ca.uhn.fhir.util.ReflectionUtil Maven / Gradle / Ivy
/*
* #%L
* HAPI FHIR - Core Library
* %%
* Copyright (C) 2014 - 2024 Smile CDR, 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.
* #L%
*/
package ca.uhn.fhir.util;
import ca.uhn.fhir.context.ConfigurationException;
import ca.uhn.fhir.i18n.Msg;
import ca.uhn.fhir.rest.server.exceptions.InternalErrorException;
import jakarta.annotation.Nonnull;
import org.apache.commons.lang3.Validate;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
public class ReflectionUtil {
public static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
public static final Class[] EMPTY_CLASS_ARRAY = new Class[0];
private static final ConcurrentHashMap ourFhirServerVersions = new ConcurrentHashMap<>();
private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(ReflectionUtil.class);
/**
* Non instantiable
*/
private ReflectionUtil() {
super();
}
/**
* Returns all methods declared against {@literal theClazz}. This method returns a predictable order, which is
* sorted by method name and then by parameters.
*
* This method does not include superclass methods (see {@link #getDeclaredMethods(Class, boolean)} if you
* want to include those.
*
*/
public static List getDeclaredMethods(Class theClazz) {
return getDeclaredMethods(theClazz, false);
}
/**
* Returns all methods declared against {@literal theClazz}. This method returns a predictable order, which is
* sorted by method name and then by parameters.
*/
public static List getDeclaredMethods(Class theClazz, boolean theIncludeMethodsFromSuperclasses) {
HashMap foundMethods = new HashMap<>();
populateDeclaredMethodsMap(theClazz, foundMethods, theIncludeMethodsFromSuperclasses);
List retVal = new ArrayList<>(foundMethods.values());
retVal.sort((Comparator.comparing(ReflectionUtil::describeMethodInSortFriendlyWay)));
return retVal;
}
private static void populateDeclaredMethodsMap(
Class theClazz, HashMap foundMethods, boolean theIncludeMethodsFromSuperclasses) {
Method[] declaredMethods = theClazz.getDeclaredMethods();
for (Method next : declaredMethods) {
if (Modifier.isAbstract(next.getModifiers())
|| Modifier.isStatic(next.getModifiers())
|| Modifier.isPrivate(next.getModifiers())) {
continue;
}
String description = next.getName() + Arrays.asList(next.getParameterTypes());
if (!foundMethods.containsKey(description)) {
try {
Method method = theClazz.getMethod(next.getName(), next.getParameterTypes());
foundMethods.put(description, method);
} catch (NoSuchMethodException | SecurityException e) {
foundMethods.put(description, next);
}
}
}
if (theIncludeMethodsFromSuperclasses && !theClazz.getSuperclass().equals(Object.class)) {
populateDeclaredMethodsMap(theClazz.getSuperclass(), foundMethods, theIncludeMethodsFromSuperclasses);
}
}
/**
* Returns a description like startsWith params(java.lang.String, int) returns(boolean).
* The format is chosen in order to provide a predictable and useful sorting order.
*/
public static String describeMethodInSortFriendlyWay(Method theMethod) {
StringBuilder b = new StringBuilder();
b.append(theMethod.getName());
b.append(" returns(");
b.append(theMethod.getReturnType().getName());
b.append(") params(");
Class[] parameterTypes = theMethod.getParameterTypes();
for (int i = 0, parameterTypesLength = parameterTypes.length; i < parameterTypesLength; i++) {
if (i > 0) {
b.append(", ");
}
Class next = parameterTypes[i];
b.append(next.getName());
}
b.append(")");
return b.toString();
}
public static Class getGenericCollectionTypeOfField(Field next) {
ParameterizedType collectionType = (ParameterizedType) next.getGenericType();
return getGenericCollectionTypeOf(collectionType.getActualTypeArguments()[0]);
}
/**
* For a field of type List>, returns Foo
*/
public static Class getGenericCollectionTypeOfFieldWithSecondOrderForList(Field next) {
if (!List.class.isAssignableFrom(next.getType())) {
return getGenericCollectionTypeOfField(next);
}
Class type;
ParameterizedType collectionType = (ParameterizedType) next.getGenericType();
Type firstArg = collectionType.getActualTypeArguments()[0];
if (ParameterizedType.class.isAssignableFrom(firstArg.getClass())) {
ParameterizedType pt = ((ParameterizedType) firstArg);
Type pt2 = pt.getActualTypeArguments()[0];
return (Class) pt2;
}
type = (Class) firstArg;
return type;
}
public static Class getGenericCollectionTypeOfMethodParameter(Method theMethod, int theParamIndex) {
Type genericParameterType = theMethod.getGenericParameterTypes()[theParamIndex];
