private MethodInfo chooseMethodWithMatchingParameters(
Exchange exchange, String parameters, Collection<MethodInfo> operationList)
throws AmbiguousMethodCallException {
// we have hardcoded parameters so need to match that with the given operations
Iterator<?> it = ObjectHelper.createIterator(parameters);
int count = 0;
while (it.hasNext()) {
it.next();
count++;
}
List<MethodInfo> operations = new ArrayList<MethodInfo>();
for (MethodInfo info : operationList) {
if (info.getParameters().size() == count) {
operations.add(info);
}
}
if (operations.isEmpty()) {
return null;
} else if (operations.size() == 1) {
return operations.get(0);
}
// okay we still got multiple operations, so need to match the best one
List<MethodInfo> candidates = new ArrayList<MethodInfo>();
for (MethodInfo info : operations) {
it = ObjectHelper.createIterator(parameters);
int index = 0;
boolean matches = true;
while (it.hasNext()) {
String parameter = (String) it.next();
Class<?> parameterType = BeanHelper.getValidParameterType(parameter);
Class<?> expectedType = info.getParameters().get(index).getType();
if (parameterType != null && expectedType != null) {
if (!parameterType.isAssignableFrom(expectedType)) {
matches = false;
break;
}
}
index++;
}
if (matches) {
candidates.add(info);
}
}
if (candidates.size() > 1) {
MethodInfo answer = getSingleCovariantMethod(candidates);
if (answer == null) {
throw new AmbiguousMethodCallException(exchange, candidates);
}
return answer;
}
return candidates.size() == 1 ? candidates.get(0) : null;
}
/**
* Returns true if this method is covariant with the specified method (this method may above or
* below the specified method in the class hierarchy)
*/
public boolean isCovariantWith(MethodInfo method) {
return method.getMethod().getName().equals(this.getMethod().getName())
&& (method.getMethod().getReturnType().isAssignableFrom(this.getMethod().getReturnType())
|| this.getMethod()
.getReturnType()
.isAssignableFrom(method.getMethod().getReturnType()))
&& Arrays.deepEquals(
method.getMethod().getParameterTypes(), this.getMethod().getParameterTypes());
}
private MethodInfo getSingleCovariantMethod(Collection<MethodInfo> candidates) {
// if all the candidates are actually covariant, it doesn't matter which one we call
MethodInfo firstCandidate = candidates.iterator().next();
for (MethodInfo candidate : candidates) {
if (!firstCandidate.isCovariantWith(candidate)) {
return null;
}
}
return firstCandidate;
}
private void removeNonMatchingMethods(List<MethodInfo> methods, String name) {
Iterator<MethodInfo> it = methods.iterator();
while (it.hasNext()) {
MethodInfo info = it.next();
if (!matchMethod(info.getMethod(), name)) {
// method does not match so remove it
it.remove();
}
}
}
/**
* Do we have a static method with the given name.
*
* <p>Shorthand method names for getters is supported, so you can pass in eg 'name' and Camel will
* can find the real 'getName' method instead.
*
* @param methodName the method name
* @return <tt>true</tt> if we have such a static method.
*/
public boolean hasStaticMethod(String methodName) {
List<MethodInfo> methods = getOperations(methodName);
if (methods == null || methods.isEmpty()) {
return false;
}
for (MethodInfo method : methods) {
if (method.isStaticMethod()) {
return true;
}
}
return false;
}
private MethodInfo chooseMethodWithMatchingBody(
Exchange exchange,
Collection<MethodInfo> operationList,
List<MethodInfo> operationsWithCustomAnnotation)
throws AmbiguousMethodCallException {
// see if we can find a method whose body param type matches the message body
Message in = exchange.getIn();
Object body = in.getBody();
if (body != null) {
Class<?> bodyType = body.getClass();
if (LOG.isTraceEnabled()) {
LOG.trace(
"Matching for method with a single parameter that matches type: {}",
bodyType.getCanonicalName());
}
List<MethodInfo> possibles = new ArrayList<MethodInfo>();
List<MethodInfo> possiblesWithException = new ArrayList<MethodInfo>();
for (MethodInfo methodInfo : operationList) {
// test for MEP pattern matching
boolean out = exchange.getPattern().isOutCapable();
if (out && methodInfo.isReturnTypeVoid()) {
// skip this method as the MEP is Out so the method must return something
continue;
}
// try to match the arguments
if (methodInfo.bodyParameterMatches(bodyType)) {
LOG.trace("Found a possible method: {}", methodInfo);
