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The Core Camel Java DSL based router
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.camel.component.bean;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.camel.AttachmentObjects;
import org.apache.camel.Attachments;
import org.apache.camel.Body;
import org.apache.camel.CamelContext;
import org.apache.camel.Exchange;
import org.apache.camel.ExchangeException;
import org.apache.camel.ExchangeProperties;
import org.apache.camel.ExchangeProperty;
import org.apache.camel.Expression;
import org.apache.camel.Handler;
import org.apache.camel.Header;
import org.apache.camel.Headers;
import org.apache.camel.Message;
import org.apache.camel.OutHeaders;
import org.apache.camel.Properties;
import org.apache.camel.Property;
import org.apache.camel.PropertyInject;
import org.apache.camel.builder.ExpressionBuilder;
import org.apache.camel.language.LanguageAnnotation;
import org.apache.camel.spi.Registry;
import org.apache.camel.util.CastUtils;
import org.apache.camel.util.IntrospectionSupport;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.StringHelper;
import org.apache.camel.util.StringQuoteHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Represents the metadata about a bean type created via a combination of
* introspection and annotations together with some useful sensible defaults
*/
public class BeanInfo {
private static final Logger LOG = LoggerFactory.getLogger(BeanInfo.class);
private static final String CGLIB_CLASS_SEPARATOR = "$$";
private static final List EXCLUDED_METHODS = new ArrayList();
private final CamelContext camelContext;
private final BeanComponent component;
private final Class type;
private final ParameterMappingStrategy strategy;
private final MethodInfo defaultMethod;
// shared state with details of operations introspected from the bean, created during the constructor
private Map> operations = new HashMap>();
private List operationsWithBody = new ArrayList();
private List operationsWithNoBody = new ArrayList();
private List operationsWithCustomAnnotation = new ArrayList();
private List operationsWithHandlerAnnotation = new ArrayList();
private Map methodMap = new HashMap();
private boolean publicConstructors;
static {
// exclude all java.lang.Object methods as we dont want to invoke them
EXCLUDED_METHODS.addAll(Arrays.asList(Object.class.getMethods()));
// exclude all java.lang.reflect.Proxy methods as we dont want to invoke them
EXCLUDED_METHODS.addAll(Arrays.asList(Proxy.class.getMethods()));
try {
// but keep toString as this method is okay
EXCLUDED_METHODS.remove(Object.class.getMethod("toString"));
EXCLUDED_METHODS.remove(Proxy.class.getMethod("toString"));
} catch (Throwable e) {
// ignore
}
}
public BeanInfo(CamelContext camelContext, Class type) {
this(camelContext, type, createParameterMappingStrategy(camelContext));
}
public BeanInfo(CamelContext camelContext, Method explicitMethod) {
this(camelContext, explicitMethod.getDeclaringClass(), explicitMethod, createParameterMappingStrategy(camelContext));
}
public BeanInfo(CamelContext camelContext, Class type, ParameterMappingStrategy strategy) {
this(camelContext, type, null, strategy);
}
public BeanInfo(CamelContext camelContext, Class type, Method explicitMethod, ParameterMappingStrategy strategy) {
this.camelContext = camelContext;
this.type = type;
this.strategy = strategy;
this.component = camelContext.getComponent("bean", BeanComponent.class);
final BeanInfoCacheKey key = new BeanInfoCacheKey(type, explicitMethod);
// lookup if we have a bean info cache
BeanInfo beanInfo = component.getBeanInfoFromCache(key);
if (beanInfo != null) {
// copy the values from the cache we need
defaultMethod = beanInfo.defaultMethod;
operations = beanInfo.operations;
operationsWithBody = beanInfo.operationsWithBody;
operationsWithNoBody = beanInfo.operationsWithNoBody;
operationsWithCustomAnnotation = beanInfo.operationsWithCustomAnnotation;
operationsWithHandlerAnnotation = beanInfo.operationsWithHandlerAnnotation;
methodMap = beanInfo.methodMap;
publicConstructors = beanInfo.publicConstructors;
return;
}
if (explicitMethod != null) {
// must be a valid method
if (!isValidMethod(type, explicitMethod)) {
throw new IllegalArgumentException("The method " + explicitMethod + " is not valid (for example the method must be public)");
}
introspect(getType(), explicitMethod);
} else {
introspect(getType());
}
// if there are only 1 method with 1 operation then select it as a default/fallback method
MethodInfo method = null;
if (operations.size() == 1) {
List methods = operations.values().iterator().next();
if (methods.size() == 1) {
method = methods.get(0);
}
}
defaultMethod = method;
// mark the operations lists as unmodifiable, as they should not change during runtime
// to keep this code thread safe
operations = Collections.unmodifiableMap(operations);
operationsWithBody = Collections.unmodifiableList(operationsWithBody);
