jodd.util.ReflectUtil Maven / Gradle / Ivy
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
package jodd.util;
import jodd.util.cl.ClassLoaderStrategy;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
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.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Various java.lang.reflect utilities.
*/
public class ReflectUtil {
/** Empty class array. */
public static final Class[] NO_PARAMETERS = new Class[0];
public static final String METHOD_GET_PREFIX = "get";
public static final String METHOD_IS_PREFIX = "is";
public static final String METHOD_SET_PREFIX = "set";
// ---------------------------------------------------------------- method0
private static Method _getMethod0;
static {
try {
_getMethod0 = Class.class.getDeclaredMethod("getMethod0", String.class, Class[].class);
_getMethod0.setAccessible(true);
} catch (Exception ignore) {
try {
_getMethod0 = Class.class.getMethod("getMethod", String.class, Class[].class);
} catch (Exception ignored) {
_getMethod0 = null;
}
}
}
/**
* Invokes private Class.getMethod0() without throwing NoSuchMethodException.
* Returns only public methods or null if method not found. Since no exception is
* throwing, it works faster.
*
* @param c class to inspect
* @param name name of method to find
* @param parameterTypes parameter types
* @return founded method, or null
*/
public static Method getMethod0(Class c, String name, Class... parameterTypes) {
try {
return (Method) _getMethod0.invoke(c, name, parameterTypes);
} catch (Exception ignore) {
return null;
}
}
// ---------------------------------------------------------------- find method
/**
* Returns method from an object, matched by name. This may be considered as
* a slow operation, since methods are matched one by one.
* Returns only accessible methods.
* Only first method is matched.
*
* @param c class to examine
* @param methodName Full name of the method.
* @return null if method not found
*/
public static Method findMethod(Class c, String methodName) {
return findDeclaredMethod(c, methodName, true);
}
/**
* @see #findMethod(Class, String)
*/
public static Method findDeclaredMethod(Class c, String methodName) {
return findDeclaredMethod(c, methodName, false);
}
private static Method findDeclaredMethod(Class c, String methodName, boolean publicOnly) {
if ((methodName == null) || (c == null)) {
return null;
}
Method[] ms = publicOnly ? c.getMethods() : c.getDeclaredMethods();
for (Method m : ms) {
if (m.getName().equals(methodName)) {
return m;
}
}
return null;
}
// ---------------------------------------------------------------- classes
/**
* Returns classes from array of specified objects.
*/
public static Class[] getClasses(Object... objects) {
if (objects == null) {
return null;
}
Class[] result = new Class[objects.length];
for (int i = 0; i < objects.length; i++) {
if (objects[i] != null) {
result[i] = objects[i].getClass();
}
}
return result;
}
// ---------------------------------------------------------------- invoke
/**
* Invokes accessible method of an object.
*
* @param c class that contains method
* @param obj object to execute
* @param method method to invoke
* @param paramClasses classes of parameters
* @param params parameters
*/
public static Object invoke(Class c, Object obj, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = c.getMethod(method, paramClasses);
return m.invoke(obj, params);
}
/**
* Invokes static method.
*/
public static Object invoke(Class c, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = c.getMethod(method, paramClasses);
return m.invoke(null, params);
}
/**
* Invokes accessible method of an object.
*
* @param obj object
* @param method name of the objects method
* @param params method parameters
* @param paramClasses method parameter types
*/
public static Object invoke(Object obj, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = obj.getClass().getMethod(method, paramClasses);
return m.invoke(obj, params);
}
/**
* Invokes accessible method of an object without specifying parameter types.
* @param obj object
* @param method method of an object
* @param params method parameters
*/
public static Object invoke(Object obj, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invoke(obj, method, paramClass, params);
}
public static Object invoke(Class c, Object obj, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invoke(c, obj, method, paramClass, params);
}
/**
* Invokes static method.
*/
public static Object invoke(Class c, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invoke(c, null, method, paramClass, params);
}
// ---------------------------------------------------------------- invokeDeclared
/**
* Invokes any method of a class, even private ones.