if (methodInfo.hasExceptionParameter()) {
// methods with accepts exceptions
possiblesWithException.add(methodInfo);
} else {
// regular methods with no exceptions
possibles.add(methodInfo);
}
}
}
// find best suited method to use
return chooseBestPossibleMethodInfo(
exchange,
operationList,
body,
possibles,
possiblesWithException,
operationsWithCustomAnnotation);
}
// no match so return null
return null;
}
private void removeAllAbstractMethods(List<MethodInfo> methods) {
Iterator<MethodInfo> it = methods.iterator();
while (it.hasNext()) {
MethodInfo info = it.next();
// if the class is an interface then keep the method
boolean isFromInterface =
Modifier.isInterface(info.getMethod().getDeclaringClass().getModifiers());
if (!isFromInterface && Modifier.isAbstract(info.getMethod().getModifiers())) {
// we cannot invoke an abstract method
it.remove();
}
}
}
private static void removeAllSetterOrGetterMethods(List<MethodInfo> methods) {
Iterator<MethodInfo> it = methods.iterator();
while (it.hasNext()) {
MethodInfo info = it.next();
if (IntrospectionSupport.isGetter(info.getMethod())) {
// skip getters
it.remove();
} else if (IntrospectionSupport.isSetter(info.getMethod())) {
// skip setters
it.remove();
}
}
}
/**
* Does the given method info override an existing method registered before (from a subclass)
*
* @param methodInfo the method to test
* @return the already registered method to use, null if not overriding any
*/
private MethodInfo overridesExistingMethod(MethodInfo methodInfo) {
for (MethodInfo info : methodMap.values()) {
Method source = info.getMethod();
Method target = methodInfo.getMethod();
boolean override = ObjectHelper.isOverridingMethod(source, target);
if (override) {
// same name, same parameters, then its overrides an existing class
return info;
}
}
return null;
}
/**
* Introspects the given method
*
* @param clazz the class
* @param method the method
* @return the method info, is newer <tt>null</tt>
*/
private MethodInfo introspect(Class<?> clazz, Method method) {
LOG.trace("Introspecting class: {}, method: {}", clazz, method);
String opName = method.getName();
MethodInfo methodInfo = createMethodInfo(clazz, method);
// methods already registered should be preferred to use instead of super classes of existing
// methods
// we want to us the method from the sub class over super classes, so if we have already
// registered
// the method then use it (we are traversing upwards: sub (child) -> super (farther) )
MethodInfo existingMethodInfo = overridesExistingMethod(methodInfo);
if (existingMethodInfo != null) {
LOG.trace(
"This method is already overridden in a subclass, so the method from the sub class is preferred: {}",
existingMethodInfo);
return existingMethodInfo;
}
LOG.trace("Adding operation: {} for method: {}", opName, methodInfo);
List<MethodInfo> existing = getOperations(opName);
if (existing != null) {
// we have an overloaded method so add the method info to the same key
existing.add(methodInfo);
} else {
// its a new method we have not seen before so wrap it in a list and add it
List<MethodInfo> methods = new ArrayList<MethodInfo>();
methods.add(methodInfo);
operations.put(opName, methods);
}
if (methodInfo.hasCustomAnnotation()) {
operationsWithCustomAnnotation.add(methodInfo);
} else if (methodInfo.hasBodyParameter()) {
operationsWithBody.add(methodInfo);
} else {
operationsWithNoBody.add(methodInfo);
}
if (methodInfo.hasHandlerAnnotation()) {
operationsWithHandlerAnnotation.add(methodInfo);
}
// must add to method map last otherwise we break stuff
methodMap.put(method, methodInfo);
return methodInfo;
}
private MethodInfo chooseMethodWithCustomAnnotations(
Exchange exchange, Collection<MethodInfo> possibles) throws AmbiguousMethodCallException {
// if we have only one method with custom annotations let's choose that
MethodInfo chosen = null;
for (MethodInfo possible : possibles) {
if (possible.hasCustomAnnotation()) {
if (chosen != null) {
chosen = null;
break;
} else {
chosen = possible;
}
}
}
return chosen;
}
private MethodInfo chooseBestPossibleMethodInfo(
Exchange exchange,
Collection<MethodInfo> operationList,
Object body,
List<MethodInfo> possibles,
List<MethodInfo> possiblesWithException,
List<MethodInfo> possibleWithCustomAnnotation)
throws AmbiguousMethodCallException {
Exception exception =
ExpressionBuilder.exchangeExceptionExpression().evaluate(exchange, Exception.class);