operationsWithNoBody = Collections.unmodifiableList(operationsWithNoBody);
operationsWithCustomAnnotation = Collections.unmodifiableList(operationsWithCustomAnnotation);
operationsWithHandlerAnnotation = Collections.unmodifiableList(operationsWithHandlerAnnotation);
methodMap = Collections.unmodifiableMap(methodMap);
// add new bean info to cache
component.addBeanInfoToCache(key, this);
}
public Class getType() {
return type;
}
public CamelContext getCamelContext() {
return camelContext;
}
public static ParameterMappingStrategy createParameterMappingStrategy(CamelContext camelContext) {
// lookup in registry first if there is a user define strategy
Registry registry = camelContext.getRegistry();
ParameterMappingStrategy answer = registry.lookupByNameAndType(BeanConstants.BEAN_PARAMETER_MAPPING_STRATEGY, ParameterMappingStrategy.class);
if (answer == null) {
// no then use the default one
answer = new DefaultParameterMappingStrategy();
}
return answer;
}
public MethodInvocation createInvocation(Object pojo, Exchange exchange)
throws AmbiguousMethodCallException, MethodNotFoundException {
return createInvocation(pojo, exchange, null);
}
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 infos : operations.values()) {
for (MethodInfo info : infos) {
if (explicitMethod.equals(info.getMethod())) {
return info.createMethodInvocation(pojo, info.hasParameters(), 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 = StringHelper.before(methodName, "(");
// the must be a ending parenthesis
if (!methodName.endsWith(")")) {
throw new IllegalArgumentException("Method should end with parenthesis, was " + methodName);
}
// and there must be an even number of parenthesis in the syntax
// (we can use betweenOuterPair as it return null if the syntax is invalid)
if (StringHelper.betweenOuterPair(methodName, '(', ')') == null) {
throw new IllegalArgumentException("Method should have even pair of 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.emptyList(), Collections.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 lpi = new ArrayList(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 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 && methodMap.size() >= 2) {
// only try to choose if there is at least 2 methods
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, methodInfo.hasParameters(), exchange);
}
LOG.debug("Cannot find suitable method to invoke on bean: {}", pojo);
return null;
}
/**
* Introspects the given class
*
* @param clazz the class
*/
private void introspect(Class clazz) {
// does the class have any public constructors?
publicConstructors = clazz.getConstructors().length > 0;
MethodsFilter methods = new MethodsFilter(getType());
introspect(clazz, methods);
// now introspect the methods and filter non valid methods
for (Method method : methods.asReadOnlyList()) {
boolean valid = isValidMethod(clazz, method);
LOG.trace("Method: {} is valid: {}", method, valid);
if (valid) {
introspect(clazz, method);
}
}
}
private void introspect(Class clazz, MethodsFilter filteredMethods) {
// get the target clazz as it could potentially have been enhanced by
// CGLIB etc.
clazz = getTargetClass(clazz);
ObjectHelper.notNull(clazz, "clazz", this);
LOG.trace("Introspecting class: {}", clazz);
for (Method m : Arrays.asList(clazz.getDeclaredMethods())) {
filteredMethods.filterMethod(m);
}
Class superClass = clazz.getSuperclass();
if (superClass != null && !superClass.equals(Object.class)) {
introspect(superClass, filteredMethods);
}
for (Class superInterface : clazz.getInterfaces()) {
introspect(superInterface, filteredMethods);
}
}
/**
* Introspects the given method
*
* @param clazz the class
* @param method the method
* @return the method info, is newer null
*/
private MethodInfo introspect(Class clazz, Method method) {
LOG.trace("Introspecting class: {}, method: {}", clazz, method);
String opName = method.getName();
MethodInfo methodInfo = createMethodInfo(clazz, method);
// Foster the use of a potentially already registered most specific override
MethodInfo existingMethodInfo = findMostSpecificOverride(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 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 methods = new ArrayList();
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;
}
/**
* Returns the {@link MethodInfo} for the given method if it exists or null
* if there is no metadata available for the given method
*/
public MethodInfo getMethodInfo(Method method) {
MethodInfo answer = methodMap.get(method);
if (answer == null) {
// maybe the method overrides, and the method map keeps info of the source override we can use
for (Map.Entry methodEntry : methodMap.entrySet()) {
Method source = methodEntry.getKey();
if (ObjectHelper.isOverridingMethod(getType(), source, method, false)) {
answer = methodEntry.getValue();
break;
}
}
}
if (answer == null) {
// maybe the method is defined on a base class?