*
* @param c class to examine
* @param obj object to inspect
* @param method method to invoke
* @param paramClasses parameter types
* @param params parameters
*/
public static Object invokeDeclared(Class c, Object obj, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = c.getDeclaredMethod(method, paramClasses);
m.setAccessible(true);
return m.invoke(obj, params);
}
public static Object invokeDeclared(Class c, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = c.getDeclaredMethod(method, paramClasses);
m.setAccessible(true);
return m.invoke(null, params);
}
/**
* Invokes any method of a class suppressing java access checking.
*
* @param obj object to inspect
* @param method method to invoke
* @param paramClasses parameter types
* @param params parameters
*/
public static Object invokeDeclared(Object obj, String method, Class[] paramClasses, Object[] params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Method m = obj.getClass().getDeclaredMethod(method, paramClasses);
m.setAccessible(true);
return m.invoke(obj, params);
}
public static Object invokeDeclared(Object obj, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invokeDeclared(obj, method, paramClass, params);
}
public static Object invokeDeclared(Class c, Object obj, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invokeDeclared(c, obj, method, paramClass, params);
}
public static Object invokeDeclared(Class c, String method, Object... params) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
Class[] paramClass = getClasses(params);
return invokeDeclared(c, null, method, paramClass, params);
}
// ---------------------------------------------------------------- match classes
/**
* Safe version of isAssignableFrom method that
* returns false if one of the arguments is null.
*/
public static boolean isTypeOf(Class lookupClass, Class targetClass) {
if (targetClass == null || lookupClass == null) {
return false;
}
return targetClass.isAssignableFrom(lookupClass);
}
/**
* Safe version of isInstance, returns false
* if any of the arguments is null.
*/
public static boolean isInstanceOf(Object object, Class target) {
if (object == null || target == null) {
return false;
}
return target.isInstance(object);
}
/**
* Resolves all interfaces of a type. No duplicates are returned.
* Direct interfaces are prior the interfaces of subclasses in
* the returned array.
*/
public static Class[] resolveAllInterfaces(Class type) {
Set bag = new LinkedHashSet<>();
_resolveAllInterfaces(type, bag);
return bag.toArray(new Class[bag.size()]);
}
private static void _resolveAllInterfaces(Class type, Set bag) {
// add types interfaces
Class[] interfaces = type.getInterfaces();
Collections.addAll(bag, interfaces);
// resolve interfaces of each interface
for (Class iface : interfaces) {
_resolveAllInterfaces(iface, bag);
}
// continue with super type
Class superClass = type.getSuperclass();
if (superClass == null) {
return;
}
if (superClass == Object.class) {
return;
}
_resolveAllInterfaces(type.getSuperclass(), bag);
}
/**
* Resolves all super classes, from top (direct subclass) to down. Object
* class is not included in the list.
*/
public static Class[] resolveAllSuperclasses(Class type) {
List list = new ArrayList<>();
while (true) {
type = type.getSuperclass();
if ((type == null) || (type == Object.class)) {
break;
}
list.add(type);
}
return list.toArray(new Class[list.size()]);
}
// ---------------------------------------------------------------- accessible methods
/**
* Returns array of all methods that are accessible from given class.
* @see #getAccessibleMethods(Class, Class)
*/
public static Method[] getAccessibleMethods(Class clazz) {
return getAccessibleMethods(clazz, Object.class);
}
/**
* Returns array of all methods that are accessible from given class, upto limit
* (usually Object.class). Abstract methods are ignored.