if (Class.class.equals(genericParameterType) || Class.class.equals(genericParameterType.getClass())) {
return null;
}
ParameterizedType collectionType = (ParameterizedType) genericParameterType;
return getGenericCollectionTypeOf(collectionType.getActualTypeArguments()[0]);
}
public static Class getGenericCollectionTypeOfMethodReturnType(Method theMethod) {
Type genericReturnType = theMethod.getGenericReturnType();
if (!(genericReturnType instanceof ParameterizedType)) {
return null;
}
ParameterizedType collectionType = (ParameterizedType) genericReturnType;
return getGenericCollectionTypeOf(collectionType.getActualTypeArguments()[0]);
}
@SuppressWarnings({"rawtypes"})
private static Class getGenericCollectionTypeOf(Type theType) {
Class type;
if (ParameterizedType.class.isAssignableFrom(theType.getClass())) {
ParameterizedType pt = ((ParameterizedType) theType);
type = (Class) pt.getRawType();
} else if (theType instanceof TypeVariable) {
Type decl = ((TypeVariable) theType).getBounds()[0];
return (Class) decl;
} else if (theType instanceof WildcardType) {
Type decl = ((WildcardType) theType).getUpperBounds()[0];
return (Class) decl;
} else {
type = (Class) theType;
}
return type;
}
public static boolean isInstantiable(Class theType) {
return !theType.isInterface() && !Modifier.isAbstract(theType.getModifiers());
}
/**
* Instantiate a class by no-arg constructor, throw {@link ConfigurationException} if we fail to do so
*/
public static T newInstance(Class theType) {
Validate.notNull(theType, "theType must not be null");
try {
return theType.getConstructor().newInstance();
} catch (Exception e) {
throw new ConfigurationException(Msg.code(1784) + "Failed to instantiate " + theType.getName(), e);
}
}
public static T newInstance(Class theType, Class theArgumentType, Object theArgument) {
Validate.notNull(theType, "theType must not be null");
try {
Constructor constructor = theType.getConstructor(theArgumentType);
return constructor.newInstance(theArgument);
} catch (Exception e) {
throw new ConfigurationException(Msg.code(1785) + "Failed to instantiate " + theType.getName(), e);
}
}
public static Object newInstanceOfFhirServerType(String theType) {
String errorMessage =
"Unable to instantiate server framework. Please make sure that hapi-fhir-server library is on your classpath!";
String wantedType = "ca.uhn.fhir.rest.api.server.IFhirVersionServer";
return newInstanceOfType(theType, theType, errorMessage, wantedType, new Class[0], new Object[0]);
}
private static Object newInstanceOfType(
String theKey,
String theType,
String errorMessage,
String wantedType,
Class[] theParameterArgTypes,
Object[] theConstructorArgs) {
Object fhirServerVersion = ourFhirServerVersions.get(theKey);
if (fhirServerVersion == null) {
try {
Class type = Class.forName(theType);
Class serverType = Class.forName(wantedType);
Validate.isTrue(serverType.isAssignableFrom(type));
fhirServerVersion = type.getConstructor(theParameterArgTypes).newInstance(theConstructorArgs);
} catch (Exception e) {
throw new ConfigurationException(Msg.code(1786) + errorMessage, e);
}
ourFhirServerVersions.put(theKey, fhirServerVersion);
}
return fhirServerVersion;
}
public static T newInstanceOrReturnNull(String theClassName, Class theType) {
return newInstanceOrReturnNull(theClassName, theType, EMPTY_CLASS_ARRAY, EMPTY_OBJECT_ARRAY);
}
@SuppressWarnings("unchecked")
public static T newInstanceOrReturnNull(
String theClassName, Class theType, Class[] theArgTypes, Object[] theArgs) {
try {
return newInstance(theClassName, theType, theArgTypes, theArgs);
} catch (ConfigurationException e) {
throw e;
} catch (Exception e) {
ourLog.info("Failed to instantiate {}: {}", theClassName, e.toString());
return null;
}
}
@Nonnull
public static T newInstance(String theClassName, Class theType, Class[] theArgTypes, Object[] theArgs) {
try {
Class clazz = Class.forName(theClassName);
if (!theType.isAssignableFrom(clazz)) {
throw new ConfigurationException(Msg.code(1787) + theClassName + " is not assignable to " + theType);
}
return (T) clazz.getConstructor(theArgTypes).newInstance(theArgs);
} catch (ClassNotFoundException
| NoSuchMethodException
| InstantiationException
| IllegalAccessException
| InvocationTargetException e) {
throw new InternalErrorException(Msg.code(2330) + e.getMessage(), e);
}
}
public static boolean typeExists(String theName) {
try {
Class.forName(theName);
return true;
} catch (ClassNotFoundException theE) {
return false;
}
}
}