org.springframework.beans.BeanUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2023 the original author or authors.
*
* 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
*
* https://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.springframework.beans;
import java.beans.ConstructorProperties;
import java.beans.PropertyDescriptor;
import java.beans.PropertyEditor;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import kotlin.jvm.JvmClassMappingKt;
import kotlin.jvm.JvmInline;
import kotlin.reflect.KClass;
import kotlin.reflect.KFunction;
import kotlin.reflect.KParameter;
import kotlin.reflect.full.KAnnotatedElements;
import kotlin.reflect.full.KClasses;
import kotlin.reflect.jvm.KCallablesJvm;
import kotlin.reflect.jvm.ReflectJvmMapping;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.KotlinDetector;
import org.springframework.core.MethodParameter;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.core.ResolvableType;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ConcurrentReferenceHashMap;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
/**
* Static convenience methods for JavaBeans: for instantiating beans,
* checking bean property types, copying bean properties, etc.
*
* Mainly for internal use within the framework, but to some degree also
* useful for application classes. Consider
* Apache Commons BeanUtils,
* BULL - Bean Utils Light Library,
* or similar third-party frameworks for more comprehensive bean utilities.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @author Rob Harrop
* @author Sam Brannen
* @author Sebastien Deleuze
*/
public abstract class BeanUtils {
private static final ParameterNameDiscoverer parameterNameDiscoverer =
new DefaultParameterNameDiscoverer();
private static final Set> unknownEditorTypes =
Collections.newSetFromMap(new ConcurrentReferenceHashMap<>(64));
private static final Map, Object> DEFAULT_TYPE_VALUES = Map.of(
boolean.class, false,
byte.class, (byte) 0,
short.class, (short) 0,
int.class, 0,
long.class, 0L,
float.class, 0F,
double.class, 0D,
char.class, '\0');
/**
* Convenience method to instantiate a class using its no-arg constructor.
* @param clazz class to instantiate
* @return the new instance
* @throws BeanInstantiationException if the bean cannot be instantiated
* @see Class#newInstance()
* @deprecated as of Spring 5.0, following the deprecation of
* {@link Class#newInstance()} in JDK 9
*/
@Deprecated
public static T instantiate(Class clazz) throws BeanInstantiationException {
Assert.notNull(clazz, "Class must not be null");
if (clazz.isInterface()) {
throw new BeanInstantiationException(clazz, "Specified class is an interface");
}
try {
return clazz.newInstance();
}
catch (InstantiationException ex) {
throw new BeanInstantiationException(clazz, "Is it an abstract class?", ex);
}
catch (IllegalAccessException ex) {
throw new BeanInstantiationException(clazz, "Is the constructor accessible?", ex);
}
}
/**
* Instantiate a class using its 'primary' constructor (for Kotlin classes,
* potentially having default arguments declared) or its default constructor
* (for regular Java classes, expecting a standard no-arg setup).
* Note that this method tries to set the constructor accessible
* if given a non-accessible (that is, non-public) constructor.
* @param clazz the class to instantiate
* @return the new instance
* @throws BeanInstantiationException if the bean cannot be instantiated.
* The cause may notably indicate a {@link NoSuchMethodException} if no
* primary/default constructor was found, a {@link NoClassDefFoundError}
* or other {@link LinkageError} in case of an unresolvable class definition
* (e.g. due to a missing dependency at runtime), or an exception thrown
* from the constructor invocation itself.
* @see Constructor#newInstance
*/
public static T instantiateClass(Class clazz) throws BeanInstantiationException {
Assert.notNull(clazz, "Class must not be null");
if (clazz.isInterface()) {
throw new BeanInstantiationException(clazz, "Specified class is an interface");
}
Constructor ctor;
try {
ctor = clazz.getDeclaredConstructor();
}
catch (NoSuchMethodException ex) {
ctor = findPrimaryConstructor(clazz);
if (ctor == null) {
throw new BeanInstantiationException(clazz, "No default constructor found", ex);
}
}
catch (LinkageError err) {
throw new BeanInstantiationException(clazz, "Unresolvable class definition", err);
}
return instantiateClass(ctor);
}
/**
* Instantiate a class using its no-arg constructor and return the new instance
* as the specified assignable type.