*/
public static Method[] getAccessibleMethods(Class clazz, Class limit) {
Package topPackage = clazz.getPackage();
List methodList = new ArrayList<>();
int topPackageHash = topPackage == null ? 0 : topPackage.hashCode();
boolean top = true;
do {
if (clazz == null) {
break;
}
Method[] declaredMethods = clazz.getDeclaredMethods();
for (Method method : declaredMethods) {
if (Modifier.isVolatile(method.getModifiers())) {
continue;
}
// if (Modifier.isAbstract(method.getModifiers())) {
// continue;
// }
if (top) { // add all top declared methods
methodList.add(method);
continue;
}
int modifier = method.getModifiers();
if (Modifier.isPrivate(modifier)) {
continue; // ignore super private methods
}
if (Modifier.isAbstract(modifier)) { // ignore super abstract methods
continue;
}
if (Modifier.isPublic(modifier)) {
addMethodIfNotExist(methodList, method); // add super public methods
continue;
}
if (Modifier.isProtected(modifier)) {
addMethodIfNotExist(methodList, method); // add super protected methods
continue;
}
// add super default methods from the same package
Package pckg = method.getDeclaringClass().getPackage();
int pckgHash = pckg == null ? 0 : pckg.hashCode();
if (pckgHash == topPackageHash) {
addMethodIfNotExist(methodList, method);
}
}
top = false;
} while ((clazz = clazz.getSuperclass()) != limit);
Method[] methods = new Method[methodList.size()];
for (int i = 0; i < methods.length; i++) {
methods[i] = methodList.get(i);
}
return methods;
}
private static void addMethodIfNotExist(List allMethods, Method newMethod) {
for (Method m : allMethods) {
if (compareSignatures(m, newMethod)) {
return;
}
}
allMethods.add(newMethod);
}
// ---------------------------------------------------------------- accessible fields
public static Field[] getAccessibleFields(Class clazz) {
return getAccessibleFields(clazz, Object.class);
}
public static Field[] getAccessibleFields(Class clazz, Class limit) {
Package topPackage = clazz.getPackage();
List fieldList = new ArrayList<>();
int topPackageHash = topPackage == null ? 0 : topPackage.hashCode();
boolean top = true;
do {
if (clazz == null) {
break;
}
Field[] declaredFields = clazz.getDeclaredFields();
for (Field field : declaredFields) {
if (top) { // add all top declared fields
fieldList.add(field);
continue;
}
int modifier = field.getModifiers();
if (Modifier.isPrivate(modifier)) {
continue; // ignore super private fields
}
if (Modifier.isPublic(modifier)) {
addFieldIfNotExist(fieldList, field); // add super public methods
continue;
}
if (Modifier.isProtected(modifier)) {
addFieldIfNotExist(fieldList, field); // add super protected methods
continue;
}
// add super default methods from the same package
Package pckg = field.getDeclaringClass().getPackage();
int pckgHash = pckg == null ? 0 : pckg.hashCode();
if (pckgHash == topPackageHash) {
addFieldIfNotExist(fieldList, field);
}
}
top = false;
} while ((clazz = clazz.getSuperclass()) != limit);
Field[] fields = new Field[fieldList.size()];
for (int i = 0; i < fields.length; i++) {
fields[i] = fieldList.get(i);
}
return fields;
}
private static void addFieldIfNotExist(List allFields, Field newField) {
for (Field f : allFields) {
if (compareSignatures(f, newField)) {
return;
}
}
allFields.add(newField);
}
// ---------------------------------------------------------------- supported methods
public static Method[] getSupportedMethods(Class clazz) {
return getSupportedMethods(clazz, Object.class);
}
/**
* Returns a Method array of the methods to which instances of the specified
* respond except for those methods defined in the class specified by limit
* or any of its superclasses. Note that limit is usually used to eliminate
* them methods defined by java.lang.Object. If limit is null then all
* methods are returned.
*/
public static Method[] getSupportedMethods(Class clazz, Class limit) {
ArrayList supportedMethods = new ArrayList<>();
for (Class c = clazz; c != limit; c = c.getSuperclass()) {
Method[] methods = c.getDeclaredMethods();
for (Method method : methods) {
boolean found = false;
for (Method supportedMethod : supportedMethods) {
if (compareSignatures(method, supportedMethod)) {
found = true;
break;
}
}
if (!found) {
supportedMethods.add(method);
}
}
}
return supportedMethods.toArray(new Method[supportedMethods.size()]);
}
public static Field[] getSupportedFields(Class clazz) {
return getSupportedFields(clazz, Object.class);
}
public static Field[] getSupportedFields(Class clazz, Class limit) {
ArrayList supportedFields = new ArrayList<>();
for (Class c = clazz; c != limit; c = c.getSuperclass()) {
Field[] fields = c.getDeclaredFields();
for (Field field : fields) {
boolean found = false;
for (Field supportedField : supportedFields) {
if (compareSignatures(field, supportedField)) {
found = true;
break;
}
}
if (!found) {
supportedFields.add(field);
}
}
}
return supportedFields.toArray(new Field[supportedFields.size()]);
}
// ---------------------------------------------------------------- compare
/**
* Compares method declarations: signature and return types.
