private Expression createParameterUnmarshalExpressionForAnnotation(
Class<?> clazz, Method method, Class<?> parameterType, Annotation annotation) {
if (annotation instanceof AttachmentObjects) {
return ExpressionBuilder.attachmentObjectsExpression();
} else if (annotation instanceof Attachments) {
return ExpressionBuilder.attachmentsExpression();
} else if (annotation instanceof Property) {
Property propertyAnnotation = (Property) annotation;
return ExpressionBuilder.exchangePropertyExpression(propertyAnnotation.value());
} else if (annotation instanceof ExchangeProperty) {
ExchangeProperty propertyAnnotation = (ExchangeProperty) annotation;
return ExpressionBuilder.exchangePropertyExpression(propertyAnnotation.value());
} else if (annotation instanceof Properties) {
return ExpressionBuilder.propertiesExpression();
} else if (annotation instanceof Header) {
Header headerAnnotation = (Header) annotation;
return ExpressionBuilder.headerExpression(headerAnnotation.value());
} else if (annotation instanceof Headers) {
return ExpressionBuilder.headersExpression();
} else if (annotation instanceof OutHeaders) {
return ExpressionBuilder.outHeadersExpression();
} else if (annotation instanceof ExchangeException) {
return ExpressionBuilder.exchangeExceptionExpression(
CastUtils.cast(parameterType, Exception.class));
} else {
LanguageAnnotation languageAnnotation =
annotation.annotationType().getAnnotation(LanguageAnnotation.class);
if (languageAnnotation != null) {
Class<?> type = languageAnnotation.factory();
Object object = camelContext.getInjector().newInstance(type);
if (object instanceof AnnotationExpressionFactory) {
AnnotationExpressionFactory expressionFactory = (AnnotationExpressionFactory) object;
return expressionFactory.createExpression(
camelContext, annotation, languageAnnotation, parameterType);
} else {
LOG.warn(
"Ignoring bad annotation: "
+ languageAnnotation
+ "on method: "
+ method
+ " which declares a factory: "
+ type.getName()
+ " which does not implement "
+ AnnotationExpressionFactory.class.getName());
}
}
}
return null;
}
public static Expression header(String headerName) {
return ExpressionBuilder.headerExpression(headerName);
}
public SetHeaderDefinition(String headerName, String value) {
super(ExpressionBuilder.constantExpression(value));
setHeaderName(headerName);
}
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;
}
protected MethodInfo createMethodInfo(Class<?> clazz, Method method) {
Class<?>[] parameterTypes = method.getParameterTypes();
List<Annotation>[] parametersAnnotations = collectParameterAnnotations(clazz, method);
List<ParameterInfo> parameters = new ArrayList<ParameterInfo>();
List<ParameterInfo> bodyParameters = new ArrayList<ParameterInfo>();
boolean hasCustomAnnotation = false;
boolean hasHandlerAnnotation =
ObjectHelper.hasAnnotation(method.getAnnotations(), Handler.class);
int size = parameterTypes.length;
if (LOG.isTraceEnabled()) {
LOG.trace(
"Creating MethodInfo for class: {} method: {} having {} parameters",
new Object[] {clazz, method, size});
}
for (int i = 0; i < size; i++) {
Class<?> parameterType = parameterTypes[i];
Annotation[] parameterAnnotations =
parametersAnnotations[i].toArray(new Annotation[parametersAnnotations[i].size()]);
Expression expression =
createParameterUnmarshalExpression(clazz, method, parameterType, parameterAnnotations);
hasCustomAnnotation |= expression != null;
ParameterInfo parameterInfo =
new ParameterInfo(i, parameterType, parameterAnnotations, expression);
LOG.trace("Parameter #{}: {}", i, parameterInfo);
parameters.add(parameterInfo);
if (expression == null) {
boolean bodyAnnotation = ObjectHelper.hasAnnotation(parameterAnnotations, Body.class);
LOG.trace("Parameter #{} has @Body annotation", i);
hasCustomAnnotation |= bodyAnnotation;
if (bodyParameters.isEmpty()) {
// okay we have not yet set the body parameter and we have found
// the candidate now to use as body parameter
if (Exchange.class.isAssignableFrom(parameterType)) {
// use exchange
expression = ExpressionBuilder.exchangeExpression();
} else {
// assume it's the body and it must be mandatory convertible to the parameter type
// but we allow null bodies in case the message really contains a null body
expression = ExpressionBuilder.mandatoryBodyExpression(parameterType, true);
}
LOG.trace("Parameter #{} is the body parameter using expression {}", i, expression);
parameterInfo.setExpression(expression);
bodyParameters.add(parameterInfo);
} else {
// will ignore the expression for parameter evaluation
}
}
LOG.trace("Parameter #{} has parameter info: ", i, parameterInfo);
}
// now let's add the method to the repository
return new MethodInfo(
camelContext,
clazz,
method,
parameters,
bodyParameters,
hasCustomAnnotation,
hasHandlerAnnotation);
}
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;
}
