org.bardframework.commons.utils.ReflectionUtils Maven / Gradle / Ivy
package org.bardframework.commons.utils;
import lombok.experimental.UtilityClass;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.reflections.Reflections;
import org.reflections.scanners.Scanners;
import java.lang.annotation.Annotation;
import java.lang.reflect.*;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Created by Vahid Zafari on 8/12/2016.
*/
@UtilityClass
@Slf4j
public class ReflectionUtils {
/**
* Pre-built MethodFilter that matches all non-bridge non-synthetic methods
* which are not declared on {@code java.lang.Object}.
*/
public static final MethodFilter USER_DECLARED_METHODS = (method -> !method.isBridge() && !method.isSynthetic());
/**
* Pre-built FieldFilter that matches all non-static, non-final fields.
*/
public static final FieldFilter COPYABLE_FIELDS = (field -> !(Modifier.isStatic(field.getModifiers()) || Modifier.isFinal(field.getModifiers())));
private static final String UNACCEPTABLE_NULL_CLAZZ = "null clazz not acceptable";
private static final String UNACCEPTABLE_FIELD_PATH = "null or empty field path not acceptable";
/**
* Naming prefix for CGLIB-renamed methods.
*/
private static final String CGLIB_RENAMED_METHOD_PREFIX = "CGLIB$";
private static final Class[] EMPTY_CLASS_ARRAY = new Class[0];
private static final Method[] EMPTY_METHOD_ARRAY = new Method[0];
private static final Field[] EMPTY_FIELD_ARRAY = new Field[0];
private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
public static T newInstance(Class clazz) {
try {
return clazz.getConstructor().newInstance();
} catch (IllegalAccessException | InstantiationException | NoSuchMethodException |
InvocationTargetException e) {
log.error("can't instantiate class using empty constructor {}", clazz, e);
throw new IllegalArgumentException("can't instantiate class using empty constructor" + clazz, e);
}
}
public static Class getGenericArgType(Class clazz, int genericArgIndex) {
Class targetClazz = clazz;
/*
find first generic parent
*/
ParameterizedType parameterizedType = null;
while (null == parameterizedType && null != targetClazz.getGenericSuperclass()) {
if (targetClazz.getGenericSuperclass() instanceof ParameterizedType) {
if (((ParameterizedType) targetClazz.getGenericSuperclass()).getActualTypeArguments().length >= genericArgIndex + 1) {
parameterizedType = (ParameterizedType) targetClazz.getGenericSuperclass();
continue;
}
}
targetClazz = targetClazz.getSuperclass();
}
if (null == parameterizedType) {
throw new IllegalArgumentException("can't determine generic arg class at index: " + genericArgIndex + " for class: " + clazz);
}
try {
Type type = ((ParameterizedType) targetClazz.getGenericSuperclass()).getActualTypeArguments()[genericArgIndex];
if (type instanceof Class) {
return (Class) type;
}
throw new IllegalArgumentException("can't determine class from generic type!");
} catch (Exception e) {
log.debug("can't determine class from generic type, at index [{}]", genericArgIndex, e);
throw new IllegalArgumentException("can't determine class from generic type!", e);
}
}
/**
* Finds the first field on the given class matching the given {@link FieldFilter}.
*
* @param type must not be {@literal null}.
* @param filter must not be {@literal null}.
* @return the field matching the filter or {@literal null} in case no field could be found.
*/
public static Field findField(Class type, FieldFilter filter) {
return findField(type, new DescribedFieldFilter() {
@Override
public boolean matches(Field field) {
return filter.matches(field);
}
@Override
public String getDescription() {
return String.format("FieldFilter %s", filter.toString());
}
}, false);
}
/**
* Finds the field matching the given {@link DescribedFieldFilter}. Will make sure there's only one field matching the
* filter.
*
* @param type must not be {@literal null}.
* @param filter must not be {@literal null}.
* @return the field matching the given {@link DescribedFieldFilter} or {@literal null} if none found.
* @throws IllegalStateException in case more than one matching field is found
*/
public static Field findField(Class type, DescribedFieldFilter filter) {
return findField(type, filter, true);
}
/**
* Finds the field matching the given {@link DescribedFieldFilter}. Will make sure there's only one field matching the
* filter in case {@code enforceUniqueness} is {@literal true}.
*
* @param type must not be {@literal null}.
* @param filter must not be {@literal null}.
* @param enforceUniqueness whether to enforce uniqueness of the field
* @return the field matching the given {@link DescribedFieldFilter} or {@literal null} if none found.
* @throws IllegalStateException if enforceUniqueness is true and more than one matching field is found
*/
public static Field findField(Class type, DescribedFieldFilter filter, boolean enforceUniqueness) {
AssertionUtils.notNull(type, "Type must not be null!");
AssertionUtils.notNull(filter, "Filter must not be null!");
Class targetClass = type;
Field foundField = null;
while (targetClass != Object.class) {
for (Field field : targetClass.getDeclaredFields()) {
if (!filter.matches(field)) {
continue;
}
if (!enforceUniqueness) {
return field;
}
if (foundField != null) {
throw new IllegalStateException(filter.getDescription());
}
foundField = field;
}
targetClass = targetClass.getSuperclass();
}
return foundField;
}
/**
* Finds the field of the given name on the given type.