* Useful in cases where the type of the class to instantiate (clazz) is not
* available, but the type desired (assignableTo) is known.
*
Note that this method tries to set the constructor accessible if given a
* non-accessible (that is, non-public) constructor.
* @param clazz class to instantiate
* @param assignableTo type that clazz must be assignableTo
* @return the new instance
* @throws BeanInstantiationException if the bean cannot be instantiated
* @see Constructor#newInstance
*/
@SuppressWarnings("unchecked")
public static T instantiateClass(Class clazz, Class assignableTo) throws BeanInstantiationException {
Assert.isAssignable(assignableTo, clazz);
return (T) instantiateClass(clazz);
}
/**
* Convenience method to instantiate a class using the given constructor.
* Note that this method tries to set the constructor accessible if given a
* non-accessible (that is, non-public) constructor, and supports Kotlin classes
* with optional parameters and default values.
* @param ctor the constructor to instantiate
* @param args the constructor arguments to apply (use {@code null} for an unspecified
* parameter, Kotlin optional parameters and Java primitive types are supported)
* @return the new instance
* @throws BeanInstantiationException if the bean cannot be instantiated
* @see Constructor#newInstance
*/
public static T instantiateClass(Constructor ctor, Object... args) throws BeanInstantiationException {
Assert.notNull(ctor, "Constructor must not be null");
try {
ReflectionUtils.makeAccessible(ctor);
if (KotlinDetector.isKotlinReflectPresent() && KotlinDetector.isKotlinType(ctor.getDeclaringClass())) {
return KotlinDelegate.instantiateClass(ctor, args);
}
else {
int parameterCount = ctor.getParameterCount();
Assert.isTrue(args.length <= parameterCount, "Can't specify more arguments than constructor parameters");
if (parameterCount == 0) {
return ctor.newInstance();
}
Class[] parameterTypes = ctor.getParameterTypes();
Object[] argsWithDefaultValues = new Object[args.length];
for (int i = 0 ; i < args.length; i++) {
if (args[i] == null) {
Class parameterType = parameterTypes[i];
argsWithDefaultValues[i] = (parameterType.isPrimitive() ? DEFAULT_TYPE_VALUES.get(parameterType) : null);
}
else {
argsWithDefaultValues[i] = args[i];
}
}
return ctor.newInstance(argsWithDefaultValues);
}
}
catch (InstantiationException ex) {
throw new BeanInstantiationException(ctor, "Is it an abstract class?", ex);
}
catch (IllegalAccessException ex) {
throw new BeanInstantiationException(ctor, "Is the constructor accessible?", ex);
}
catch (IllegalArgumentException ex) {
throw new BeanInstantiationException(ctor, "Illegal arguments for constructor", ex);
}
catch (InvocationTargetException ex) {
throw new BeanInstantiationException(ctor, "Constructor threw exception", ex.getTargetException());
}
}
/**
* Return a resolvable constructor for the provided class, either a primary or single
* public constructor with arguments, or a single non-public constructor with arguments,
* or simply a default constructor. Callers have to be prepared to resolve arguments
* for the returned constructor's parameters, if any.
* @param clazz the class to check
* @throws IllegalStateException in case of no unique constructor found at all
* @since 5.3
* @see #findPrimaryConstructor
*/
@SuppressWarnings("unchecked")
public static Constructor getResolvableConstructor(Class clazz) {
Constructor ctor = findPrimaryConstructor(clazz);
if (ctor != null) {
return ctor;
}
Constructor[] ctors = clazz.getConstructors();
if (ctors.length == 1) {
// A single public constructor
return (Constructor) ctors[0];
}
else if (ctors.length == 0) {
// No public constructors -> check non-public
ctors = clazz.getDeclaredConstructors();
if (ctors.length == 1) {
// A single non-public constructor, e.g. from a non-public record type
return (Constructor) ctors[0];
}
}
// Several constructors -> let's try to take the default constructor
try {
return clazz.getDeclaredConstructor();
}
catch (NoSuchMethodException ex) {
// Giving up...