if (type != Object.class) {
Class superclass = type.getSuperclass();
if (superclass != null && superclass != Object.class) {
BeanInfo superBeanInfo = new BeanInfo(camelContext, superclass, strategy);
return superBeanInfo.getMethodInfo(method);
}
}
}
return answer;
}
protected MethodInfo createMethodInfo(Class clazz, Method method) {
Class[] parameterTypes = method.getParameterTypes();
List[] parametersAnnotations = collectParameterAnnotations(clazz, method);
List parameters = new ArrayList();
List bodyParameters = new ArrayList();
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);
}
@SuppressWarnings("unchecked")
protected List[] collectParameterAnnotations(Class c, Method m) {
List[] annotations = new List[m.getParameterCount()];
for (int i = 0; i < annotations.length; i++) {
annotations[i] = new ArrayList();
}
collectParameterAnnotations(c, m, annotations);
return annotations;
}
protected void collectParameterAnnotations(Class c, Method m, List[] a) {
try {
Annotation[][] pa = c.getDeclaredMethod(m.getName(), m.getParameterTypes()).getParameterAnnotations();
for (int i = 0; i < pa.length; i++) {
a[i].addAll(Arrays.asList(pa[i]));
}
} catch (NoSuchMethodException e) {
// no method with signature of m declared on c
}
for (Class i : c.getInterfaces()) {
collectParameterAnnotations(i, m, a);
}
if (!c.isInterface() && c.getSuperclass() != null) {
collectParameterAnnotations(c.getSuperclass(), m, a);
}
}
/**
* Choose one of the available methods to invoke if we can match
* the message body to the body parameter
*
* @param pojo the bean to invoke a method on
* @param exchange the message exchange
* @param name an optional name of the method that must match, use null to indicate all methods
* @return the method to invoke or null if no definitive method could be matched
* @throws AmbiguousMethodCallException is thrown if cannot choose method due to ambiguity
*/
protected MethodInfo chooseMethod(Object pojo, Exchange exchange, String name) throws AmbiguousMethodCallException {
// @Handler should be select first
// then any single method that has a custom @annotation
// or any single method that has a match parameter type that matches the Exchange payload
// and last then try to select the best among the rest
// must use defensive copy, to avoid altering the shared lists
// and we want to remove unwanted operations from these local lists
List localOperationsWithBody = null;
if (!operationsWithBody.isEmpty()) {
localOperationsWithBody = new ArrayList<>(operationsWithBody);
}
List localOperationsWithNoBody = null;
if (!operationsWithNoBody.isEmpty()) {
localOperationsWithNoBody = new ArrayList<>(operationsWithNoBody);
}
List localOperationsWithCustomAnnotation = null;
if (!operationsWithCustomAnnotation.isEmpty()) {
localOperationsWithCustomAnnotation = new ArrayList<>(operationsWithCustomAnnotation);
}
List localOperationsWithHandlerAnnotation = null;
if (!operationsWithHandlerAnnotation.isEmpty()) {
localOperationsWithHandlerAnnotation = new ArrayList<>(operationsWithHandlerAnnotation);
}
// remove all abstract methods
if (localOperationsWithBody != null) {
removeAllAbstractMethods(localOperationsWithBody);
}
if (localOperationsWithNoBody != null) {
removeAllAbstractMethods(localOperationsWithNoBody);
}
if (localOperationsWithCustomAnnotation != null) {
removeAllAbstractMethods(localOperationsWithCustomAnnotation);
}
if (localOperationsWithHandlerAnnotation != null) {
removeAllAbstractMethods(localOperationsWithHandlerAnnotation);
}
if (name != null) {
// filter all lists to only include methods with this name
if (localOperationsWithHandlerAnnotation != null) {
removeNonMatchingMethods(localOperationsWithHandlerAnnotation, name);
}
if (localOperationsWithCustomAnnotation != null) {
removeNonMatchingMethods(localOperationsWithCustomAnnotation, name);
}
