package com.apress.progwt.server.gwt;
/*
* Copyright 2007 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException;
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.server.rpc.RPCRequest;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.google.gwt.user.server.rpc.SerializationPolicy;
import com.google.gwt.user.server.rpc.SerializationPolicyProvider;
import com.google.gwt.user.server.rpc.UnexpectedException;
import com.google.gwt.user.server.rpc.impl.LegacySerializationPolicy;
import com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader;
/**
* Utility class for integrating with the RPC system. This class exposes
* methods for decoding of RPC requests, encoding of RPC responses, and
* invocation of RPC calls on service objects. The operations exposed by
* this class can be reused by framework implementors such as Spring and
* G4jsf to support a wide range of service invocation policies.
*
* <h3>Canonical Example</h3>
* The following example demonstrates the canonical way to use this class.
*
* {@example com.google.gwt.examples.rpc.server.CanonicalExample#processCall(String)}
*
* <h3>Advanced Example</h3>
* The following example shows a more advanced way of using this class to
* create an adapter between GWT RPC entities and POJOs.
*
* {@example com.google.gwt.examples.rpc.server.AdvancedExample#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)}
*/
public final class RPC1524 {
/**
* Maps primitive wrapper classes to their corresponding primitive
* class.
*/
private static final Map<Class<?>, Class<?>> PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS = new HashMap<Class<?>, Class<?>>();
/**
* Static map of classes to sets of interfaces (e.g. classes).
* Optimizes lookup of interfaces for security.
*/
private static Map<Class<?>, Set<String>> serviceToImplementedInterfacesMap;
private static final HashMap<String, Class<?>> TYPE_NAMES;
static {
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Boolean.class,
Boolean.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Byte.class,
Byte.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Character.class,
Character.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Double.class,
Double.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Float.class,
Float.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Integer.class,
Integer.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Long.class,
Long.TYPE);
PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS.put(Short.class,
Short.TYPE);
TYPE_NAMES = new HashMap<String, Class<?>>();
TYPE_NAMES.put("Z", boolean.class);
TYPE_NAMES.put("B", byte.class);
TYPE_NAMES.put("C", char.class);
TYPE_NAMES.put("D", double.class);
TYPE_NAMES.put("F", float.class);
TYPE_NAMES.put("I", int.class);
TYPE_NAMES.put("J", long.class);
TYPE_NAMES.put("S", short.class);
serviceToImplementedInterfacesMap = new HashMap<Class<?>, Set<String>>();
}
/**
* Returns an {@link RPCRequest} that is built by decoding the
* contents of an encoded RPC request.
*
* <p>
* This method is equivalent to calling
* {@link #decodeRequest(String, Class)} with <code>null</code> for
* the type parameter.
* </p>
*
* @param encodedRequest
* a string that encodes the {@link RemoteService}
* interface, the service method to call, and the arguments
* to for the service method
* @return an {@link RPCRequest} instance
*
* @throws IncompatibleRemoteServiceException
* if any of the following conditions apply:
* <ul>
* <li>if the types in the encoded request cannot be
* deserialized</li>
* <li>if the {@link ClassLoader} acquired from
* <code>Thread.currentThread().getContextClassLoader()</code>
* cannot load the service interface or any of the types
* specified in the encodedRequest</li>
* <li>the requested interface is not assignable to
* {@link RemoteService}</li>
* <li>the service method requested in the encodedRequest
* is not a member of the requested service interface</li>
* <li>the type parameter is not <code>null</code> and
* is not assignable to the requested
* {@link RemoteService} interface
* </ul>
*/
public static RPCRequest decodeRequest(String encodedRequest) {
return decodeRequest(encodedRequest, null);
}
/**
* Returns an {@link RPCRequest} that is built by decoding the
* contents of an encoded RPC request and optionally validating that
* type can handle the request. If the type parameter is not
* <code>null</code>, the implementation checks that the type is
* assignable to the {@link RemoteService} interface requested in the
* encoded request string.
*
* <p>
* Invoking this method with <code>null</code> for the type
* parameter, <code>decodeRequest(encodedRequest, null)</code>, is
* equivalent to calling <code>decodeRequest(encodedRequest)</code>.
* </p>
*
* @param encodedRequest
* a string that encodes the {@link RemoteService}
* interface, the service method, and the arguments to pass
* to the service method
* @param type
* if not <code>null</code>, the implementation checks
* that the type is assignable to the {@link RemoteService}
* interface encoded in the encoded request string.