if (exception != null && possiblesWithException.size() == 1) {
LOG.trace(
"Exchange has exception set so we prefer method that also has exception as parameter");
// prefer the method that accepts exception in case we have an exception also
return possiblesWithException.get(0);
} else if (possibles.size() == 1) {
return possibles.get(0);
} else if (possibles.isEmpty()) {
LOG.trace("No possible methods so now trying to convert body to parameter types");
// let's try converting
Object newBody = null;
MethodInfo matched = null;
int matchCounter = 0;
for (MethodInfo methodInfo : operationList) {
if (methodInfo.getBodyParameterType() != null) {
if (methodInfo.getBodyParameterType().isInstance(body)) {
return methodInfo;
}
// we should only try to convert, as we are looking for best match
Object value =
exchange
.getContext()
.getTypeConverter()
.tryConvertTo(methodInfo.getBodyParameterType(), exchange, body);
if (value != null) {
if (LOG.isTraceEnabled()) {
LOG.trace(
"Converted body from: {} to: {}",
body.getClass().getCanonicalName(),
methodInfo.getBodyParameterType().getCanonicalName());
}
matchCounter++;
newBody = value;
matched = methodInfo;
}
}
}
if (matchCounter > 1) {
throw new AmbiguousMethodCallException(exchange, Arrays.asList(matched, matched));
}
if (matched != null) {
LOG.trace("Setting converted body: {}", body);
Message in = exchange.getIn();
in.setBody(newBody);
return matched;
}
} else {
// if we only have a single method with custom annotations, let's use that one
if (possibleWithCustomAnnotation.size() == 1) {
MethodInfo answer = possibleWithCustomAnnotation.get(0);
LOG.trace("There are only one method with annotations so we choose it: {}", answer);
return answer;
}
// try to choose among multiple methods with annotations
MethodInfo chosen = chooseMethodWithCustomAnnotations(exchange, possibles);
if (chosen != null) {
return chosen;
}
// just make sure the methods aren't all actually the same
chosen = getSingleCovariantMethod(possibles);
if (chosen != null) {
return chosen;
}
throw new AmbiguousMethodCallException(exchange, possibles);
}
// cannot find a good method to use
return null;
}
private MethodInfo chooseMethodWithMatchingParameters(
Exchange exchange, String parameters, Collection<MethodInfo> operationList)
throws AmbiguousMethodCallException {
// we have hardcoded parameters so need to match that with the given operations
Iterator<?> it = ObjectHelper.createIterator(parameters);
int count = 0;
while (it.hasNext()) {
it.next();
count++;
}
List<MethodInfo> operations = new ArrayList<MethodInfo>();
for (MethodInfo info : operationList) {
if (info.getParameters().size() == count) {
operations.add(info);
}
}
if (operations.isEmpty()) {
return null;
} else if (operations.size() == 1) {
return operations.get(0);
}
// okay we still got multiple operations, so need to match the best one
List<MethodInfo> candidates = new ArrayList<MethodInfo>();
MethodInfo fallbackCandidate = null;
for (MethodInfo info : operations) {
it = ObjectHelper.createIterator(parameters, ",", false);
int index = 0;
boolean matches = true;
while (it.hasNext()) {
String parameter = (String) it.next();
if (parameter != null) {
// must trim
parameter = parameter.trim();
}
Class<?> parameterType = BeanHelper.getValidParameterType(parameter);
Class<?> expectedType = info.getParameters().get(index).getType();
if (parameterType != null && expectedType != null) {
// if its a simple language then we need to evaluate the expression
// so we have the result and can find out what type the parameter actually is
if (StringHelper.hasStartToken(parameter, "simple")) {
LOG.trace(
"Evaluating simple expression for parameter #{}: {} to determine the class type of the parameter",
index,
parameter);
Object out =
getCamelContext()
.resolveLanguage("simple")
.createExpression(parameter)
.evaluate(exchange, Object.class);
if (out != null) {
parameterType = out.getClass();
}
}
// skip java.lang.Object type, when we have multiple possible methods we want to avoid it
// if possible
if (Object.class.equals(expectedType)) {
fallbackCandidate = info;
matches = false;
break;
}
boolean matchingTypes = isParameterMatchingType(parameterType, expectedType);
if (!matchingTypes) {
matches = false;
break;
}
}
index++;
}
if (matches) {
candidates.add(info);
}
}
if (candidates.size() > 1) {