}
// No unique constructor at all
throw new IllegalStateException("No primary or single unique constructor found for " + clazz);
}
/**
* Return the primary constructor of the provided class. For Kotlin classes, this
* returns the Java constructor corresponding to the Kotlin primary constructor
* (as defined in the Kotlin specification). Otherwise, in particular for non-Kotlin
* classes, this simply returns {@code null}.
* @param clazz the class to check
* @since 5.0
* @see Kotlin docs
*/
@Nullable
public static Constructor findPrimaryConstructor(Class clazz) {
Assert.notNull(clazz, "Class must not be null");
if (KotlinDetector.isKotlinReflectPresent() && KotlinDetector.isKotlinType(clazz)) {
return KotlinDelegate.findPrimaryConstructor(clazz);
}
return null;
}
/**
* Find a method with the given method name and the given parameter types,
* declared on the given class or one of its superclasses. Prefers public methods,
* but will return a protected, package access, or private method too.
* Checks {@code Class.getMethod} first, falling back to
* {@code findDeclaredMethod}. This allows to find public methods
* without issues even in environments with restricted Java security settings.
* @param clazz the class to check
* @param methodName the name of the method to find
* @param paramTypes the parameter types of the method to find
* @return the Method object, or {@code null} if not found
* @see Class#getMethod
* @see #findDeclaredMethod
*/
@Nullable
public static Method findMethod(Class clazz, String methodName, Class... paramTypes) {
try {
return clazz.getMethod(methodName, paramTypes);
}
catch (NoSuchMethodException ex) {
return findDeclaredMethod(clazz, methodName, paramTypes);
}
}
/**
* Find a method with the given method name and the given parameter types,
* declared on the given class or one of its superclasses. Will return a public,
* protected, package access, or private method.
*
Checks {@code Class.getDeclaredMethod}, cascading upwards to all superclasses.
* @param clazz the class to check
* @param methodName the name of the method to find
* @param paramTypes the parameter types of the method to find
* @return the Method object, or {@code null} if not found
* @see Class#getDeclaredMethod
*/
@Nullable
public static Method findDeclaredMethod(Class clazz, String methodName, Class... paramTypes) {
try {
return clazz.getDeclaredMethod(methodName, paramTypes);
}
catch (NoSuchMethodException ex) {
if (clazz.getSuperclass() != null) {
return findDeclaredMethod(clazz.getSuperclass(), methodName, paramTypes);
}
return null;
}
}
/**
* Find a method with the given method name and minimal parameters (best case: none),
* declared on the given class or one of its superclasses. Prefers public methods,
* but will return a protected, package access, or private method too.
*
Checks {@code Class.getMethods} first, falling back to
* {@code findDeclaredMethodWithMinimalParameters}. This allows for finding public
* methods without issues even in environments with restricted Java security settings.
* @param clazz the class to check
* @param methodName the name of the method to find
* @return the Method object, or {@code null} if not found
* @throws IllegalArgumentException if methods of the given name were found but
* could not be resolved to a unique method with minimal parameters
* @see Class#getMethods
* @see #findDeclaredMethodWithMinimalParameters
*/
@Nullable
public static Method findMethodWithMinimalParameters(Class clazz, String methodName)
throws IllegalArgumentException {
Method targetMethod = findMethodWithMinimalParameters(clazz.getMethods(), methodName);
if (targetMethod == null) {
targetMethod = findDeclaredMethodWithMinimalParameters(clazz, methodName);
}
return targetMethod;
}
/**
* Find a method with the given method name and minimal parameters (best case: none),
* declared on the given class or one of its superclasses. Will return a public,
* protected, package access, or private method.
*
Checks {@code Class.getDeclaredMethods}, cascading upwards to all superclasses.
* @param clazz the class to check
* @param methodName the name of the method to find
* @return the Method object, or {@code null} if not found
* @throws IllegalArgumentException if methods of the given name were found but
* could not be resolved to a unique method with minimal parameters
* @see Class#getDeclaredMethods
*/
@Nullable
public static Method findDeclaredMethodWithMinimalParameters(Class clazz, String methodName)
throws IllegalArgumentException {
Method targetMethod = findMethodWithMinimalParameters(clazz.getDeclaredMethods(), methodName);
if (targetMethod == null && clazz.getSuperclass() != null) {
targetMethod = findDeclaredMethodWithMinimalParameters(clazz.getSuperclass(), methodName);
}
return targetMethod;
}
/**
* Find a method with the given method name and minimal parameters (best case: none)
* in the given list of methods.