* @return an {@link RPCRequest} instance
*
* @throws NullPointerException
* if the encodedRequest is <code>null</code>
* @throws IllegalArgumentException
* if the encodedRequest is an empty string
* @throws IncompatibleRemoteServiceException
* if any of the following conditions apply:
* <ul>
* <li>if the types in the encoded request cannot be
* deserialized</li>
* <li>if the {@link ClassLoader} acquired from
* <code>Thread.currentThread().getContextClassLoader()</code>
* cannot load the service interface or any of the types
* specified in the encodedRequest</li>
* <li>the requested interface is not assignable to
* {@link RemoteService}</li>
* <li>the service method requested in the encodedRequest
* is not a member of the requested service interface</li>
* <li>the type parameter is not <code>null</code> and
* is not assignable to the requested
* {@link RemoteService} interface
* </ul>
*/
public static RPCRequest decodeRequest(String encodedRequest,
Class<?> type) {
return decodeRequest(encodedRequest, type, null);
}
/**
* Returns an {@link RPCRequest} that is built by decoding the
* contents of an encoded RPC request and optionally validating that
* type can handle the request. If the type parameter is not
* <code>null</code>, the implementation checks that the type is
* assignable to the {@link RemoteService} interface requested in the
* encoded request string.
*
* <p>
* If the serializationPolicyProvider parameter is not
* <code>null</code>, it is asked for a {@link SerializationPolicy}
* to use to restrict the set of types that can be decoded from the
* request. If this parameter is <code>null</code>, then only
* subtypes of
* {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable}
* or types which have custom field serializers can be decoded.
* </p>
*
* <p>
* Invoking this method with <code>null</code> for the type
* parameter, <code>decodeRequest(encodedRequest, null)</code>, is
* equivalent to calling <code>decodeRequest(encodedRequest)</code>.
* </p>
*
* @param encodedRequest
* a string that encodes the {@link RemoteService}
* interface, the service method, and the arguments to pass
* to the service method
* @param type
* if not <code>null</code>, the implementation checks
* that the type is assignable to the {@link RemoteService}
* interface encoded in the encoded request string.
* @param serializationPolicyProvider
* if not <code>null</code>, the implementation asks
* this provider for a {@link SerializationPolicy} which
* will be used to restrict the set of types that can be
* decoded from this request
* @return an {@link RPCRequest} instance
*
* @throws NullPointerException
* if the encodedRequest is <code>null</code>
* @throws IllegalArgumentException
* if the encodedRequest is an empty string
* @throws IncompatibleRemoteServiceException
* if any of the following conditions apply:
* <ul>
* <li>if the types in the encoded request cannot be
* deserialized</li>
* <li>if the {@link ClassLoader} acquired from
* <code>Thread.currentThread().getContextClassLoader()</code>
* cannot load the service interface or any of the types
* specified in the encodedRequest</li>
* <li>the requested interface is not assignable to
* {@link RemoteService}</li>
* <li>the service method requested in the encodedRequest
* is not a member of the requested service interface</li>
* <li>the type parameter is not <code>null</code> and
* is not assignable to the requested
* {@link RemoteService} interface
* </ul>
*/
public static RPCRequest decodeRequest(String encodedRequest,
Class<?> type,
SerializationPolicyProvider serializationPolicyProvider) {
if (encodedRequest == null) {
throw new NullPointerException(
"encodedRequest cannot be null");
}
if (encodedRequest.length() == 0) {
throw new IllegalArgumentException(
"encodedRequest cannot be empty");
}
ClassLoader classLoader = Thread.currentThread()
.getContextClassLoader();
try {
ServerSerializationStreamReader streamReader = new ServerSerializationStreamReader(
classLoader, serializationPolicyProvider);
streamReader.prepareToRead(encodedRequest);
// Read the name of the RemoteService interface
String serviceIntfName = streamReader.readString();
if (type != null) {
if (!implementsInterface(type, serviceIntfName)) {
// The service does not implement the requested
// interface
throw new IncompatibleRemoteServiceException(
"Blocked attempt to access interface '"
+ serviceIntfName
+ "', which is not implemented by '"
+ printTypeName(type)
+ "'; this is either misconfiguration or a hack attempt");
}
}
SerializationPolicy serializationPolicy = streamReader
