infra.beans.TypeConverterDelegate Maven / Gradle / Ivy
/*
* Copyright 2017 - 2024 the original author or authors.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [https://www.gnu.org/licenses/]
*/
package infra.beans;
import java.beans.PropertyEditor;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Optional;
import infra.core.TypeDescriptor;
import infra.core.conversion.ConversionFailedException;
import infra.core.conversion.ConversionService;
import infra.lang.Nullable;
import infra.logging.Logger;
import infra.logging.LoggerFactory;
import infra.util.ClassUtils;
import infra.util.CollectionUtils;
import infra.util.NumberUtils;
import infra.util.ReflectionUtils;
import infra.util.StringUtils;
/**
* Internal helper class for converting property values to target types.
*
* Works on a given {@link PropertyEditorRegistrySupport} instance.
* Used as a delegate by {@link BeanWrapperImpl} and {@link SimpleTypeConverter}.
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Dave Syer
* @author Harry Yang
* @see BeanWrapperImpl
* @see SimpleTypeConverter
* @since 4.0 2022/2/17 17:46
*/
public class TypeConverterDelegate {
private static final Logger logger = LoggerFactory.getLogger(TypeConverterDelegate.class);
private final PropertyEditorRegistrySupport propertyEditorRegistry;
@Nullable
private final Object targetObject;
/**
* Create a new TypeConverterDelegate for the given editor registry.
*
* @param propertyEditorRegistry the editor registry to use
*/
public TypeConverterDelegate(PropertyEditorRegistrySupport propertyEditorRegistry) {
this(propertyEditorRegistry, null);
}
/**
* Create a new TypeConverterDelegate for the given editor registry and bean instance.
*
* @param propertyEditorRegistry the editor registry to use
* @param targetObject the target object to work on (as context that can be passed to editors)
*/
public TypeConverterDelegate(PropertyEditorRegistrySupport propertyEditorRegistry, @Nullable Object targetObject) {
this.propertyEditorRegistry = propertyEditorRegistry;
this.targetObject = targetObject;
}
/**
* Convert the value to the required type for the specified property.
*
* @param propertyName name of the property
* @param oldValue the previous value, if available (may be {@code null})
* @param newValue the proposed new value
* @param requiredType the type we must convert to
* (or {@code null} if not known, for example in case of a collection element)
* @return the new value, possibly the result of type conversion
* @throws IllegalArgumentException if type conversion failed
*/
@Nullable
public T convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue,
Object newValue, @Nullable Class requiredType) throws IllegalArgumentException {
return convertIfNecessary(propertyName, oldValue, newValue, requiredType, TypeDescriptor.valueOf(requiredType));
}
/**
* Convert the value to the required type (if necessary from a String),
* for the specified property.
*
* @param propertyName name of the property
* @param oldValue the previous value, if available (may be {@code null})
* @param newValue the proposed new value
* @param requiredType the type we must convert to
* (or {@code null} if not known, for example in case of a collection element)
* @param typeDescriptor the descriptor for the target property or field
* @return the new value, possibly the result of type conversion
* @throws IllegalArgumentException if type conversion failed
*/
@SuppressWarnings("unchecked")
@Nullable
public T convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue, @Nullable Object newValue,
@Nullable Class requiredType, @Nullable TypeDescriptor typeDescriptor) throws IllegalArgumentException {
ConversionFailedException conversionAttemptEx = null;
// Custom editor for this type?
PropertyEditor editor = propertyEditorRegistry.findCustomEditor(requiredType, propertyName);
// No custom editor but custom ConversionService specified?