* @param methods the methods to check
* @param methodName the name of the method to find
* @return the Method object, or {@code null} if not found
* @throws IllegalArgumentException if methods of the given name were found but
* could not be resolved to a unique method with minimal parameters
*/
@Nullable
public static Method findMethodWithMinimalParameters(Method[] methods, String methodName)
throws IllegalArgumentException {
Method targetMethod = null;
int numMethodsFoundWithCurrentMinimumArgs = 0;
for (Method method : methods) {
if (method.getName().equals(methodName)) {
int numParams = method.getParameterCount();
if (targetMethod == null || numParams < targetMethod.getParameterCount()) {
targetMethod = method;
numMethodsFoundWithCurrentMinimumArgs = 1;
}
else if (!method.isBridge() && targetMethod.getParameterCount() == numParams) {
if (targetMethod.isBridge()) {
// Prefer regular method over bridge...
targetMethod = method;
}
else {
// Additional candidate with same length
numMethodsFoundWithCurrentMinimumArgs++;
}
}
}
}
if (numMethodsFoundWithCurrentMinimumArgs > 1) {
throw new IllegalArgumentException("Cannot resolve method '" + methodName +
"' to a unique method. Attempted to resolve to overloaded method with " +
"the least number of parameters but there were " +
numMethodsFoundWithCurrentMinimumArgs + " candidates.");
}
return targetMethod;
}
/**
* Parse a method signature in the form {@code methodName[([arg_list])]},
* where {@code arg_list} is an optional, comma-separated list of fully-qualified
* type names, and attempts to resolve that signature against the supplied {@code Class}.
*
When not supplying an argument list ({@code methodName}) the method whose name
* matches and has the least number of parameters will be returned. When supplying an
* argument type list, only the method whose name and argument types match will be returned.
*
Note then that {@code methodName} and {@code methodName()} are not
* resolved in the same way. The signature {@code methodName} means the method called
* {@code methodName} with the least number of arguments, whereas {@code methodName()}
* means the method called {@code methodName} with exactly 0 arguments.
*
If no method can be found, then {@code null} is returned.
* @param signature the method signature as String representation
* @param clazz the class to resolve the method signature against
* @return the resolved Method
* @see #findMethod
* @see #findMethodWithMinimalParameters
*/
@Nullable
public static Method resolveSignature(String signature, Class clazz) {
Assert.hasText(signature, "'signature' must not be empty");
Assert.notNull(clazz, "Class must not be null");
int startParen = signature.indexOf('(');
int endParen = signature.indexOf(')');
if (startParen > -1 && endParen == -1) {
throw new IllegalArgumentException("Invalid method signature '" + signature +
"': expected closing ')' for args list");
}
else if (startParen == -1 && endParen > -1) {
throw new IllegalArgumentException("Invalid method signature '" + signature +
"': expected opening '(' for args list");
}
else if (startParen == -1) {
return findMethodWithMinimalParameters(clazz, signature);
}
else {
String methodName = signature.substring(0, startParen);
String[] parameterTypeNames =
StringUtils.commaDelimitedListToStringArray(signature.substring(startParen + 1, endParen));
Class[] parameterTypes = new Class[parameterTypeNames.length];
for (int i = 0; i < parameterTypeNames.length; i++) {
String parameterTypeName = parameterTypeNames[i].trim();
try {
parameterTypes[i] = ClassUtils.forName(parameterTypeName, clazz.getClassLoader());
}
catch (Throwable ex) {
throw new IllegalArgumentException("Invalid method signature: unable to resolve type [" +
parameterTypeName + "] for argument " + i + ". Root cause: " + ex);
}
}
return findMethod(clazz, methodName, parameterTypes);
}
}
/**
* Retrieve the JavaBeans {@code PropertyDescriptor}s of a given class.