.getSerializationPolicy();
Class<?> serviceIntf;
try {
serviceIntf = getClassFromSerializedName(serviceIntfName,
classLoader);
if (!RemoteService.class.isAssignableFrom(serviceIntf)) {
// The requested interface is not a RemoteService
// interface
throw new IncompatibleRemoteServiceException(
"Blocked attempt to access interface '"
+ printTypeName(serviceIntf)
+ "', which doesn't extend RemoteService; this is either misconfiguration or a hack attempt");
}
} catch (ClassNotFoundException e) {
throw new IncompatibleRemoteServiceException(
"Could not locate requested interface '"
+ serviceIntfName
+ "' in default classloader", e);
}
String serviceMethodName = streamReader.readString();
int paramCount = streamReader.readInt();
Class<?>[] parameterTypes = new Class[paramCount];
for (int i = 0; i < parameterTypes.length; i++) {
String paramClassName = streamReader.readString();
try {
parameterTypes[i] = getClassFromSerializedName(
paramClassName, classLoader);
} catch (ClassNotFoundException e) {
throw new IncompatibleRemoteServiceException(
"Parameter " + i
+ " of is of an unknown type '"
+ paramClassName + "'", e);
}
}
try {
Method method = serviceIntf.getMethod(serviceMethodName,
parameterTypes);
Object[] parameterValues = new Object[parameterTypes.length];
for (int i = 0; i < parameterValues.length; i++) {
parameterValues[i] = streamReader
.deserializeValue(parameterTypes[i]);
}
return new RPCRequest(method, parameterValues,
serializationPolicy);
} catch (NoSuchMethodException e) {
throw new IncompatibleRemoteServiceException(
formatMethodNotFoundErrorMessage(serviceIntf,
serviceMethodName, parameterTypes));
}
} catch (SerializationException ex) {
throw new IncompatibleRemoteServiceException(ex.getMessage(),
ex);
}
}
/**
* Returns a string that encodes an exception. If method is not
* <code>null</code>, it is an error if the exception is not in the
* method's list of checked exceptions.
*
* @param serviceMethod
* the method that threw the exception, may be
* <code>null</code>
* @param cause
* the {@link Throwable} that was thrown
* @return a string that encodes the exception
*
* @throws NullPointerException
* if the the cause is <code>null</code>
* @throws SerializationException
* if the result cannot be serialized
* @throws UnexpectedException
* if the result was an unexpected exception (a checked
* exception not declared in the serviceMethod's
* signature)
*/
public static String encodeResponseForFailure(Method serviceMethod,
Throwable cause) throws SerializationException {
return encodeResponseForFailure(serviceMethod, cause,
new ServerSerializationStreamWriter_1_5_3(
getDefaultSerializationPolicy()));
}
/**
* Returns a string that encodes an exception. If method is not
* <code>null</code>, it is an error if the exception is not in the
* method's list of checked exceptions.
*
* <p>
* If the serializationPolicy parameter is not <code>null</code>,
* it is used to determine what types can be encoded as part of this
* response. If this parameter is <code>null</code>, then only
* subtypes of
* {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable}
* or types which have custom field serializers may be encoded.
* </p>
*
* @param serviceMethod
* the method that threw the exception, may be
* <code>null</code>
* @param cause
* the {@link Throwable} that was thrown
* @param serializationPolicy
* determines the serialization policy to be used
* @return a string that encodes the exception
*
* @throws NullPointerException
* if the the cause or the serializationPolicy are
* <code>null</code>
* @throws SerializationException
* if the result cannot be serialized
* @throws UnexpectedException
* if the result was an unexpected exception (a checked
* exception not declared in the serviceMethod's
* signature)
*/
public static String encodeResponseForFailure(Method serviceMethod,
Throwable cause,
ServerSerializationStreamWriter_1_5_3 streamWriter)
throws SerializationException {
if (cause == null) {
throw new NullPointerException("cause cannot be null");
}
if (streamWriter == null) {
throw new NullPointerException("streamWriter");
}
if (serviceMethod != null
&& !RPC1524.isExpectedException(serviceMethod, cause)) {
throw new UnexpectedException("Service method '"
+ getSourceRepresentation(serviceMethod)
+ "' threw an unexpected exception: "
+ cause.toString(), cause);
}
return encodeResponse(cause.getClass(), cause, true, streamWriter);
}
/**
* Returns a string that encodes the object. It is an error to try to
* encode an object that is not assignable to the service method's
* return type.