*/
public static boolean compareDeclarations(Method first, Method second) {
if (first.getReturnType() != second.getReturnType()) {
return false;
}
return compareSignatures(first, second);
}
/**
* Compares method signatures: names and parameters.
*/
public static boolean compareSignatures(Method first, Method second) {
if (!first.getName().equals(second.getName())) {
return false;
}
return compareParameters(first.getParameterTypes(), second.getParameterTypes());
}
/**
* Compares constructor signatures: names and parameters.
*/
public static boolean compareSignatures(Constructor first, Constructor second) {
if (!first.getName().equals(second.getName())) {
return false;
}
return compareParameters(first.getParameterTypes(), second.getParameterTypes());
}
public static boolean compareSignatures(Field first, Field second) {
return first.getName().equals(second.getName());
}
/**
* Compares method or ctor parameters.
*/
public static boolean compareParameters(Class[] first, Class[] second) {
if (first.length != second.length) {
return false;
}
for (int i = 0; i < first.length; i++) {
if (first[i] != second[i]) {
return false;
}
}
return true;
}
// ---------------------------------------------------------------- force
/**
* Suppress access check against a reflection object. SecurityException is silently ignored.
* Checks first if the object is already accessible.
*/
public static void forceAccess(AccessibleObject accObject){
if (accObject.isAccessible()) {
return;
}
try {
accObject.setAccessible(true);
} catch (SecurityException sex) {
// ignore
}
}
// ---------------------------------------------------------------- is public
/**
* Returns true if class member is public.
*/
public static boolean isPublic(Member member) {
return Modifier.isPublic(member.getModifiers());
}
/**
* Returns true if class member is public and if its declaring class is also public.
*/
public static boolean isPublicPublic(Member member) {
if (Modifier.isPublic(member.getModifiers())) {
if (Modifier.isPublic(member.getDeclaringClass().getModifiers())) {
return true;
}
}
return false;
}
/**
* Returns true if class is public.
*/
public static boolean isPublic(Class c) {
return Modifier.isPublic(c.getModifiers());
}
// ---------------------------------------------------------------- create
/**
* Creates new instances including for common mutable classes that do not have a default constructor.
* more user-friendly. It examines if class is a map, list,
* String, Character, Boolean or a Number. Immutable instances are cached and not created again.
* Arrays are also created with no elements. Note that this bunch of if blocks
* is faster then using a HashMap.
* todo Add generics if possible
*/
public static Object newInstance(Class type) throws IllegalAccessException, InstantiationException {
if (type.isPrimitive()) {
if (type == int.class) {
return Integer.valueOf(0);
}
if (type == long.class) {
return Long.valueOf(0);
}
if (type == boolean.class) {
return Boolean.FALSE;
}
if (type == float.class) {
return Float.valueOf(0);
}
if (type == double.class) {
return Double.valueOf(0);
}
if (type == byte.class) {
return Byte.valueOf((byte) 0);
}
if (type == short.class) {
return Short.valueOf((short) 0);
}
if (type == char.class) {
return Character.valueOf((char) 0);
}
throw new IllegalArgumentException("Invalid primitive: " + type);
}
if (type == Integer.class) {
return Integer.valueOf(0);
}
if (type == String.class) {
return StringPool.EMPTY;
}
if (type == Long.class) {
return Long.valueOf(0);
}
if (type == Boolean.class) {
return Boolean.FALSE;
}
if (type == Float.class) {
return Float.valueOf(0);
}
if (type == Double.class) {
return Double.valueOf(0);
}
if (type == Map.class) {
return new HashMap();
}
if (type == List.class) {
return new ArrayList();
}
if (type == Set.class) {
return new LinkedHashSet();
}
if (type == Collection.class) {
return new ArrayList();
}
if (type == Byte.class) {
return Byte.valueOf((byte) 0);
}
if (type == Short.class) {
return Short.valueOf((short) 0);
}
if (type == Character.class) {
return Character.valueOf((char) 0);
}
if (type.isEnum()) {
return type.getEnumConstants()[0];
}
if (type.isArray()) {
return Array.newInstance(type.getComponentType(), 0);
}
return type.newInstance();
}
// ---------------------------------------------------------------- misc
/**
* Returns true if the first member is accessible from second one.