MethodInfo answer = getSingleCovariantMethod(candidates);
if (answer != null) {
return answer;
}
}
return candidates.size() == 1 ? candidates.get(0) : fallbackCandidate;
}
private MethodInvocation createInvocation(Object pojo, Exchange exchange, Method explicitMethod)
throws AmbiguousMethodCallException, MethodNotFoundException {
MethodInfo methodInfo = null;
// find the explicit method to invoke
if (explicitMethod != null) {
for (List<MethodInfo> infos : operations.values()) {
for (MethodInfo info : infos) {
if (explicitMethod.equals(info.getMethod())) {
return info.createMethodInvocation(pojo, exchange);
}
}
}
throw new MethodNotFoundException(exchange, pojo, explicitMethod.getName());
}
String methodName = exchange.getIn().getHeader(Exchange.BEAN_METHOD_NAME, String.class);
if (methodName != null) {
// do not use qualifier for name
String name = methodName;
if (methodName.contains("(")) {
name = ObjectHelper.before(methodName, "(");
// the must be a ending parenthesis
if (!methodName.endsWith(")")) {
throw new IllegalArgumentException(
"Method should end with parenthesis, was " + methodName);
}
}
boolean emptyParameters = methodName.endsWith("()");
// special for getClass, as we want the user to be able to invoke this method
// for example to log the class type or the likes
if ("class".equals(name) || "getClass".equals(name)) {
try {
Method method = pojo.getClass().getMethod("getClass");
methodInfo =
new MethodInfo(
exchange.getContext(),
pojo.getClass(),
method,
Collections.<ParameterInfo>emptyList(),
Collections.<ParameterInfo>emptyList(),
false,
false);
} catch (NoSuchMethodException e) {
throw new MethodNotFoundException(exchange, pojo, "getClass");
}
// special for length on an array type
} else if ("length".equals(name) && pojo.getClass().isArray()) {
try {
// need to use arrayLength method from ObjectHelper as Camel's bean OGNL support is method
// invocation based
// and not for accessing fields. And hence we need to create a MethodInfo instance with a
// method to call
// and therefore use arrayLength from ObjectHelper to return the array length field.
Method method = ObjectHelper.class.getMethod("arrayLength", Object[].class);
ParameterInfo pi =
new ParameterInfo(
0,
Object[].class,
null,
ExpressionBuilder.mandatoryBodyExpression(Object[].class, true));
List<ParameterInfo> lpi = new ArrayList<ParameterInfo>(1);
lpi.add(pi);
methodInfo =
new MethodInfo(
exchange.getContext(), pojo.getClass(), method, lpi, lpi, false, false);
// Need to update the message body to be pojo for the invocation
exchange.getIn().setBody(pojo);
} catch (NoSuchMethodException e) {
throw new MethodNotFoundException(exchange, pojo, "getClass");
}
} else {
List<MethodInfo> methods = getOperations(name);
if (methods != null && methods.size() == 1) {
// only one method then choose it
methodInfo = methods.get(0);
// validate that if we want an explicit no-arg method, then that's what we get
if (emptyParameters && methodInfo.hasParameters()) {
throw new MethodNotFoundException(exchange, pojo, methodName, "(with no parameters)");
}
} else if (methods != null) {
// there are more methods with that name so we cannot decide which to use
// but first let's try to choose a method and see if that complies with the name
// must use the method name which may have qualifiers
methodInfo = chooseMethod(pojo, exchange, methodName);
// validate that if we want an explicit no-arg method, then that's what we get
if (emptyParameters) {
if (methodInfo == null || methodInfo.hasParameters()) {
// we could not find a no-arg method with that name
throw new MethodNotFoundException(exchange, pojo, methodName, "(with no parameters)");
}
}
if (methodInfo == null
|| (name != null && !name.equals(methodInfo.getMethod().getName()))) {
throw new AmbiguousMethodCallException(exchange, methods);
}
} else {
// a specific method was given to invoke but not found
throw new MethodNotFoundException(exchange, pojo, methodName);
}
}
}
if (methodInfo == null) {
// no name or type
methodInfo = chooseMethod(pojo, exchange, null);
}
if (methodInfo == null) {
methodInfo = defaultMethod;
}
if (methodInfo != null) {
LOG.trace("Chosen method to invoke: {} on bean: {}", methodInfo, pojo);
return methodInfo.createMethodInvocation(pojo, exchange);
}
LOG.debug("Cannot find suitable method to invoke on bean: {}", pojo);
return null;
}