*
* @param serviceMethod
* the method whose result we are encoding
* @param object
* the instance that we wish to encode
* @return a string that encodes the object, if the object is
* compatible with the service method's declared return type
*
* @throws IllegalArgumentException
* if the result is not assignable to the service method's
* return type
* @throws NullPointerException
* if the service method is <code>null</code>
* @throws SerializationException
* if the result cannot be serialized
*/
public static String encodeResponseForSuccess(Method serviceMethod,
Object object) throws SerializationException {
return encodeResponseForSuccess(serviceMethod, object,
new ServerSerializationStreamWriter_1_5_3(
getDefaultSerializationPolicy()));
}
/**
* Returns a string that encodes the object. It is an error to try to
* encode an object that is not assignable to the service method's
* return type.
*
* <p>
* If the serializationPolicy parameter is not <code>null</code>,
* it is used to determine what types can be encoded as part of this
* response. If this parameter is <code>null</code>, then only
* subtypes of
* {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable}
* or types which have custom field serializers may be encoded.
* </p>
*
* @param serviceMethod
* the method whose result we are encoding
* @param object
* the instance that we wish to encode
* @param serializationPolicy
* determines the serialization policy to be used
* @return a string that encodes the object, if the object is
* compatible with the service method's declared return type
*
* @throws IllegalArgumentException
* if the result is not assignable to the service method's
* return type
* @throws NullPointerException
* if the serviceMethod or the serializationPolicy are
* <code>null</code>
* @throws SerializationException
* if the result cannot be serialized
*/
public static String encodeResponseForSuccess(Method serviceMethod,
Object object,
ServerSerializationStreamWriter_1_5_3 streamWriter)
throws SerializationException {
if (serviceMethod == null) {
throw new NullPointerException("serviceMethod cannot be null");
}
if (streamWriter == null) {
throw new NullPointerException("streamWriter");
}
Class<?> methodReturnType = serviceMethod.getReturnType();
if (methodReturnType != void.class && object != null) {
Class<?> actualReturnType;
if (methodReturnType.isPrimitive()) {
actualReturnType = getPrimitiveClassFromWrapper(object
.getClass());
} else {
actualReturnType = object.getClass();
}
if (actualReturnType == null
|| !methodReturnType
.isAssignableFrom(actualReturnType)) {
throw new IllegalArgumentException(
"Type '"
+ printTypeName(object.getClass())
+ "' does not match the return type in the method's signature: '"
+ getSourceRepresentation(serviceMethod)
+ "'");
}
}
return encodeResponse(methodReturnType, object, false,
streamWriter);
}
/**
* Returns a default serialization policy.
*
* @return the default serialization policy.
*/
public static SerializationPolicy getDefaultSerializationPolicy() {
return LegacySerializationPolicy.getInstance();
}
/**
* Returns a string that encodes the result of calling a service
* method, which could be the value returned by the method or an
* exception thrown by it.
*
* <p>
* This method does no security checking; security checking must be
* done on the method prior to this invocation.
* </p>
*
* @param target
* instance on which to invoke the serviceMethod
* @param serviceMethod
* the method to invoke
* @param args
* arguments used for the method invocation
* @return a string which encodes either the method's return or a
* checked exception thrown by the method
*
* @throws SecurityException
* if the method cannot be accessed or if the number or
* type of actual and formal arguments differ
* @throws SerializationException
* if an object could not be serialized by the stream
* @throws UnexpectedException
* if the serviceMethod throws a checked exception that is
* not declared in its signature
*/
public static String invokeAndEncodeResponse(Object target,
Method serviceMethod, Object[] args)
throws SerializationException {
return invokeAndEncodeResponse(target, serviceMethod, args,
getDefaultSerializationPolicy());
}
/**
* Returns a string that encodes the result of calling a service
* method, which could be the value returned by the method or an
* exception thrown by it.
*
* <p>
* If the serializationPolicy parameter is not <code>null</code>,
* it is used to determine what types can be encoded as part of this
* response. If this parameter is <code>null</code>, then only
* subtypes of
* {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable}
* or types which have custom field serializers may be encoded.
* </p>
*
* <p>
* This method does no security checking; security checking must be
* done on the method prior to this invocation.