*
* @param type must not be {@literal null}.
* @param name must not be {@literal null} or empty.
* @throws IllegalArgumentException in case the field can't be found.
*/
public static Field findRequiredField(Class type, String name) {
Field result = ReflectionUtils.findField(type, name);
if (result == null) {
throw new IllegalArgumentException(String.format("Unable to find field %s on %s!", name, type));
}
return result;
}
/**
* Returns the method with the given name of the given class and parameter types.
*
* @param type must not be {@literal null}.
* @param name must not be {@literal null}.
* @param parameterTypes must not be {@literal null}.
* @throws IllegalArgumentException in case the method cannot be resolved.
*/
public static Method findRequiredMethod(Class type, String name, Class... parameterTypes) {
Method result = ReflectionUtils.findMethod(type, name, parameterTypes);
if (result == null) {
String parameterTypeNames = Arrays.stream(parameterTypes) //
.map(Object::toString) //
.collect(Collectors.joining(", "));
throw new IllegalArgumentException(
String.format("Unable to find method %s(%s)on %s!", name, parameterTypeNames, type));
}
return result;
}
/**
* Returns a {@link Stream} of the return and parameters types of the given {@link Method}.
*
* @param method must not be {@literal null}.
*/
public static Stream> returnTypeAndParameters(Method method) {
AssertionUtils.notNull(method, "Method must not be null!");
Stream> returnType = Stream.of(method.getReturnType());
Stream> parameterTypes = Arrays.stream(method.getParameterTypes());
return Stream.concat(returnType, parameterTypes);
}
/**
* Get default value for a primitive type.
*
* @param type must not be {@literal null}.
* @return boxed primitive default value.
*/
public static Object getPrimitiveDefault(Class type) {
if (type == Byte.TYPE || type == Byte.class) {
return (byte) 0;
}
if (type == Short.TYPE || type == Short.class) {
return (short) 0;
}
if (type == Integer.TYPE || type == Integer.class) {
return 0;
}
if (type == Long.TYPE || type == Long.class) {
return 0L;
}
if (type == Float.TYPE || type == Float.class) {
return 0F;
}
if (type == Double.TYPE || type == Double.class) {
return 0D;
}
if (type == Character.TYPE || type == Character.class) {
return '\u0000';
}
if (type == Boolean.TYPE) {
return Boolean.FALSE;
}
throw new IllegalArgumentException(String.format("Primitive type %s not supported!", type));
}
public static Field getDeclaredField(Class clazz, String name)
throws NoSuchFieldException {
try {
return clazz.getDeclaredField(name);
} catch (NoSuchFieldException e) {
if (Object.class != clazz.getSuperclass()) {
return getDeclaredField(clazz.getSuperclass(), name);
} else {
throw e;
}
}
}
/**
* @return value of property path of root object
*/
public static Object getPropertyValue(final Object root, String propertyPath)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
if (root == null) {
throw new IllegalArgumentException("null object not acceptable");
}
if (propertyPath == null || propertyPath.isEmpty()) {
throw new IllegalArgumentException("null or empty what not acceptable");
}
Object current = root;
String[] properties = propertyPath.split("\\.");
for (String property : properties) {
if (current == null) {
return null;
}
current = getGetter(current.getClass(), property).invoke(current);
}
return current;
}
public static Field getField(Class clazz, String fieldPath) {
if (clazz == null) {
throw new IllegalArgumentException(UNACCEPTABLE_NULL_CLAZZ);
}
if (StringUtils.isBlank(fieldPath)) {
throw new IllegalArgumentException(UNACCEPTABLE_FIELD_PATH);
}
Class currentClazz = clazz;
String[] fieldPaths = fieldPath.split("\\.");
Field field = null;
for (String fieldName : fieldPaths) {
field = ReflectionUtils.findField(currentClazz, fieldName);
if (null == field) {
return null;
}
currentClazz = field.getType();
}
return field;
}
public static Class getContainerCLassByField(Class clazz, String fieldPath) {
if (clazz == null) {
throw new IllegalArgumentException(UNACCEPTABLE_NULL_CLAZZ);
}
if (StringUtils.isBlank(fieldPath)) {
throw new IllegalArgumentException(UNACCEPTABLE_FIELD_PATH);
}
Class currentClazz = clazz;
String[] fieldPaths = fieldPath.split("\\.");
for (int i = 0; i < fieldPaths.length - 1; i++) {
currentClazz = findField(currentClazz, fieldPaths[i]).getType();
}
return currentClazz;
}
public static Method getGetterMethod(Class clazz, String fieldPath)
throws NoSuchMethodException {
if (clazz == null) {
throw new IllegalArgumentException(UNACCEPTABLE_NULL_CLAZZ);
}
if (StringUtils.isBlank(fieldPath)) {
throw new IllegalArgumentException(UNACCEPTABLE_FIELD_PATH);
}
Class currentClazz = clazz;
String[] fieldPaths = fieldPath.split("\\.");
Method method = null;
for (String fieldName : fieldPaths) {
method = getGetter(currentClazz, fieldName);
currentClazz = method.getReturnType();
}
return method;
}
public static Class getContainerClassByGetter(Class clazz, String fieldPath)
throws NoSuchMethodException {
if (clazz == null) {
throw new IllegalArgumentException(UNACCEPTABLE_NULL_CLAZZ);
}
if (StringUtils.isBlank(fieldPath)) {
throw new IllegalArgumentException(UNACCEPTABLE_FIELD_PATH);
}
Class currentClazz = clazz;
String[] fieldPaths = fieldPath.split("\\.");
for (int i = 0; i < fieldPaths.length - 1; i++) {
currentClazz = getGetter(currentClazz, fieldPaths[i]).getReturnType();
}