if (localOperationsWithBody != null) {
removeNonMatchingMethods(localOperationsWithBody, name);
}
if (localOperationsWithNoBody != null) {
removeNonMatchingMethods(localOperationsWithNoBody, name);
}
} else {
// remove all getter/setter as we do not want to consider these methods
if (localOperationsWithHandlerAnnotation != null) {
removeAllSetterOrGetterMethods(localOperationsWithHandlerAnnotation);
}
if (localOperationsWithCustomAnnotation != null) {
removeAllSetterOrGetterMethods(localOperationsWithCustomAnnotation);
}
if (localOperationsWithBody != null) {
removeAllSetterOrGetterMethods(localOperationsWithBody);
}
if (localOperationsWithNoBody != null) {
removeAllSetterOrGetterMethods(localOperationsWithNoBody);
}
}
if (localOperationsWithHandlerAnnotation != null && localOperationsWithHandlerAnnotation.size() > 1) {
// if we have more than 1 @Handler then its ambiguous
throw new AmbiguousMethodCallException(exchange, localOperationsWithHandlerAnnotation);
}
if (localOperationsWithHandlerAnnotation != null && localOperationsWithHandlerAnnotation.size() == 1) {
// methods with handler should be preferred
return localOperationsWithHandlerAnnotation.get(0);
} else if (localOperationsWithCustomAnnotation != null && localOperationsWithCustomAnnotation.size() == 1) {
// if there is one method with an annotation then use that one
return localOperationsWithCustomAnnotation.get(0);
}
// named method and with no parameters
boolean noParameters = name != null && name.endsWith("()");
if (noParameters && localOperationsWithNoBody != null && localOperationsWithNoBody.size() == 1) {
// if there was a method name configured and it has no parameters, then use the method with no body (eg no parameters)
return localOperationsWithNoBody.get(0);
} else if (!noParameters && (localOperationsWithBody != null && localOperationsWithBody.size() == 1 && localOperationsWithCustomAnnotation == null)) {
// if there is one method with body then use that one
return localOperationsWithBody.get(0);
}
if (localOperationsWithBody != null || localOperationsWithCustomAnnotation != null) {
Collection possibleOperations = new ArrayList<>();
if (localOperationsWithBody != null) {
possibleOperations.addAll(localOperationsWithBody);
}
if (localOperationsWithCustomAnnotation != null) {
possibleOperations.addAll(localOperationsWithCustomAnnotation);
}
if (!possibleOperations.isEmpty()) {
MethodInfo answer = null;
if (name != null) {
// do we have hardcoded parameters values provided from the method name then use that for matching
String parameters = StringHelper.between(name, "(", ")");
if (parameters != null) {
// special as we have hardcoded parameters, so we need to choose method that matches those parameters the best
LOG.trace("Choosing best matching method matching parameters: {}", parameters);
answer = chooseMethodWithMatchingParameters(exchange, parameters, possibleOperations);
}
}
if (answer == null) {
// multiple possible operations so find the best suited if possible
answer = chooseMethodWithMatchingBody(exchange, possibleOperations, localOperationsWithCustomAnnotation);
}
if (answer == null && possibleOperations.size() > 1) {
answer = getSingleCovariantMethod(possibleOperations);
}
if (answer == null) {
throw new AmbiguousMethodCallException(exchange, possibleOperations);
} else {
return answer;
}
}
}
// not possible to determine
return null;
}
private MethodInfo chooseMethodWithMatchingParameters(Exchange exchange, String parameters, Collection 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 operations = new ArrayList();
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 candidates = new ArrayList();
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 boolean isParameterMatchingType(Class parameterType, Class expectedType) {
if (Number.class.equals(parameterType)) {
// number should match long/int/etc.