*/
public static boolean isAssignableFrom(Member member1, Member member2) {
return member1.getDeclaringClass().isAssignableFrom(member2.getDeclaringClass());
}
/**
* Returns all superclasses.
*/
public static Class[] getSuperclasses(Class type) {
int i = 0;
for (Class x = type.getSuperclass(); x != null; x = x.getSuperclass()) {
i++;
}
Class[] result = new Class[i];
i = 0;
for (Class x = type.getSuperclass(); x != null; x = x.getSuperclass()) {
result[i] = x;
i++;
}
return result;
}
/**
* Returns true if method is user defined and not defined in Object class.
*/
public static boolean isUserDefinedMethod(final Method method) {
return method.getDeclaringClass() != Object.class;
}
/**
* Returns true if method defined in Object class.
*/
public static boolean isObjectMethod(final Method method) {
return method.getDeclaringClass() == Object.class;
}
/**
* Returns true if method is a bean property.
*/
public static boolean isBeanProperty(Method method) {
if (isObjectMethod(method)) {
return false;
}
String methodName = method.getName();
Class returnType = method.getReturnType();
Class[] paramTypes = method.getParameterTypes();
if (methodName.startsWith(METHOD_GET_PREFIX)) { // getter method must starts with 'get' and it is not getClass()
if ((returnType != null) && (paramTypes.length == 0)) { // getter must have a return type and no arguments
return true;
}
} else if (methodName.startsWith(METHOD_IS_PREFIX)) { // ister must starts with 'is'
if ((returnType != null) && (paramTypes.length == 0)) { // ister must have return type and no arguments
return true;
}
} else if (methodName.startsWith(METHOD_SET_PREFIX)) { // setter must start with a 'set'
if (paramTypes.length == 1) { // setter must have just one argument
return true;
}
}
return false;
}
/**
* Returns true if method is bean getter.
*/
public static boolean isBeanPropertyGetter(Method method) {
return getBeanPropertyGetterPrefixLength(method) != 0;
}
private static int getBeanPropertyGetterPrefixLength(Method method) {
if (isObjectMethod(method)) {
return 0;
}
String methodName = method.getName();
Class returnType = method.getReturnType();
Class[] paramTypes = method.getParameterTypes();
if (methodName.startsWith(METHOD_GET_PREFIX)) { // getter method must starts with 'get' and it is not getClass()
if ((returnType != null) && (paramTypes.length == 0)) { // getter must have a return type and no arguments
return 3;
}
} else if (methodName.startsWith(METHOD_IS_PREFIX)) { // ister must starts with 'is'
if ((returnType != null) && (paramTypes.length == 0)) { // ister must have return type and no arguments
return 2;
}
}
return 0;
}
/**
* Returns property name from a getter method.
* Returns null if method is not a real getter.
*/
public static String getBeanPropertyGetterName(Method method) {
int prefixLength = getBeanPropertyGetterPrefixLength(method);
if (prefixLength == 0) {
return null;
}
String methodName = method.getName().substring(prefixLength);
return StringUtil.decapitalize(methodName);
}
/**
* Returns true if method is bean setter.
*/
public static boolean isBeanPropertySetter(Method method) {
return getBeanPropertySetterPrefixLength(method) != 0;
}
private static int getBeanPropertySetterPrefixLength(Method method) {
if (isObjectMethod(method)) {
return 0;
}
String methodName = method.getName();
Class[] paramTypes = method.getParameterTypes();
if (methodName.startsWith(METHOD_SET_PREFIX)) { // setter must start with a 'set'
if (paramTypes.length == 1) { // setter must have just one argument
return 3;
}
}
return 0;
}
/**
* Returns beans property setter name or null if method is not a real setter.