return currentClazz;
}
public static Object setValue(final Object root, final String path, final Object value)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException, InstantiationException {
if (root == null) {
throw new IllegalArgumentException("null root not acceptable");
}
if (path == null || path.isEmpty()) {
throw new IllegalArgumentException("null or empty what not acceptable");
}
if (null == value) {
return root;
}
Object current = root;
String[] callList = path.split("\\.");
for (int i = 0; i < callList.length - 1; i++) {
Method getter = getGetter(current.getClass(), callList[i]);
Object result = getter.invoke(current);
if (result == null) {
result = getter.getReturnType().getConstructor().newInstance();
getSetter(current.getClass(), callList[i], result.getClass()).invoke(current, result);
}
current = result;
}
try {
getSetter(current.getClass(), callList[callList.length - 1], value.getClass()).invoke(current, value);
} catch (NoSuchMethodException e) {
Class clazz;
if (value.getClass().equals(Byte.class)) {
clazz = byte.class;
} else if (value.getClass().equals(Short.class)) {
clazz = short.class;
} else if (value.getClass().equals(Integer.class)) {
clazz = int.class;
} else if (value.getClass().equals(Long.class)) {
clazz = long.class;
} else {
throw e;
}
getSetter(current.getClass(), callList[callList.length - 1], clazz).invoke(current, value);
}
return current;
}
public static Method getSetter(Class aClass, final String property, Class... parameterType)
throws NoSuchMethodException {
if (aClass == null) {
throw new IllegalArgumentException("null _class not accepted");
}
if (property == null || property.isEmpty()) {
throw new IllegalArgumentException("null or empty property not accepted");
}
return aClass.getMethod(getSetterName(property.trim()), parameterType);
}
public static Method getGetter(Class aClass, final String property)
throws NoSuchMethodException {
if (aClass == null) {
throw new IllegalArgumentException("null _class not accepted");
}
if (property == null || property.isEmpty()) {
throw new IllegalArgumentException("null or empty property not accepted");
}
try {
return aClass.getMethod(getGetterName(property.trim(), String.class));
} catch (NoSuchMethodException | SecurityException ex) {
return aClass.getMethod(getGetterName(property.trim(), boolean.class));
}
}
/**
* @throws NoSuchMethodException getCurrentMethod(Thread.currentThread().getStackTrace()[1])
*/
public static Method getCurrentMethod(StackTraceElement stackTraceElement)
throws ClassNotFoundException, NoSuchMethodException {
return Class.forName(stackTraceElement.getClassName()).getMethod(stackTraceElement.getMethodName());
}
/**
* @param property, Class type
* @return getter of the given property, if the given property has boolean
* type add is to its first else add get
*/
public static String getGetterName(String property, Class type) {
property = property.trim();
return (boolean.class.equals(type) || Boolean.class.equals(type) ? "is" : "get") + property.substring(0, 1).toUpperCase() + property.substring(1);
}
public static String getSetterName(String property) {
return "set" + property.substring(0, 1).toUpperCase() + property.substring(1);
}
public static Map getFieldAnnotationMap(Class clazz, Class annotationClazz, boolean includeSuperClasses) {
Map map = new HashMap<>();
for (Field field : clazz.getDeclaredFields()) {
if (!field.isAnnotationPresent(annotationClazz)) {
continue;
}
map.put(field, field.getAnnotation(annotationClazz));
}
if (includeSuperClasses && !Object.class.equals(clazz.getSuperclass())) {
map.putAll(getFieldAnnotationMap(clazz.getSuperclass(), annotationClazz, true));
}
return map;
}
public static List getFields(Class clazz, Class annotationClazz, boolean includeSuperClasses) {
List fields = new ArrayList<>();
for (Field field : clazz.getDeclaredFields()) {
if (!field.isAnnotationPresent(annotationClazz)) {
continue;
}
fields.add(field);
}
if (includeSuperClasses && !Object.class.equals(clazz.getSuperclass())) {
fields.addAll(getFields(clazz.getSuperclass(), annotationClazz, true));
}
return fields;
}
public static Set fetchPropertyFields(Set allFields, String fieldName) {
AssertionUtils.notNull(fieldName, "null field name not acceptable");
Set fields = new HashSet<>();
if (null == allFields) {
return fields;
}
allFields.forEach(field -> {
if (field.startsWith(fieldName + ".")) {
fields.add(field.replaceFirst(fieldName + ".", StringUtils.EMPTY));
}
});
if (!fields.isEmpty()) {
fields.add(fieldName);
}
return fields;
}
public static boolean isContainField(Set fields, String fieldName) {
AssertionUtils.notNull(fieldName, "null field name not acceptable");
if (null == fields) {
return false;
}
for (String field : fields) {
if (field.equals(fieldName) || field.startsWith(fieldName + ".")) {
return true;
}
}
return false;
}
public static String methodToFieldName(Method method) {
String name = method.getName();
if (name.startsWith("get")) {
name = name.replaceFirst("get", StringUtils.EMPTY);
} else if (name.startsWith("is")) {
name = name.replaceFirst("is", StringUtils.EMPTY);
}
return lowerCaseFirstLetter(name);
}
public static String lowerCaseFirstLetter(String name) {
StringBuilder builder = new StringBuilder(name);
builder.setCharAt(0, Character.toLowerCase(builder.charAt(0)));
return builder.toString();
}
/**
* Handle the given reflection exception.