* @param clazz the Class to retrieve the PropertyDescriptors for
* @return an array of {@code PropertyDescriptors} for the given class
* @throws BeansException if PropertyDescriptor look fails
*/
public static PropertyDescriptor[] getPropertyDescriptors(Class clazz) throws BeansException {
return CachedIntrospectionResults.forClass(clazz).getPropertyDescriptors();
}
/**
* Retrieve the JavaBeans {@code PropertyDescriptors} for the given property.
* @param clazz the Class to retrieve the PropertyDescriptor for
* @param propertyName the name of the property
* @return the corresponding PropertyDescriptor, or {@code null} if none
* @throws BeansException if PropertyDescriptor lookup fails
*/
@Nullable
public static PropertyDescriptor getPropertyDescriptor(Class clazz, String propertyName) throws BeansException {
return CachedIntrospectionResults.forClass(clazz).getPropertyDescriptor(propertyName);
}
/**
* Find a JavaBeans {@code PropertyDescriptor} for the given method,
* with the method either being the read method or the write method for
* that bean property.
* @param method the method to find a corresponding PropertyDescriptor for,
* introspecting its declaring class
* @return the corresponding PropertyDescriptor, or {@code null} if none
* @throws BeansException if PropertyDescriptor lookup fails
*/
@Nullable
public static PropertyDescriptor findPropertyForMethod(Method method) throws BeansException {
return findPropertyForMethod(method, method.getDeclaringClass());
}
/**
* Find a JavaBeans {@code PropertyDescriptor} for the given method,
* with the method either being the read method or the write method for
* that bean property.
* @param method the method to find a corresponding PropertyDescriptor for
* @param clazz the (most specific) class to introspect for descriptors
* @return the corresponding PropertyDescriptor, or {@code null} if none
* @throws BeansException if PropertyDescriptor lookup fails
* @since 3.2.13
*/
@Nullable
public static PropertyDescriptor findPropertyForMethod(Method method, Class clazz) throws BeansException {
Assert.notNull(method, "Method must not be null");
PropertyDescriptor[] pds = getPropertyDescriptors(clazz);
for (PropertyDescriptor pd : pds) {
if (method.equals(pd.getReadMethod()) || method.equals(pd.getWriteMethod())) {
return pd;
}
}
return null;
}
/**
* Find a JavaBeans PropertyEditor following the 'Editor' suffix convention
* (e.g. "mypackage.MyDomainClass" → "mypackage.MyDomainClassEditor").
*
Compatible to the standard JavaBeans convention as implemented by
* {@link java.beans.PropertyEditorManager} but isolated from the latter's
* registered default editors for primitive types.
* @param targetType the type to find an editor for
* @return the corresponding editor, or {@code null} if none found
*/
@Nullable
public static PropertyEditor findEditorByConvention(@Nullable Class targetType) {
if (targetType == null || targetType.isArray() || unknownEditorTypes.contains(targetType)) {
return null;
}
ClassLoader cl = targetType.getClassLoader();
if (cl == null) {
try {
cl = ClassLoader.getSystemClassLoader();
if (cl == null) {
return null;
}
}
catch (Throwable ex) {
// e.g. AccessControlException on Google App Engine
return null;
}
}
String targetTypeName = targetType.getName();
String editorName = targetTypeName + "Editor";
try {
Class editorClass = cl.loadClass(editorName);
if (editorClass != null) {
if (!PropertyEditor.class.isAssignableFrom(editorClass)) {
unknownEditorTypes.add(targetType);
return null;
}
return (PropertyEditor) instantiateClass(editorClass);
}
// Misbehaving ClassLoader returned null instead of ClassNotFoundException
// - fall back to unknown editor type registration below
}
catch (ClassNotFoundException ex) {
// Ignore - fall back to unknown editor type registration below
}
unknownEditorTypes.add(targetType);
return null;
}
/**
* Determine the bean property type for the given property from the
* given classes/interfaces, if possible.