if (Integer.class.isAssignableFrom(expectedType) || Long.class.isAssignableFrom(expectedType)
|| int.class.isAssignableFrom(expectedType) || long.class.isAssignableFrom(expectedType)) {
return true;
}
}
return parameterType.isAssignableFrom(expectedType);
}
private MethodInfo getSingleCovariantMethod(Collection 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 MethodInfo chooseMethodWithMatchingBody(Exchange exchange, Collection operationList,
List 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 possibles = new ArrayList<>();
List possiblesWithException = null;
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
if (possiblesWithException == null) {
possiblesWithException = new ArrayList<>();
}
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 MethodInfo chooseBestPossibleMethodInfo(Exchange exchange, Collection operationList, Object body,
List possibles, List possiblesWithException,
List possibleWithCustomAnnotation)
throws AmbiguousMethodCallException {
Exception exception = ExpressionBuilder.exchangeExceptionExpression().evaluate(exchange, Exception.class);
if (exception != null && possiblesWithException != 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 != null && 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(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;
}
/**
* Validates whether the given method is a valid candidate for Camel Bean Binding.
*
* @param clazz the class
* @param method the method
* @return true if valid, false to skip the method
*/
protected boolean isValidMethod(Class clazz, Method method) {
// must not be in the excluded list
for (Method excluded : EXCLUDED_METHODS) {
if (ObjectHelper.isOverridingMethod(excluded, method)) {
// the method is overriding an excluded method so its not valid
return false;
}
}
// must be a public method
if (!Modifier.isPublic(method.getModifiers())) {
return false;
}
// return type must not be an Exchange and it should not be a bridge method
if ((method.getReturnType() != null && Exchange.class.isAssignableFrom(method.getReturnType())) || method.isBridge()) {
return false;
}
return true;
}
/**
* Gets the most specific override of a given method, if any. Indeed,
* overrides may have already been found while inspecting sub classes. Or
* the given method could override an interface extra method.
*
* @param proposedMethodInfo the method for which a more specific override is
* searched
* @return The already registered most specific override if any, otherwise
* null
*/
private MethodInfo findMostSpecificOverride(MethodInfo proposedMethodInfo) {
for (MethodInfo alreadyRegisteredMethodInfo : methodMap.values()) {
Method alreadyRegisteredMethod = alreadyRegisteredMethodInfo.getMethod();
Method proposedMethod = proposedMethodInfo.getMethod();
if (ObjectHelper.isOverridingMethod(getType(), proposedMethod, alreadyRegisteredMethod, false)) {
return alreadyRegisteredMethodInfo;
} else if (ObjectHelper.isOverridingMethod(getType(), alreadyRegisteredMethod, proposedMethod, false)) {
return proposedMethodInfo;
}
}
return null;
}
private MethodInfo chooseMethodWithCustomAnnotations(Collection possibles) {
// 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;
}
/**
* Creates an expression for the given parameter type if the parameter can
* be mapped automatically or null if the parameter cannot be mapped due to
* insufficient annotations or not fitting with the default type
* conventions.
*/
private Expression createParameterUnmarshalExpression(Class clazz, Method method,
Class parameterType, Annotation[] parameterAnnotation) {
// look for a parameter annotation that converts into an expression
for (Annotation annotation : parameterAnnotation) {
Expression answer = createParameterUnmarshalExpressionForAnnotation(clazz, method, parameterType, annotation);
if (answer != null) {
return answer;
}
}
// no annotations then try the default parameter mappings
return strategy.getDefaultParameterTypeExpression(parameterType);
}
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.exchangePropertiesExpression();
} else if (annotation instanceof ExchangeProperties) {
return ExpressionBuilder.exchangePropertiesExpression();
} 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 if (annotation instanceof PropertyInject) {
PropertyInject propertyAnnotation = (PropertyInject) annotation;
Expression inject = ExpressionBuilder.propertiesComponentExpression(propertyAnnotation.value(), null, propertyAnnotation.defaultValue());
return ExpressionBuilder.convertToExpression(inject, parameterType);
} 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;
}
private static void removeAllSetterOrGetterMethods(List methods) {
Iterator 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();
}
}
}
private void removeNonMatchingMethods(List methods, String name) {
// method does not match so remove it
methods.removeIf(info -> !matchMethod(info.getMethod(), name));