ConversionService conversionService = propertyEditorRegistry.getConversionService();
if (editor == null && conversionService != null && newValue != null && typeDescriptor != null) {
TypeDescriptor sourceTypeDesc = TypeDescriptor.forObject(newValue);
if (conversionService.canConvert(sourceTypeDesc, typeDescriptor)) {
try {
return (T) conversionService.convert(newValue, sourceTypeDesc, typeDescriptor);
}
catch (ConversionFailedException ex) {
// fallback to default conversion logic below
conversionAttemptEx = ex;
}
}
}
Object convertedValue = newValue;
// Value not of required type?
if (editor != null || (requiredType != null && !ClassUtils.isAssignableValue(requiredType, convertedValue))) {
if (typeDescriptor != null
&& requiredType != null
&& Collection.class.isAssignableFrom(requiredType)) {
TypeDescriptor elementTypeDesc = typeDescriptor.getElementDescriptor();
if (elementTypeDesc != null) {
Class elementType = elementTypeDesc.getType();
if (convertedValue instanceof String text) {
if (Class.class == elementType || Enum.class.isAssignableFrom(elementType)) {
convertedValue = StringUtils.commaDelimitedListToStringArray(text);
}
if (editor == null && String.class != elementType) {
editor = findDefaultEditor(elementType.arrayType());
}
}
}
}
if (editor == null) {
editor = findDefaultEditor(requiredType);
}
convertedValue = doConvertValue(oldValue, convertedValue, requiredType, editor);
}
boolean standardConversion = false;
if (requiredType != null) {
// Try to apply some standard type conversion rules if appropriate.
if (convertedValue != null) {
if (Object.class == requiredType) {
return (T) convertedValue;
}
else if (requiredType.isArray()) {
// Array required -> apply appropriate conversion of elements.
if (convertedValue instanceof String && Enum.class.isAssignableFrom(requiredType.getComponentType())) {
convertedValue = StringUtils.commaDelimitedListToStringArray((String) convertedValue);
}
return (T) convertToTypedArray(convertedValue, propertyName, requiredType.getComponentType());
}
else if (convertedValue.getClass().isArray()) {
if (Collection.class.isAssignableFrom(requiredType)) {
convertedValue = convertToTypedCollection(CollectionUtils.arrayToList(convertedValue),
propertyName, requiredType, typeDescriptor);
standardConversion = true;
}
else if (Array.getLength(convertedValue) == 1) {
convertedValue = Array.get(convertedValue, 0);
standardConversion = true;
}
}
else if (convertedValue instanceof Collection) {
// Convert elements to target type, if determined.
convertedValue = convertToTypedCollection(
(Collection) convertedValue, propertyName, requiredType, typeDescriptor);
standardConversion = true;
}
else if (convertedValue instanceof Map) {
// Convert keys and values to respective target type, if determined.
convertedValue = convertToTypedMap(
(Map) convertedValue, propertyName, requiredType, typeDescriptor);
standardConversion = true;
}
if (String.class == requiredType && ClassUtils.isPrimitiveOrWrapper(convertedValue.getClass())) {
// We can stringify any primitive value...
return (T) convertedValue.toString();
}
else if (convertedValue instanceof String && !requiredType.isInstance(convertedValue)) {
if (conversionAttemptEx == null && !requiredType.isInterface() && !requiredType.isEnum()) {
try {
Constructor strCtor = requiredType.getConstructor(String.class);
return BeanUtils.newInstance(strCtor, convertedValue);
}
catch (NoSuchMethodException ex) {
// proceed with field lookup
if (logger.isTraceEnabled()) {
logger.trace("No String constructor found on type [{}]", requiredType.getName(), ex);
}
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("Construction via String failed for type [{}]", requiredType.getName(), ex);
}
}
}
String trimmedValue = ((String) convertedValue).trim();
if (requiredType.isEnum() && trimmedValue.isEmpty()) {
// It's an empty enum identifier: reset the enum value to null.
return null;
}
convertedValue = attemptToConvertStringToEnum(requiredType, trimmedValue, convertedValue);
standardConversion = true;
}
else if (convertedValue instanceof Number && Number.class.isAssignableFrom(requiredType)) {
convertedValue = NumberUtils.convertNumberToTargetClass(
(Number) convertedValue, (Class) requiredType);
standardConversion = true;
}
}
else {
// convertedValue == null
if (requiredType == Optional.class) {
convertedValue = Optional.empty();
}
}
if (!ClassUtils.isAssignableValue(requiredType, convertedValue)) {
if (conversionAttemptEx != null) {
// Original exception from former ConversionService call above...
throw conversionAttemptEx;
}
else if (conversionService != null && typeDescriptor != null) {
// ConversionService not tried before, probably custom editor found
// but editor couldn't produce the required type...