*/
public static String getBeanPropertySetterName(Method method) {
int prefixLength = getBeanPropertySetterPrefixLength(method);
if (prefixLength == 0) {
return null;
}
String methodName = method.getName().substring(prefixLength);
return StringUtil.decapitalize(methodName);
}
// ---------------------------------------------------------------- generics
/**
* Returns single component type. Index is used when type consist of many
* components. If negative, index will be calculated from the end of the
* returned array. Returns null if component type
* does not exist or if index is out of bounds.
*
* @see #getComponentTypes(java.lang.reflect.Type)
*/
public static Class getComponentType(Type type, int index) {
return getComponentType(type, null, index);
}
/**
* Returns single component type for given type and implementation.
* Index is used when type consist of many
* components. If negative, index will be calculated from the end of the
* returned array. Returns null if component type
* does not exist or if index is out of bounds.
*
*
* @see #getComponentTypes(java.lang.reflect.Type, Class)
*/
public static Class getComponentType(Type type, Class implClass, int index) {
Class[] componentTypes = getComponentTypes(type, implClass);
if (componentTypes == null) {
return null;
}
if (index < 0) {
index += componentTypes.length;
}
if (index >= componentTypes.length) {
return null;
}
return componentTypes[index];
}
/**
* @see #getComponentTypes(java.lang.reflect.Type, Class)
*/
public static Class[] getComponentTypes(Type type) {
return getComponentTypes(type, null);
}
/**
* Returns all component types of the given type.
* For example the following types all have the
* component-type MyClass:
*
* - MyClass[]
* - List<MyClass>
* - Foo<? extends MyClass>
* - Bar<? super MyClass>
* - <T extends MyClass> T[]
*
*/
public static Class[] getComponentTypes(Type type, Class implClass) {
if (type instanceof Class) {
Class clazz = (Class) type;
if (clazz.isArray()) {
return new Class[] {clazz.getComponentType()};
}
}
else if (type instanceof ParameterizedType) {
ParameterizedType pt = (ParameterizedType) type;
Type[] generics = pt.getActualTypeArguments();
if (generics.length == 0) {
return null;
}
Class[] types = new Class[generics.length];
for (int i = 0; i < generics.length; i++) {
types[i] = getRawType(generics[i], implClass);
}
return types;
}
else if (type instanceof GenericArrayType) {
GenericArrayType gat = (GenericArrayType) type;
Class rawType = getRawType(gat.getGenericComponentType(), implClass);
if (rawType == null) {
return null;
}
return new Class[] {rawType};
}
return null;
}
/**
* Shortcut for getComponentTypes(type.getGenericSuperclass()).
*
* @see #getComponentTypes(java.lang.reflect.Type)
*/
public static Class[] getGenericSupertypes(Class type) {
return getComponentTypes(type.getGenericSuperclass());
}
/**
* Shortcut for getComponentType(type.getGenericSuperclass()).
*
* @see #getComponentType(java.lang.reflect.Type, int)
*/
public static Class getGenericSupertype(Class type, int index) {
return getComponentType(type.getGenericSuperclass(), index);
}
/**
* Returns raw class for given type. Use this method with both
* regular and generic types.
*
* @param type the type to convert
* @return the closest class representing the given type
* @see #getRawType(java.lang.reflect.Type, Class)
*/
public static Class getRawType(Type type) {
return getRawType(type, null);
}
/**
* Returns raw class for given type when implementation class is known
* and it makes difference.