* Should only be called if no checked exception is expected to be thrown
* by a target method, or if an error occurs while accessing a method or field.
*
Throws the underlying RuntimeException or Error in case of an
* InvocationTargetException with such a root cause. Throws an
* IllegalStateException with an appropriate message or
* UndeclaredThrowableException otherwise.
*
* @param ex the reflection exception to handle
*/
public static void handleReflectionException(Exception ex) {
if (ex instanceof NoSuchMethodException) {
throw new IllegalStateException("Method not found: " + ex.getMessage());
}
if (ex instanceof IllegalAccessException) {
throw new IllegalStateException("Could not access method or field: " + ex.getMessage());
}
if (ex instanceof InvocationTargetException) {
handleInvocationTargetException((InvocationTargetException) ex);
}
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
throw new UndeclaredThrowableException(ex);
}
/**
* Handle the given invocation target exception. Should only be called if no
* checked exception is expected to be thrown by the target method.
*
Throws the underlying RuntimeException or Error in case of such a root
* cause. Throws an UndeclaredThrowableException otherwise.
*
* @param ex the invocation target exception to handle
*/
public static void handleInvocationTargetException(InvocationTargetException ex) {
rethrowRuntimeException(ex.getTargetException());
}
/**
* Rethrow the given {@link Throwable exception}, which is presumably the
* target exception of an {@link InvocationTargetException}.
* Should only be called if no checked exception is expected to be thrown
* by the target method.
*
Rethrows the underlying exception cast to a {@link RuntimeException} or
* {@link Error} if appropriate; otherwise, throws an
* {@link UndeclaredThrowableException}.
*
* @param ex the exception to rethrow
* @throws RuntimeException the rethrown exception
*/
public static void rethrowRuntimeException(Throwable ex) {
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
if (ex instanceof Error) {
throw (Error) ex;
}
throw new UndeclaredThrowableException(ex);
}
/**
* Rethrow the given {@link Throwable exception}, which is presumably the
* target exception of an {@link InvocationTargetException}.
* Should only be called if no checked exception is expected to be thrown
* by the target method.
*
Rethrows the underlying exception cast to an {@link Exception} or
* {@link Error} if appropriate; otherwise, throws an
* {@link UndeclaredThrowableException}.
*
* @param ex the exception to rethrow
* @throws Exception the rethrown exception (in case of a checked exception)
*/
public static void rethrowException(Throwable ex) throws Exception {
if (ex instanceof Exception) {
throw (Exception) ex;
}
if (ex instanceof Error) {
throw (Error) ex;
}
throw new UndeclaredThrowableException(ex);
}
/**
* Obtain an accessible constructor for the given class and parameters.
*
* @param clazz the clazz to check
* @param parameterTypes the parameter types of the desired constructor
* @return the constructor reference
* @throws NoSuchMethodException if no such constructor exists
*/
public static Constructor accessibleConstructor(Class clazz, Class... parameterTypes)
throws NoSuchMethodException {
Constructor ctor = clazz.getDeclaredConstructor(parameterTypes);
makeAccessible(ctor);
return ctor;
}
// Constructor handling
/**
* Make the given constructor accessible, explicitly setting it accessible
* if necessary. The {@code setAccessible(true)} method is only called
* when actually necessary, to avoid unnecessary conflicts with a JVM
* SecurityManager (if active).
*
* @param ctor the constructor to make accessible
*/
@SuppressWarnings("deprecation") // on JDK 9
public static void makeAccessible(Constructor ctor) {
if ((!Modifier.isPublic(ctor.getModifiers()) ||
!Modifier.isPublic(ctor.getDeclaringClass().getModifiers())) && !ctor.isAccessible()) {
ctor.setAccessible(true);
}
}
/**
* Attempt to find a {@link Method} on the supplied class with the supplied name
* and no parameters. Searches all superclasses up to {@code Object}.
* Returns {@code null} if no {@link Method} can be found.