* @param propertyName the name of the bean property
* @param beanClasses the classes to check against
* @return the property type, or {@code Object.class} as fallback
*/
public static Class findPropertyType(String propertyName, @Nullable Class... beanClasses) {
if (beanClasses != null) {
for (Class beanClass : beanClasses) {
PropertyDescriptor pd = getPropertyDescriptor(beanClass, propertyName);
if (pd != null) {
return pd.getPropertyType();
}
}
}
return Object.class;
}
/**
* Obtain a new MethodParameter object for the write method of the
* specified property.
* @param pd the PropertyDescriptor for the property
* @return a corresponding MethodParameter object
*/
public static MethodParameter getWriteMethodParameter(PropertyDescriptor pd) {
if (pd instanceof GenericTypeAwarePropertyDescriptor gpd) {
return new MethodParameter(gpd.getWriteMethodParameter());
}
else {
Method writeMethod = pd.getWriteMethod();
Assert.state(writeMethod != null, "No write method available");
return new MethodParameter(writeMethod, 0);
}
}
/**
* Determine required parameter names for the given constructor,
* considering the JavaBeans {@link ConstructorProperties} annotation
* as well as Spring's {@link DefaultParameterNameDiscoverer}.
* @param ctor the constructor to find parameter names for
* @return the parameter names (matching the constructor's parameter count)
* @throws IllegalStateException if the parameter names are not resolvable
* @since 5.3
* @see ConstructorProperties
* @see DefaultParameterNameDiscoverer
*/
public static String[] getParameterNames(Constructor ctor) {
ConstructorProperties cp = ctor.getAnnotation(ConstructorProperties.class);
String[] paramNames = (cp != null ? cp.value() : parameterNameDiscoverer.getParameterNames(ctor));
Assert.state(paramNames != null, () -> "Cannot resolve parameter names for constructor " + ctor);
Assert.state(paramNames.length == ctor.getParameterCount(),
() -> "Invalid number of parameter names: " + paramNames.length + " for constructor " + ctor);
return paramNames;
}
/**
* Check if the given type represents a "simple" property: a simple value
* type or an array of simple value types.
*
See {@link #isSimpleValueType(Class)} for the definition of simple
* value type.
*
Used to determine properties to check for a "simple" dependency-check.
* @param type the type to check
* @return whether the given type represents a "simple" property
* @see org.springframework.beans.factory.support.RootBeanDefinition#DEPENDENCY_CHECK_SIMPLE
* @see org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#checkDependencies
* @see #isSimpleValueType(Class)
*/
public static boolean isSimpleProperty(Class type) {
Assert.notNull(type, "'type' must not be null");
return isSimpleValueType(type) || (type.isArray() && isSimpleValueType(type.componentType()));
}
/**
* Check if the given type represents a "simple" value type for
* bean property and data binding purposes:
* a primitive or primitive wrapper, an {@code Enum}, a {@code String}
* or other {@code CharSequence}, a {@code Number}, a {@code Date},
* a {@code Temporal}, a {@code UUID}, a {@code URI}, a {@code URL},
* a {@code Locale}, or a {@code Class}.
*
{@code Void} and {@code void} are not considered simple value types.
*
As of 6.1, this method delegates to {@link ClassUtils#isSimpleValueType}
* as-is but could potentially add further rules for bean property purposes.
* @param type the type to check
* @return whether the given type represents a "simple" value type
* @see #isSimpleProperty(Class)
* @see ClassUtils#isSimpleValueType(Class)
*/
public static boolean isSimpleValueType(Class type) {
return ClassUtils.isSimpleValueType(type);
}
/**
* Copy the property values of the given source bean into the target bean.
*
Note: The source and target classes do not have to match or even be derived
* from each other, as long as the properties match. Any bean properties that the
* source bean exposes but the target bean does not will silently be ignored.
*
This is just a convenience method. For more complex transfer needs,
* consider using a full {@link BeanWrapper}.
*
As of Spring Framework 5.3, this method honors generic type information
* when matching properties in the source and target objects.
*
The following table provides a non-exhaustive set of examples of source
* and target property types that can be copied as well as source and target
* property types that cannot be copied.