}
private void removeAllAbstractMethods(List methods) {
Iterator 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 boolean matchMethod(Method method, String methodName) {
if (methodName == null) {
return true;
}
if (methodName.contains("(") && !methodName.endsWith(")")) {
throw new IllegalArgumentException("Name must have both starting and ending parenthesis, was: " + methodName);
}
// do not use qualifier for name matching
String name = methodName;
if (name.contains("(")) {
name = StringHelper.before(name, "(");
}
// must match name
if (name != null && !name.equals(method.getName())) {
return false;
}
// is it a method with no parameters
boolean noParameters = methodName.endsWith("()");
if (noParameters) {
return method.getParameterCount() == 0;
}
// match qualifier types which is used to select among overloaded methods
String types = StringHelper.between(methodName, "(", ")");
if (ObjectHelper.isNotEmpty(types)) {
// we must qualify based on types to match method
String[] parameters = StringQuoteHelper.splitSafeQuote(types, ',');
Class[] parameterTypes = null;
Iterator it = ObjectHelper.createIterator(parameters);
for (int i = 0; i < method.getParameterCount(); i++) {
if (it.hasNext()) {
if (parameterTypes == null) {
parameterTypes = method.getParameterTypes();
}
Class parameterType = parameterTypes[i];
String qualifyType = (String) it.next();
if (ObjectHelper.isEmpty(qualifyType)) {
continue;
}
// trim the type
qualifyType = qualifyType.trim();
if ("*".equals(qualifyType)) {
// * is a wildcard so we accept and match that parameter type
continue;
}
if (BeanHelper.isValidParameterValue(qualifyType)) {
// its a parameter value, so continue to next parameter
// as we should only check for FQN/type parameters
continue;
}
// if qualify type indeed is a class, then it must be assignable with the parameter type
Boolean assignable = BeanHelper.isAssignableToExpectedType(getCamelContext().getClassResolver(), qualifyType, parameterType);
// the method will return null if the qualifyType is not a class
if (assignable != null && !assignable) {
return false;
}
} else {
// there method has more parameters than was specified in the method name qualifiers
return false;
}
}
// if the method has no more types then we can only regard it as matched
// if there are no more qualifiers
if (it.hasNext()) {
return false;
}
}
// the method matched
return true;
}
private static Class getTargetClass(Class clazz) {
if (clazz != null && clazz.getName().contains(CGLIB_CLASS_SEPARATOR)) {
Class superClass = clazz.getSuperclass();
if (superClass != null && !Object.class.equals(superClass)) {
return superClass;
}
}
return clazz;
}
/**
* Do we have a method with the given name.
*
* 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 true if we have such a method.
*/
public boolean hasMethod(String methodName) {
return getOperations(methodName) != null;
}
/**
* Do we have a static method with the given name.
*
* 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 true if we have such a static method.
*/
public boolean hasStaticMethod(String methodName) {
List methods = getOperations(methodName);
if (methods == null || methods.isEmpty()) {
return false;
}
for (MethodInfo method : methods) {
if (method.isStaticMethod()) {
return true;
}
}
return false;
}
/**
* Returns whether the bean class has any public constructors.
*/
public boolean hasPublicConstructors() {
return publicConstructors;
}
/**
* Gets the list of methods sorted by A..Z method name.
*
* @return the methods.
*/
public List getMethods() {
if (operations.isEmpty()) {
return Collections.emptyList();
}
List methods = new ArrayList();
for (Collection col : operations.values()) {
methods.addAll(col);
}
if (methods.size() > 1) {
// sort the methods by name A..Z
methods.sort(Comparator.comparing(o -> o.getMethod().getName()));
}
return methods;
}
/**
* Does any of the methods have a Canel @Handler annotation.
*/
public boolean hasAnyMethodHandlerAnnotation() {
return !operationsWithHandlerAnnotation.isEmpty();
}
/**
* Get the operation(s) with the given name. We can have multiple when methods is overloaded.
*
* 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 the found method, or null if not found
*/
private List getOperations(String methodName) {
// do not use qualifier for name
if (methodName.contains("(")) {
methodName = StringHelper.before(methodName, "(");
}
List answer = operations.get(methodName);
if (answer != null) {
return answer;
}
// now try all getters to see if any of those matched the methodName
for (Method method : methodMap.keySet()) {
if (IntrospectionSupport.isGetter(method)) {
String shorthandMethodName = IntrospectionSupport.getGetterShorthandName(method);
// if the two names matches then see if we can find it using that name
if (methodName != null && methodName.equals(shorthandMethodName)) {
return operations.get(method.getName());
}
}
}
return null;
}
}