*
* @param clazz the class to introspect
* @param name the name of the method
* @return the Method object, or {@code null} if none found
*/
public static Method findMethod(Class clazz, String name) {
return findMethod(clazz, name, EMPTY_CLASS_ARRAY);
}
// Method handling
/**
* Attempt to find a {@link Method} on the supplied class with the supplied name
* and parameter types. Searches all superclasses up to {@code Object}.
*
Returns {@code null} if no {@link Method} can be found.
*
* @param clazz the class to introspect
* @param name the name of the method
* @param paramTypes the parameter types of the method
* (may be {@code null} to indicate any signature)
* @return the Method object, or {@code null} if none found
*/
public static Method findMethod(Class clazz, String name, Class... paramTypes) {
AssertionUtils.notNull(clazz, "Class must not be null");
AssertionUtils.notNull(name, "Method name must not be null");
Class searchType = clazz;
while (searchType != null) {
Method[] methods = (searchType.isInterface() ? searchType.getMethods() :
getDeclaredMethods(searchType, false));
for (Method method : methods) {
if (name.equals(method.getName()) && (paramTypes == null || hasSameParams(method, paramTypes))) {
return method;
}
}
searchType = searchType.getSuperclass();
}
return null;
}
private static boolean hasSameParams(Method method, Class[] paramTypes) {
return (paramTypes.length == method.getParameterCount() &&
Arrays.equals(paramTypes, method.getParameterTypes()));
}
/**
* Invoke the specified {@link Method} against the supplied target object with no arguments.
* The target object can be {@code null} when invoking a static {@link Method}.
*
Thrown exceptions are handled via a call to {@link #handleReflectionException}.
*
* @param method the method to invoke
* @param target the target object to invoke the method on
* @return the invocation result, if any
*/
public static Object invokeMethod(Method method, Object target) {
return invokeMethod(method, target, EMPTY_OBJECT_ARRAY);
}
/**
* Invoke the specified {@link Method} against the supplied target object with the
* supplied arguments. The target object can be {@code null} when invoking a
* static {@link Method}.
*
Thrown exceptions are handled via a call to {@link #handleReflectionException}.
*
* @param method the method to invoke
* @param target the target object to invoke the method on
* @param args the invocation arguments (may be {@code null})
* @return the invocation result, if any
*/
public static Object invokeMethod(Method method, Object target, Object... args) {
try {
return method.invoke(target, args);
} catch (Exception ex) {
handleReflectionException(ex);
}
throw new IllegalStateException("Should never get here");
}
/**
* Determine whether the given method explicitly declares the given
* exception or one of its superclasses, which means that an exception
* of that type can be propagated as-is within a reflective invocation.
*
* @param method the declaring method
* @param exceptionType the exception to throw
* @return {@code true} if the exception can be thrown as-is;
* {@code false} if it needs to be wrapped
*/
public static boolean declaresException(Method method, Class exceptionType) {
AssertionUtils.notNull(method, "Method must not be null");
Class[] declaredExceptions = method.getExceptionTypes();
for (Class declaredException : declaredExceptions) {
if (declaredException.isAssignableFrom(exceptionType)) {
return true;
}
}
return false;
}
/**
* Perform the given callback operation on all matching methods of the given
* class, as locally declared or equivalent thereof (such as default methods
* on Java 8 based interfaces that the given class implements).
*
* @param clazz the class to introspect
* @param mc the callback to invoke for each method
* @throws IllegalStateException if introspection fails
*/
public static void doWithLocalMethods(Class clazz, MethodCallback mc) {
Method[] methods = getDeclaredMethods(clazz, false);
for (Method method : methods) {
mc.doWith(method);
}
}
/**
* Perform the given callback operation on all matching methods of the given
* class and superclasses.
*
The same named method occurring on subclass and superclass will appear
* twice, unless excluded by a {@link MethodFilter}.
*
* @param clazz the class to introspect
* @param mc the callback to invoke for each method
* @throws IllegalStateException if introspection fails
*/
public static void doWithMethods(Class clazz, MethodCallback mc) {
doWithMethods(clazz, mc, null);
}
/**
* Perform the given callback operation on all matching methods of the given
* class and superclasses (or given interface and super-interfaces).
*
The same named method occurring on subclass and superclass will appear
* twice, unless excluded by the specified {@link MethodFilter}.
*
* @param clazz the class to introspect
* @param mc the callback to invoke for each method
* @param mf the filter that determines the methods to apply the callback to
* @throws IllegalStateException if introspection fails
*/
public static void doWithMethods(Class clazz, MethodCallback mc, MethodFilter mf) {
// Keep backing up the inheritance hierarchy.
Method[] methods = getDeclaredMethods(clazz, false);
for (Method method : methods) {
if (mf != null && !mf.matches(method)) {
continue;
}
mc.doWith(method);
}
if (clazz.getSuperclass() != null && (mf != USER_DECLARED_METHODS || clazz.getSuperclass() != Object.class)) {
doWithMethods(clazz.getSuperclass(), mc, mf);
} else if (clazz.isInterface()) {
for (Class superIfc : clazz.getInterfaces()) {
doWithMethods(superIfc, mc, mf);
}
}
}
/**
* Get all declared methods on the leaf class and all superclasses.
* Leaf class methods are included first.