*
* source property type target property type copy supported {@code Integer} {@code Integer} yes {@code Integer} {@code Number} yes {@code List} {@code List} yes {@code List} {@code List} yes {@code List} {@code List} yes {@code List} {@code List} yes {@code String} {@code Integer} no {@code Number} {@code Integer} no {@code List} {@code List} no {@code List} {@code List} no
* @param source the source bean
* @param target the target bean
* @throws BeansException if the copying failed
* @see BeanWrapper
*/
public static void copyProperties(Object source, Object target) throws BeansException {
copyProperties(source, target, null, (String[]) null);
}
/**
* Copy the property values of the given source bean into the given target bean,
* only setting properties defined in the given "editable" class (or interface).
* Note: The source and target classes do not have to match or even be derived
* from each other, as long as the properties match. Any bean properties that the
* source bean exposes but the target bean does not will silently be ignored.
*
This is just a convenience method. For more complex transfer needs,
* consider using a full {@link BeanWrapper}.
*
As of Spring Framework 5.3, this method honors generic type information
* when matching properties in the source and target objects. See the
* documentation for {@link #copyProperties(Object, Object)} for details.
* @param source the source bean
* @param target the target bean
* @param editable the class (or interface) to restrict property setting to
* @throws BeansException if the copying failed
* @see BeanWrapper
*/
public static void copyProperties(Object source, Object target, Class editable) throws BeansException {
copyProperties(source, target, editable, (String[]) null);
}
/**
* Copy the property values of the given source bean into the given target bean,
* ignoring the given "ignoreProperties".
*
Note: The source and target classes do not have to match or even be derived
* from each other, as long as the properties match. Any bean properties that the
* source bean exposes but the target bean does not will silently be ignored.
*
This is just a convenience method. For more complex transfer needs,
* consider using a full {@link BeanWrapper}.
*
As of Spring Framework 5.3, this method honors generic type information
* when matching properties in the source and target objects. See the
* documentation for {@link #copyProperties(Object, Object)} for details.
* @param source the source bean
* @param target the target bean
* @param ignoreProperties array of property names to ignore
* @throws BeansException if the copying failed
* @see BeanWrapper
*/
public static void copyProperties(Object source, Object target, String... ignoreProperties) throws BeansException {
copyProperties(source, target, null, ignoreProperties);
}
/**
* Copy the property values of the given source bean into the given target bean.
*
Note: The source and target classes do not have to match or even be derived
* from each other, as long as the properties match. Any bean properties that the
* source bean exposes but the target bean does not will silently be ignored.
*
As of Spring Framework 5.3, this method honors generic type information
* when matching properties in the source and target objects. See the
* documentation for {@link #copyProperties(Object, Object)} for details.
* @param source the source bean
* @param target the target bean
* @param editable the class (or interface) to restrict property setting to
* @param ignoreProperties array of property names to ignore
* @throws BeansException if the copying failed
* @see BeanWrapper
*/
private static void copyProperties(Object source, Object target, @Nullable Class editable,
@Nullable String... ignoreProperties) throws BeansException {
Assert.notNull(source, "Source must not be null");
Assert.notNull(target, "Target must not be null");
Class actualEditable = target.getClass();
if (editable != null) {
if (!editable.isInstance(target)) {
throw new IllegalArgumentException("Target class [" + target.getClass().getName() +
"] not assignable to editable class [" + editable.getName() + "]");
}
actualEditable = editable;
}
PropertyDescriptor[] targetPds = getPropertyDescriptors(actualEditable);
Set ignoredProps = (ignoreProperties != null ? new HashSet<>(Arrays.asList(ignoreProperties)) : null);
CachedIntrospectionResults sourceResults = (actualEditable != source.getClass() ?