* @see #resolveVariable(java.lang.reflect.TypeVariable, Class)
*/
public static Class getRawType(Type type, Class implClass) {
if (type instanceof Class) {
return (Class) type;
}
if (type instanceof ParameterizedType) {
ParameterizedType pType = (ParameterizedType) type;
return getRawType(pType.getRawType(), implClass);
}
if (type instanceof WildcardType) {
WildcardType wType = (WildcardType) type;
Type[] lowerTypes = wType.getLowerBounds();
if (lowerTypes.length > 0) {
return getRawType(lowerTypes[0], implClass);
}
Type[] upperTypes = wType.getUpperBounds();
if (upperTypes.length != 0) {
return getRawType(upperTypes[0], implClass);
}
return Object.class;
}
if (type instanceof GenericArrayType) {
Type genericComponentType = ((GenericArrayType) type).getGenericComponentType();
Class rawType = getRawType(genericComponentType, implClass);
// this is sort of stupid, but there seems no other way (consider don't creating new instances each time)...
return Array.newInstance(rawType, 0).getClass();
}
if (type instanceof TypeVariable) {
TypeVariable varType = (TypeVariable) type;
if (implClass != null) {
Type resolvedType = resolveVariable(varType, implClass);
if (resolvedType != null) {
return getRawType(resolvedType, null);
}
}
Type[] boundsTypes = varType.getBounds();
if (boundsTypes.length == 0) {
return Object.class;
}
return getRawType(boundsTypes[0], implClass);
}
return null;
}
/**
* Resolves TypeVariable with given implementation class.
*/
public static Type resolveVariable(TypeVariable variable, final Class implClass) {
final Class rawType = getRawType(implClass, null);
int index = ArraysUtil.indexOf(rawType.getTypeParameters(), variable);
if (index >= 0) {
return variable;
}
final Class[] interfaces = rawType.getInterfaces();
final Type[] genericInterfaces = rawType.getGenericInterfaces();
for (int i = 0; i <= interfaces.length; i++) {
Class rawInterface;
if (i < interfaces.length) {
rawInterface = interfaces[i];
} else {
rawInterface = rawType.getSuperclass();
if (rawInterface == null) {
continue;
}
}
final Type resolved = resolveVariable(variable, rawInterface);
if (resolved instanceof Class || resolved instanceof ParameterizedType) {
return resolved;
}
if (resolved instanceof TypeVariable) {
final TypeVariable typeVariable = (TypeVariable) resolved;
index = ArraysUtil.indexOf(rawInterface.getTypeParameters(), typeVariable);
if (index < 0) {
throw new IllegalArgumentException("Invalid type variable:" + typeVariable);
}
final Type type = i < genericInterfaces.length ? genericInterfaces[i] : rawType.getGenericSuperclass();
if (type instanceof Class) {
return Object.class;
}
if (type instanceof ParameterizedType) {
return ((ParameterizedType) type).getActualTypeArguments()[index];
}
throw new IllegalArgumentException("Unsupported type: " + type);
}
}
return null;
}
/**
* Converts Type to a String. Supports successor interfaces:
*
* java.lang.Class - represents usual classjava.lang.reflect.ParameterizedType - class with generic parameter (e.g. List)java.lang.reflect.TypeVariable - generic type literal (e.g. List, T - type variable)java.lang.reflect.WildcardType - wildcard type (List<? extends Number>, "? extends Number - wildcard type)java.lang.reflect.GenericArrayType - type for generic array (e.g. T[], T - array type)
*/
public static String typeToString(Type type) {
StringBuilder sb = new StringBuilder();
typeToString(sb, type, new HashSet());
return sb.toString();
}
private static void typeToString(StringBuilder sb, Type type, Set visited) {
if (type instanceof ParameterizedType) {
ParameterizedType parameterizedType = (ParameterizedType) type;
final Class rawType = (Class) parameterizedType.getRawType();
sb.append(rawType.getName());
boolean first = true;
for (Type typeArg : parameterizedType.getActualTypeArguments()) {
if (first) {
first = false;
} else {
sb.append(", ");
}
sb.append('<');
typeToString(sb, typeArg, visited);
sb.append('>');
}
} else if (type instanceof WildcardType) {
WildcardType wildcardType = (WildcardType) type;
sb.append('?');
// According to JLS(http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.5.1):
// - Lower and upper can't coexist: (for instance, this is not allowed: & super MyInterface>)
// - Multiple bounds are not supported (for instance, this is not allowed: & MyInterface>)
final Type bound;
if (wildcardType.getLowerBounds().length != 0) {
sb.append(" super ");
bound = wildcardType.getLowerBounds()[0];
} else {
sb.append(" extends ");
bound = wildcardType.getUpperBounds()[0];
}
typeToString(sb, bound, visited);
} else if (type instanceof TypeVariable) {
TypeVariable typeVariable = (TypeVariable) type;
sb.append(typeVariable.getName());
// prevent cycles in case: >
if (!visited.contains(type)) {
visited.add(type);
sb.append(" extends ");
boolean first = true;
for (Type bound : typeVariable.getBounds()) {
if (first) {
first = false;
} else {
sb.append(" & ");
}
typeToString(sb, bound, visited);
}
visited.remove(type);
}
} else if (type instanceof GenericArrayType) {
GenericArrayType genericArrayType = (GenericArrayType) type;
typeToString(genericArrayType.getGenericComponentType());
sb.append(genericArrayType.getGenericComponentType());
sb.append("[]");
} else if (type instanceof Class) {
Class typeClass = (Class) type;
sb.append(typeClass.getName());
} else {
throw new IllegalArgumentException("Unsupported type: " + type);
}
}
// ---------------------------------------------------------------- annotations
/**
* Reads annotation value. Returns null on error
* (e.g. when value name not found).