*
* @param leafClass the class to introspect
* @throws IllegalStateException if introspection fails
*/
public static Method[] getAllDeclaredMethods(Class leafClass) {
final List methods = new ArrayList<>(32);
doWithMethods(leafClass, methods::add);
return methods.toArray(EMPTY_METHOD_ARRAY);
}
/**
* Get the unique set of declared methods on the leaf class and all superclasses.
* Leaf class methods are included first and while traversing the superclass hierarchy
* any methods found with signatures matching a method already included are filtered out.
*
* @param leafClass the class to introspect
* @throws IllegalStateException if introspection fails
*/
public static Method[] getUniqueDeclaredMethods(Class leafClass) {
return getUniqueDeclaredMethods(leafClass, null);
}
/**
* Get the unique set of declared methods on the leaf class and all superclasses.
* Leaf class methods are included first and while traversing the superclass hierarchy
* any methods found with signatures matching a method already included are filtered out.
*
* @param leafClass the class to introspect
* @param mf the filter that determines the methods to take into account
* @throws IllegalStateException if introspection fails
*/
public static Method[] getUniqueDeclaredMethods(Class leafClass, MethodFilter mf) {
final List methods = new ArrayList<>(32);
doWithMethods(leafClass, method -> {
boolean knownSignature = false;
Method methodBeingOverriddenWithCovariantReturnType = null;
for (Method existingMethod : methods) {
if (method.getName().equals(existingMethod.getName()) &&
method.getParameterCount() == existingMethod.getParameterCount() &&
Arrays.equals(method.getParameterTypes(), existingMethod.getParameterTypes())) {
// Is this a covariant return type situation?
if (existingMethod.getReturnType() != method.getReturnType() &&
existingMethod.getReturnType().isAssignableFrom(method.getReturnType())) {
methodBeingOverriddenWithCovariantReturnType = existingMethod;
} else {
knownSignature = true;
}
break;
}
}
if (methodBeingOverriddenWithCovariantReturnType != null) {
methods.remove(methodBeingOverriddenWithCovariantReturnType);
}
if (!knownSignature && !isCglibRenamedMethod(method)) {
methods.add(method);
}
}, mf);
return methods.toArray(EMPTY_METHOD_ARRAY);
}
/**
* Variant of {@link Class#getDeclaredMethods()} that uses a local cache in
* order to avoid the JVM's SecurityManager check and new Method instances.
* In addition, it also includes Java 8 default methods from locally
* implemented interfaces, since those are effectively to be treated just
* like declared methods.
*
* @param clazz the class to introspect
* @return the cached array of methods
* @throws IllegalStateException if introspection fails
*/
public static Method[] getDeclaredMethods(Class clazz) {
return getDeclaredMethods(clazz, true);
}
private static Method[] getDeclaredMethods(Class clazz, boolean defensive) {
AssertionUtils.notNull(clazz, "Class must not be null");
Method[] result;
try {
Method[] declaredMethods = clazz.getDeclaredMethods();
List defaultMethods = findConcreteMethodsOnInterfaces(clazz);
if (defaultMethods != null) {
result = new Method[declaredMethods.length + defaultMethods.size()];
System.arraycopy(declaredMethods, 0, result, 0, declaredMethods.length);
int index = declaredMethods.length;
for (Method defaultMethod : defaultMethods) {
result[index] = defaultMethod;
index++;
}
} else {
result = declaredMethods;
}
} catch (Throwable ex) {
throw new IllegalStateException("Failed to introspect Class [" + clazz.getName() +
"] from ClassLoader [" + clazz.getClassLoader() + "]", ex);
}
return (result.length == 0 || !defensive) ? result : result.clone();
}
private static List findConcreteMethodsOnInterfaces(Class clazz) {
List result = null;
for (Class ifc : clazz.getInterfaces()) {
for (Method ifcMethod : ifc.getMethods()) {
if (!Modifier.isAbstract(ifcMethod.getModifiers())) {
if (result == null) {
result = new ArrayList<>();
}
result.add(ifcMethod);
}
}
}
return result;
}
/**
* Determine whether the given method is an "equals" method.
*/
public static boolean isEqualsMethod(Method method) {
if (method == null || !method.getName().equals("equals")) {
return false;
}
if (method.getParameterCount() != 1) {
return false;
}
return method.getParameterTypes()[0] == Object.class;
}
/**
* Determine whether the given method is a "hashCode" method.
*/
public static boolean isHashCodeMethod(Method method) {
return (method != null && method.getName().equals("hashCode") && method.getParameterCount() == 0);
}
/**
* Determine whether the given method is a "toString" method.
*/
public static boolean isToStringMethod(Method method) {
return (method != null && method.getName().equals("toString") && method.getParameterCount() == 0);
}
/**
* Determine whether the given method is originally declared by {@link Object}.
*/
public static boolean isObjectMethod(Method method) {
return (method != null && (method.getDeclaringClass() == Object.class ||
isEqualsMethod(method) || isHashCodeMethod(method) || isToStringMethod(method)));
}
/**
* Determine whether the given method is a CGLIB 'renamed' method,
* following the pattern "CGLIB$methodName$0".