CachedIntrospectionResults.forClass(source.getClass()) : null);
for (PropertyDescriptor targetPd : targetPds) {
Method writeMethod = targetPd.getWriteMethod();
if (writeMethod != null && (ignoredProps == null || !ignoredProps.contains(targetPd.getName()))) {
PropertyDescriptor sourcePd = (sourceResults != null ?
sourceResults.getPropertyDescriptor(targetPd.getName()) : targetPd);
if (sourcePd != null) {
Method readMethod = sourcePd.getReadMethod();
if (readMethod != null) {
if (isAssignable(writeMethod, readMethod, sourcePd, targetPd)) {
try {
ReflectionUtils.makeAccessible(readMethod);
Object value = readMethod.invoke(source);
ReflectionUtils.makeAccessible(writeMethod);
writeMethod.invoke(target, value);
}
catch (Throwable ex) {
throw new FatalBeanException(
"Could not copy property '" + targetPd.getName() + "' from source to target", ex);
}
}
}
}
}
}
}
private static boolean isAssignable(Method writeMethod, Method readMethod,
PropertyDescriptor sourcePd, PropertyDescriptor targetPd) {
Type paramType = writeMethod.getGenericParameterTypes()[0];
if (paramType instanceof Class clazz) {
return ClassUtils.isAssignable(clazz, readMethod.getReturnType());
}
else if (paramType.equals(readMethod.getGenericReturnType())) {
return true;
}
else {
ResolvableType sourceType = ((GenericTypeAwarePropertyDescriptor) sourcePd).getReadMethodType();
ResolvableType targetType = ((GenericTypeAwarePropertyDescriptor) targetPd).getWriteMethodType();
// Ignore generic types in assignable check if either ResolvableType has unresolvable generics.
return (sourceType.hasUnresolvableGenerics() || targetType.hasUnresolvableGenerics() ?
ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], readMethod.getReturnType()) :
targetType.isAssignableFrom(sourceType));
}
}
/**
* Inner class to avoid a hard dependency on Kotlin at runtime.
*/
private static class KotlinDelegate {
/**
* Retrieve the Java constructor corresponding to the Kotlin primary constructor, if any.
* @param clazz the {@link Class} of the Kotlin class
* @see
* https://kotlinlang.org/docs/reference/classes.html#constructors
*/
@SuppressWarnings("unchecked")
@Nullable
public static Constructor findPrimaryConstructor(Class clazz) {
try {
KClass kClass = JvmClassMappingKt.getKotlinClass(clazz);
KFunction primaryCtor = KClasses.getPrimaryConstructor(kClass);
if (primaryCtor == null) {
return null;
}
if (kClass.isValue() && !KAnnotatedElements
.findAnnotations(kClass, JvmClassMappingKt.getKotlinClass(JvmInline.class)).isEmpty()) {
Constructor[] constructors = clazz.getDeclaredConstructors();
Assert.state(constructors.length == 1,
"Kotlin value classes annotated with @JvmInline are expected to have a single JVM constructor");
return (Constructor) constructors[0];
}
Constructor constructor = ReflectJvmMapping.getJavaConstructor(primaryCtor);
if (constructor == null) {
throw new IllegalStateException(
"Failed to find Java constructor for Kotlin primary constructor: " + clazz.getName());
}
return constructor;
}
catch (UnsupportedOperationException ex) {
return null;
}
}
/**
* Instantiate a Kotlin class using the provided constructor.
* @param ctor the constructor of the Kotlin class to instantiate
* @param args the constructor arguments to apply
* (use {@code null} for unspecified parameter if needed)
*/
public static T instantiateClass(Constructor ctor, Object... args)
throws IllegalAccessException, InvocationTargetException, InstantiationException {
KFunction kotlinConstructor = ReflectJvmMapping.getKotlinFunction(ctor);
if (kotlinConstructor == null) {
return ctor.newInstance(args);
}
if ((!Modifier.isPublic(ctor.getModifiers()) || !Modifier.isPublic(ctor.getDeclaringClass().getModifiers()))) {
KCallablesJvm.setAccessible(kotlinConstructor, true);
}
List parameters = kotlinConstructor.getParameters();
Assert.isTrue(args.length <= parameters.size(),
"Number of provided arguments must be less than or equal to the number of constructor parameters");
if (parameters.isEmpty()) {
return kotlinConstructor.call();
}
Map argParameters = CollectionUtils.newHashMap(parameters.size());
for (int i = 0 ; i < args.length ; i++) {
if (!(parameters.get(i).isOptional() && args[i] == null)) {
argParameters.put(parameters.get(i), args[i]);
}
}
return kotlinConstructor.callBy(argParameters);
}
}
}