*/
public static Object readAnnotationValue(Annotation annotation, String name) {
try {
Method method = annotation.annotationType().getDeclaredMethod(name);
return method.invoke(annotation);
} catch (Exception ignore) {
return null;
}
}
// ---------------------------------------------------------------- caller
private static class ReflectUtilSecurityManager extends SecurityManager {
public Class getCallerClass(int callStackDepth) {
return getClassContext()[callStackDepth + 1];
}
}
private static ReflectUtilSecurityManager SECURITY_MANAGER;
static {
try {
SECURITY_MANAGER = new ReflectUtilSecurityManager();
} catch (Exception ex) {
SECURITY_MANAGER = null;
}
}
/**
* Emulates Reflection.getCallerClass using standard API.
* This implementation uses custom SecurityManager
* and it is the fastest. Other implementations are:
*
* new Throwable().getStackTrace()[callStackDepth]Thread.currentThread().getStackTrace()[callStackDepth] (the slowest)
*
* In case when usage of SecurityManager is not allowed,
* this method fails back to the second implementation.
*
* Note that original Reflection.getCallerClass is way faster
* then any emulation.
*/
public static Class getCallerClass(int framesToSkip) {
if (SECURITY_MANAGER != null) {
return SECURITY_MANAGER.getCallerClass(framesToSkip);
}
StackTraceElement[] stackTraceElements = new Throwable().getStackTrace();
if (framesToSkip >= 2) {
framesToSkip += 4;
}
String className = stackTraceElements[framesToSkip].getClassName();
try {
return Thread.currentThread().getContextClassLoader().loadClass(className);
} catch (ClassNotFoundException cnfex) {
throw new UnsupportedOperationException(className + " not found.");
}
}
/**
* Smart variant of {@link #getCallerClass(int)} that skips all relevant Jodd calls.
* However, this one does not use the security manager.
*/
public static Class getCallerClass() {
String className = null;
StackTraceElement[] stackTraceElements = new Throwable().getStackTrace();
for (StackTraceElement stackTraceElement : stackTraceElements) {
className = stackTraceElement.getClassName();
String methodName = stackTraceElement.getMethodName();
if (methodName.equals("loadClass")) {
if (className.contains(ClassLoaderStrategy.class.getSimpleName())) {
continue;
}
if (className.equals(ClassLoaderUtil.class.getName())) {
continue;
}
} else if (methodName.equals("getCallerClass")) {
continue;
}
break;
}
try {
return Thread.currentThread().getContextClassLoader().loadClass(className);
} catch (ClassNotFoundException cnfex) {
throw new UnsupportedOperationException(className + " not found.");
}
}
// ---------------------------------------------------------------- enum
/**
* Returns enum class or null if class is not an enum.
*/
public static Class findEnum(Class target) {
if (target.isPrimitive()) {
return null;
}
while (target != Object.class) {
if (target.isEnum()) {
return target;
}
target = target.getSuperclass();
}
return null;
}
}
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