*
* @param renamedMethod the method to check
*/
public static boolean isCglibRenamedMethod(Method renamedMethod) {
String name = renamedMethod.getName();
if (name.startsWith(CGLIB_RENAMED_METHOD_PREFIX)) {
int i = name.length() - 1;
while (i >= 0 && Character.isDigit(name.charAt(i))) {
i--;
}
return (i > CGLIB_RENAMED_METHOD_PREFIX.length() && (i < name.length() - 1) && name.charAt(i) == '$');
}
return false;
}
/**
* Make the given method accessible, explicitly setting it accessible if
* necessary. The {@code setAccessible(true)} method is only called
* when actually necessary, to avoid unnecessary conflicts with a JVM
* SecurityManager (if active).
*
* @param method the method to make accessible
*/
@SuppressWarnings("deprecation") // on JDK 9
public static void makeAccessible(Method method) {
if ((!Modifier.isPublic(method.getModifiers()) ||
!Modifier.isPublic(method.getDeclaringClass().getModifiers())) && !method.isAccessible()) {
method.setAccessible(true);
}
}
/**
* Attempt to find a {@link Field field} on the supplied {@link Class} with the
* supplied {@code name}. Searches all superclasses up to {@link Object}.
*
* @param clazz the class to introspect
* @param name the name of the field
* @return the corresponding Field object, or {@code null} if not found
*/
public static Field findField(Class clazz, String name) {
return findField(clazz, name, null);
}
// Field handling
/**
* Attempt to find a {@link Field field} on the supplied {@link Class} with the
* supplied {@code name} and/or {@link Class type}. Searches all superclasses
* up to {@link Object}.
*
* @param clazz the class to introspect
* @param name the name of the field (may be {@code null} if type is specified)
* @param type the type of the field (may be {@code null} if name is specified)
* @return the corresponding Field object, or {@code null} if not found
*/
public static Field findField(Class clazz, String name, Class type) {
AssertionUtils.notNull(clazz, "Class must not be null");
AssertionUtils.isTrue(name != null || type != null, "Either name or type of the field must be specified");
Class searchType = clazz;
while (Object.class != searchType && searchType != null) {
Field[] fields = getDeclaredFields(searchType);
for (Field field : fields) {
if ((name == null || name.equals(field.getName())) &&
(type == null || type.equals(field.getType()))) {
return field;
}
}
searchType = searchType.getSuperclass();
}
return null;
}
/**
* Set the field represented by the supplied {@linkplain Field field object} on
* the specified {@linkplain Object target object} to the specified {@code value}.
* In accordance with {@link Field#set(Object, Object)} semantics, the new value
* is automatically unwrapped if the underlying field has a primitive type.
*
This method does not support setting {@code static final} fields.
*
Thrown exceptions are handled via a call to {@link #handleReflectionException(Exception)}.
*
* @param field the field to set
* @param target the target object on which to set the field
* @param value the value to set (may be {@code null})
*/
public static void setField(Field field, Object target, Object value) {
try {
field.set(target, value);
} catch (IllegalAccessException ex) {
handleReflectionException(ex);
}
}
/**
* Get the field represented by the supplied {@link Field field object} on the
* specified {@link Object target object}. In accordance with {@link Field#get(Object)}
* semantics, the returned value is automatically wrapped if the underlying field
* has a primitive type.
*
Thrown exceptions are handled via a call to {@link #handleReflectionException(Exception)}.
*
* @param field the field to get
* @param target the target object from which to get the field
* @return the field's current value
*/
public static Object getField(Field field, Object target) {
try {
return field.get(target);
} catch (IllegalAccessException ex) {
handleReflectionException(ex);
}
throw new IllegalStateException("Should never get here");
}
/**
* Invoke the given callback on all locally declared fields in the given class.
*
* @param clazz the target class to analyze
* @param fc the callback to invoke for each field
* @throws IllegalStateException if introspection fails
*/
public static void doWithLocalFields(Class clazz, FieldCallback fc) {
for (Field field : getDeclaredFields(clazz)) {
try {
fc.doWith(field);
} catch (IllegalAccessException ex) {
throw new IllegalStateException("Not allowed to access field '" + field.getName() + "': " + ex);
}
}
}
/**
* Invoke the given callback on all fields in the target class, going up the
* class hierarchy to get all declared fields.
*
* @param clazz the target class to analyze
* @param fc the callback to invoke for each field
* @throws IllegalStateException if introspection fails
*/
public static void doWithFields(Class clazz, FieldCallback fc) {
doWithFields(clazz, fc, null);
}
/**
* Invoke the given callback on all fields in the target class, going up the
* class hierarchy to get all declared fields.
*
* @param clazz the target class to analyze
* @param fc the callback to invoke for each field
* @param ff the filter that determines the fields to apply the callback to
* @throws IllegalStateException if introspection fails
*/
public static void doWithFields(Class clazz, FieldCallback fc, FieldFilter ff) {
// Keep backing up the inheritance hierarchy.