* </p>
*
* @param target
* instance on which to invoke the serviceMethod
* @param serviceMethod
* the method to invoke
* @param args
* arguments used for the method invocation
* @param serializationPolicy
* determines the serialization policy to be used
* @return a string which encodes either the method's return or a
* checked exception thrown by the method
*
* @throws NullPointerException
* if the serviceMethod or the serializationPolicy are
* <code>null</code>
* @throws SecurityException
* if the method cannot be accessed or if the number or
* type of actual and formal arguments differ
* @throws SerializationException
* if an object could not be serialized by the stream
* @throws UnexpectedException
* if the serviceMethod throws a checked exception that is
* not declared in its signature
*/
public static String invokeAndEncodeResponse(Object target,
Method serviceMethod, Object[] args,
SerializationPolicy serializationPolicy)
throws SerializationException {
return invokeAndEncodeResponse(target, serviceMethod, args,
new ServerSerializationStreamWriter_1_5_3(
serializationPolicy));
}
public static String invokeAndEncodeResponse(Object target,
Method serviceMethod, Object[] args,
ServerSerializationStreamWriter_1_5_3 streamWriter)
throws SerializationException {
if (serviceMethod == null) {
throw new NullPointerException("serviceMethod");
}
if (streamWriter == null) {
throw new NullPointerException("streamWriter");
}
String responsePayload;
try {
Object result = serviceMethod.invoke(target, args);
responsePayload = encodeResponseForSuccess(serviceMethod,
result, streamWriter);
} catch (IllegalAccessException e) {
SecurityException securityException = new SecurityException(
formatIllegalAccessErrorMessage(target, serviceMethod));
securityException.initCause(e);
throw securityException;
} catch (IllegalArgumentException e) {
SecurityException securityException = new SecurityException(
formatIllegalArgumentErrorMessage(target,
serviceMethod, args));
securityException.initCause(e);
throw securityException;
} catch (InvocationTargetException e) {
// Try to encode the caught exception
//
Throwable cause = e.getCause();
responsePayload = encodeResponseForFailure(serviceMethod,
cause, streamWriter);
}
return responsePayload;
}
/**
* Returns a string that encodes the results of an RPC call. Private
* overload that takes a flag signaling the preamble of the response
* payload.
*
* @param object
* the object that we wish to send back to the client
* @param wasThrown
* if true, the object being returned was an exception
* thrown by the service method; if false, it was the
* result of the service method's invocation
* @return a string that encodes the response from a service method
* @throws SerializationException
* if the object cannot be serialized
*/
private static String encodeResponse(Class<?> responseClass,
Object object, boolean wasThrown,
ServerSerializationStreamWriter_1_5_3 stream)
throws SerializationException {
stream.prepareToWrite();
if (responseClass != void.class) {
stream.serializeValue(object, responseClass);
}
String bufferStr = (wasThrown ? "//EX" : "//OK")
+ stream.toString();
return bufferStr;
}
private static String formatIllegalAccessErrorMessage(Object target,
Method serviceMethod) {
StringBuffer sb = new StringBuffer();
sb.append("Blocked attempt to access inaccessible method '");
sb.append(getSourceRepresentation(serviceMethod));
sb.append("'");
if (target != null) {
sb.append(" on target '");
sb.append(printTypeName(target.getClass()));
sb.append("'");
}
sb.append("; this is either misconfiguration or a hack attempt");
return sb.toString();
}
private static String formatIllegalArgumentErrorMessage(
Object target, Method serviceMethod, Object[] args) {
StringBuffer sb = new StringBuffer();
sb.append("Blocked attempt to invoke method '");
sb.append(getSourceRepresentation(serviceMethod));
sb.append("'");
if (target != null) {
sb.append(" on target '");
sb.append(printTypeName(target.getClass()));
sb.append("'");
}
sb.append(" with invalid arguments");
if (args != null && args.length > 0) {
sb.append(Arrays.asList(args));
}
return sb.toString();
}
private static String formatMethodNotFoundErrorMessage(
Class<?> serviceIntf, String serviceMethodName,
Class<?>[] parameterTypes) {
StringBuffer sb = new StringBuffer();
sb.append("Could not locate requested method '");
sb.append(serviceMethodName);
sb.append("(");
for (int i = 0; i < parameterTypes.length; ++i) {
if (i > 0) {
sb.append(", ");
}
sb.append(printTypeName(parameterTypes[i]));
}
sb.append(")'");
sb.append(" in interface '");
sb.append(printTypeName(serviceIntf));
sb.append("'");
return sb.toString();
}
/**
* Returns the {@link Class} instance for the named class or primitive
* type.
*
* @param serializedName
* the serialized name of a class or primitive type
* @param classLoader
* the classLoader used to load {@link Class}es
* @return Class instance for the given type name
* @throws ClassNotFoundException
* if the named type was not found
*/
private static Class<?> getClassFromSerializedName(
String serializedName, ClassLoader classLoader)
throws ClassNotFoundException {
Class<?> value = TYPE_NAMES.get(serializedName);
if (value != null) {
return value;
}
return Class.forName(serializedName, false, classLoader);
}
/**
* Returns the {@link java.lang.Class Class} for a primitive type
* given its corresponding wrapper {@link java.lang.Class Class}.
