argument (args[0]) is an instance of a dynamic proxy class and this invocation handler is equal to the invocation handler of that argument, and returns false otherwise. {@link Object#toString Object.toString}: Returns a string representation of the proxy. Otherwise, a remote call is made as follows: If proxy is not an instance of the interface {@link Remote}, then an {@link IllegalArgumentException} is thrown. Otherwise, the {@link RemoteRef#invoke invoke} method is invoked on this invocation handler's RemoteRef, passing proxy, method, args, and the method hash (defined in section 8.3 of the "Java Remote Method Invocation (RMI) Specification") for method, and the result is returned. If an exception is thrown by RemoteRef.invoke and that exception is a checked exception that is not assignable to any exception in the throws clause of the method implemented by the proxy's class, then that exception is wrapped in an {@link UnexpectedException} and the wrapped exception is thrown. Otherwise, the exception thrown by invoke is thrown by this method. The semantics of this method are unspecified if the arguments could not have been produced by an instance of some valid dynamic proxy class containing this invocation handler. param proxy the proxy instance that the method was invoked on param method the Method instance corresponding to the interface method invoked on the proxy instance param args an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if the method takes no arguments return the value to return from the method invocation on the proxy instance throws Throwable the exception to throw from the method invocation on the proxy instance see if (method.getDeclaringClass() == Object.class) { return invokeObjectMethod(proxy, method, args); } else { return invokeRemoteMethod(proxy, method, args); }
private java.lang.Object	invokeObjectMethod(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args) Handles java.lang.Object methods. String name = method.getName(); if (name.equals("hashCode")) { return new Integer(hashCode()); } else if (name.equals("equals")) { Object obj = args[0]; boolean b = proxy == obj || (obj != null && Proxy.isProxyClass(obj.getClass()) && equals(Proxy.getInvocationHandler(obj))); return Boolean.valueOf(b); } else if (name.equals("toString")) { return proxyToString(proxy); } else { throw new IllegalArgumentException( "unexpected Object method: " + method); }
private java.lang.Object	invokeRemoteMethod(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args) Handles remote methods. try { if (!(proxy instanceof Remote)) { throw new IllegalArgumentException( "proxy not Remote instance"); } return ref.invoke((Remote) proxy, method, args, getMethodHash(method)); } catch (Exception e) { if (!(e instanceof RuntimeException)) { Class cl = proxy.getClass(); try { method = cl.getMethod(method.getName(), method.getParameterTypes()); } catch (NoSuchMethodException nsme) { throw (IllegalArgumentException) new IllegalArgumentException().initCause(nsme); } Class[] exTypes = method.getExceptionTypes(); Class thrownType = e.getClass(); for (int i = 0; i < exTypes.length; i++) { if (exTypes[i].isAssignableFrom(thrownType)) { throw e; } } e = new UnexpectedException("unexpected exception", e); } throw e; }
private java.lang.String	proxyToString(java.lang.Object proxy) Returns a string representation for a proxy that uses this invocation handler. Class[] interfaces = proxy.getClass().getInterfaces(); if (interfaces.length == 0) { return "Proxy[" + this + "]"; } String iface = interfaces[0].getName(); if (iface.equals("java.rmi.Remote") && interfaces.length > 1) { iface = interfaces[1].getName(); } int dot = iface.lastIndexOf('."); if (dot >= 0) { iface = iface.substring(dot + 1); } return "Proxy[" + iface + "," + this + "]";
private void	readObjectNoData() throws InvalidObjectException unconditionally throw new InvalidObjectException("no data in stream; class: " + this.getClass().getName());