Class targetClass = clazz;
do {
Field[] fields = getDeclaredFields(targetClass);
for (Field field : fields) {
if (ff != null && !ff.matches(field)) {
continue;
}
try {
fc.doWith(field);
} catch (IllegalAccessException ex) {
throw new IllegalStateException("Not allowed to access field '" + field.getName() + "': " + ex);
}
}
targetClass = targetClass.getSuperclass();
}
while (targetClass != null && targetClass != Object.class);
}
/**
* This variant retrieves {@link Class#getDeclaredFields()} from a local cache
* in order to avoid the JVM's SecurityManager check and defensive array copying.
*
* @param clazz the class to introspect
* @return the cached array of fields
* @throws IllegalStateException if introspection fails
*/
private static Field[] getDeclaredFields(Class clazz) {
AssertionUtils.notNull(clazz, "Class must not be null");
Field[] result;
try {
result = clazz.getDeclaredFields();
} catch (Throwable ex) {
throw new IllegalStateException("Failed to introspect Class [" + clazz.getName() + "] from ClassLoader [" + clazz.getClassLoader() + "]", ex);
}
return result;
}
/**
* Given the source object and the destination, which must be the same class
* or a subclass, copy all fields, including inherited fields. Designed to
* work on objects with public no-arg constructors.
*
* @throws IllegalStateException if introspection fails
*/
public static void shallowCopyFieldState(final Object src, final Object dest) {
AssertionUtils.notNull(src, "Source for field copy cannot be null");
AssertionUtils.notNull(dest, "Destination for field copy cannot be null");
if (!src.getClass().isAssignableFrom(dest.getClass())) {
throw new IllegalArgumentException("Destination class [" + dest.getClass().getName() +
"] must be same or subclass as source class [" + src.getClass().getName() + "]");
}
doWithFields(src.getClass(), field -> {
makeAccessible(field);
Object srcValue = field.get(src);
field.set(dest, srcValue);
}, COPYABLE_FIELDS);
}
/**
* Determine whether the given field is a "public static final" constant.
*
* @param field the field to check
*/
public static boolean isPublicStaticFinal(Field field) {
int modifiers = field.getModifiers();
return (Modifier.isPublic(modifiers) && Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers));
}
/**
* Make the given field accessible, explicitly setting it accessible if
* necessary. The {@code setAccessible(true)} method is only called
* when actually necessary, to avoid unnecessary conflicts with a JVM
* SecurityManager (if active).
*
* @param field the field to make accessible
*/
@SuppressWarnings("deprecation") // on JDK 9
public static void makeAccessible(Field field) {
if ((!Modifier.isPublic(field.getModifiers()) ||
!Modifier.isPublic(field.getDeclaringClass().getModifiers()) ||
Modifier.isFinal(field.getModifiers())) && !field.isAccessible()) {
field.setAccessible(true);
}
}
public static Set> getSubTypeOf(String packagePrefix, Class clazz) {
return new Reflections(packagePrefix, Scanners.SubTypes).getSubTypesOf(clazz);
}
public static List> getSupersOf(Class clazz, boolean includeInterface, boolean includeAbstractClasses, boolean includeObjectClass) {
List> supers = new ArrayList<>();
if (null == clazz || clazz.equals(Object.class)) {
return supers;
}
if (includeObjectClass) {
supers.add(Object.class);
}
Class parent = clazz.getSuperclass();
if (null != parent && !Object.class.equals(parent)) {
if (Modifier.isAbstract(parent.getModifiers())) {
if (includeAbstractClasses) {
supers.add(parent);
}
} else {
supers.add(parent);
}
supers.addAll(ReflectionUtils.getSupersOf(parent, includeInterface, includeAbstractClasses, false));
}
if (includeInterface) {
for (Class anInterface : clazz.getInterfaces()) {
supers.add(anInterface);
supers.addAll(ReflectionUtils.getSupersOf(anInterface, true, includeAbstractClasses, false));
}
}
return supers;
}
/**
* A {@link FieldFilter} that has a description.
*
* @author Oliver Gierke
*/
public interface DescribedFieldFilter extends FieldFilter {
/**
* Returns the description of the field filter. Used in exceptions being thrown in case uniqueness shall be enforced
* on the field filter.
*/
String getDescription();
}
/**
* Action to take on each method.
*/
@FunctionalInterface
public interface MethodCallback {
/**
* Perform an operation using the given method.
*
* @param method the method to operate on
*/
void doWith(Method method) throws IllegalArgumentException;
}
/**
* Callback optionally used to filter methods to be operated on by a method callback.
*/
@FunctionalInterface
public interface MethodFilter {
/**
* Determine whether the given method matches.
*
* @param method the method to check
*/
boolean matches(Method method);
}
/**
* Callback interface invoked on each field in the hierarchy.
*/
@FunctionalInterface
public interface FieldCallback {
/**
* Perform an operation using the given field.
*
* @param field the field to operate on
*/
void doWith(Field field) throws IllegalArgumentException, IllegalAccessException;
}
/**
* Callback optionally used to filter fields to be operated on by a field callback.
*/
@FunctionalInterface
public interface FieldFilter {
/**
* Determine whether the given field matches.
*
* @param field the field to check
*/
boolean matches(Field field);
}
}