*
* @param wrapperClass
* primitive wrapper class
* @return primitive class
*/
private static Class<?> getPrimitiveClassFromWrapper(
Class<?> wrapperClass) {
return PRIMITIVE_WRAPPER_CLASS_TO_PRIMITIVE_CLASS
.get(wrapperClass);
}
/**
* Returns the source representation for a method signature.
*
* @param method
* method to get the source signature for
* @return source representation for a method signature
*/
private static String getSourceRepresentation(Method method) {
return method.toString().replace('$', '.');
}
/**
* Used to determine whether the specified interface name is
* implemented by the service class. This is done without loading the
* class (for security).
*/
private static boolean implementsInterface(Class<?> service,
String intfName) {
synchronized (serviceToImplementedInterfacesMap) {
// See if it's cached.
//
Set<String> interfaceSet = serviceToImplementedInterfacesMap
.get(service);
if (interfaceSet != null) {
if (interfaceSet.contains(intfName)) {
return true;
}
} else {
interfaceSet = new HashSet<String>();
serviceToImplementedInterfacesMap.put(service,
interfaceSet);
}
if (!service.isInterface()) {
while ((service != null)
&& !RemoteServiceServlet.class.equals(service)) {
Class<?>[] intfs = service.getInterfaces();
for (Class<?> intf : intfs) {
if (implementsInterfaceRecursive(intf, intfName)) {
interfaceSet.add(intfName);
return true;
}
}
// did not find the interface in this class so we look
// in the
// superclass
//
service = service.getSuperclass();
}
} else {
if (implementsInterfaceRecursive(service, intfName)) {
interfaceSet.add(intfName);
return true;
}
}
return false;
}
}
/**
* Only called from implementsInterface().
*/
private static boolean implementsInterfaceRecursive(Class<?> clazz,
String intfName) {
assert (clazz.isInterface());
if (clazz.getName().equals(intfName)) {
return true;
}
// search implemented interfaces
Class<?>[] intfs = clazz.getInterfaces();
for (Class<?> intf : intfs) {
if (implementsInterfaceRecursive(intf, intfName)) {
return true;
}
}
return false;
}
/**
* Returns true if the {@link java.lang.reflect.Method Method}
* definition on the service is specified to throw the exception
* contained in the InvocationTargetException or false otherwise. NOTE
* we do not check that the type is serializable here. We assume that
* it must be otherwise the application would never have been allowed
* to run.
*
* @param serviceIntfMethod
* the method from the RPC request
* @param cause
* the exception that the method threw
* @return true if the exception's type is in the method's signature
*/
private static boolean isExpectedException(Method serviceIntfMethod,
Throwable cause) {
assert (serviceIntfMethod != null);
assert (cause != null);
Class<?>[] exceptionsThrown = serviceIntfMethod
.getExceptionTypes();
if (exceptionsThrown.length <= 0) {
// The method is not specified to throw any exceptions
//
return false;
}
Class<? extends Throwable> causeType = cause.getClass();
for (Class<?> exceptionThrown : exceptionsThrown) {
assert (exceptionThrown != null);
if (exceptionThrown.isAssignableFrom(causeType)) {
return true;
}
}
return false;
}
/**
* Straight copy from
* {@link com.google.gwt.dev.util.TypeInfo#getSourceRepresentation(Class)}
* to avoid runtime dependency on gwt-dev.
*/
private static String printTypeName(Class<?> type) {
// Primitives
//
if (type.equals(Integer.TYPE)) {
return "int";
} else if (type.equals(Long.TYPE)) {
return "long";
} else if (type.equals(Short.TYPE)) {
return "short";
} else if (type.equals(Byte.TYPE)) {
return "byte";
} else if (type.equals(Character.TYPE)) {
return "char";
} else if (type.equals(Boolean.TYPE)) {
return "boolean";
} else if (type.equals(Float.TYPE)) {
return "float";
} else if (type.equals(Double.TYPE)) {
return "double";
}
// Arrays
//
if (type.isArray()) {
Class<?> componentType = type.getComponentType();
return printTypeName(componentType) + "[]";
}
// Everything else
//
return type.getName().replace('$', '.');
}
/**
* Static classes have no constructability.
*/
private RPC1524() {
// Not instantiable
}
}