TypeDescriptor sourceTypeDesc = TypeDescriptor.forObject(newValue);
if (conversionService.canConvert(sourceTypeDesc, typeDescriptor)) {
return (T) conversionService.convert(newValue, sourceTypeDesc, typeDescriptor);
}
}
// Definitely doesn't match: throw IllegalArgumentException/IllegalStateException
StringBuilder msg = new StringBuilder();
msg.append("Cannot convert value of type '").append(ClassUtils.getDescriptiveType(newValue));
msg.append("' to required type '").append(ClassUtils.getQualifiedName(requiredType)).append('\'');
if (propertyName != null) {
msg.append(" for property '").append(propertyName).append('\'');
}
if (editor != null) {
msg.append(": PropertyEditor [").append(editor.getClass().getName()).append(
"] returned inappropriate value of type '").append(
ClassUtils.getDescriptiveType(convertedValue)).append('\'');
throw new IllegalArgumentException(msg.toString());
}
else {
msg.append(": no matching editors or conversion strategy found");
throw new IllegalStateException(msg.toString());
}
}
}
if (conversionAttemptEx != null) {
if (editor == null && !standardConversion && requiredType != null && Object.class != requiredType) {
throw conversionAttemptEx;
}
if (logger.isDebugEnabled()) {
logger.debug("Original ConversionService attempt failed - ignored since " +
"PropertyEditor based conversion eventually succeeded", conversionAttemptEx);
}
}
return (T) convertedValue;
}
private Object attemptToConvertStringToEnum(Class requiredType, String trimmedValue, Object currentConvertedValue) {
Object convertedValue = currentConvertedValue;
if (Enum.class == requiredType && this.targetObject != null) {
// target type is declared as raw enum, treat the trimmed value as .FIELD_NAME
int index = trimmedValue.lastIndexOf('.');
if (index > -1) {
String enumType = trimmedValue.substring(0, index);
String fieldName = trimmedValue.substring(index + 1);
ClassLoader cl = this.targetObject.getClass().getClassLoader();
try {
Class enumValueType = ClassUtils.forName(enumType, cl);
Field enumField = enumValueType.getField(fieldName);
convertedValue = enumField.get(null);
}
catch (ClassNotFoundException ex) {
if (logger.isTraceEnabled()) {
logger.trace("Enum class [{}] cannot be loaded", enumType, ex);
}
}
catch (Throwable ex) {
if (logger.isTraceEnabled()) {
logger.trace("Field [{}] isn't an enum value for type [{}]", fieldName, enumType, ex);
}
}
}
}
if (convertedValue == currentConvertedValue) {
// Try field lookup as fallback: for JDK 1.5 enum or custom enum
// with values defined as static fields. Resulting value still needs
// to be checked, hence we don't return it right away.
try {
Field enumField = requiredType.getField(trimmedValue);
ReflectionUtils.makeAccessible(enumField);
convertedValue = enumField.get(null);
}
catch (Throwable ex) {
if (logger.isTraceEnabled()) {
logger.trace("Field [{}] isn't an enum value", convertedValue, ex);
}
}
}
return convertedValue;
}
/**
* Find a default editor for the given type.
*
* @param requiredType the type to find an editor for
* @return the corresponding editor, or {@code null} if none
*/
@Nullable
private PropertyEditor findDefaultEditor(@Nullable Class requiredType) {
PropertyEditor editor = null;
if (requiredType != null) {
// No custom editor -> check BeanWrapperImpl's default editors.
editor = this.propertyEditorRegistry.getDefaultEditor(requiredType);
if (editor == null && String.class != requiredType) {
// No BeanWrapper default editor -> check standard JavaBean editor.
editor = BeanUtils.findEditorByConvention(requiredType);
}
}
return editor;
}
/**
* Convert the value to the required type (if necessary from a String),
* using the given property editor.
*
* @param oldValue the previous value, if available (may be {@code null})
* @param newValue the proposed new value
* @param requiredType the type we must convert to
* (or {@code null} if not known, for example in case of a collection element)
* @param editor the PropertyEditor to use
* @return the new value, possibly the result of type conversion
* @throws IllegalArgumentException if type conversion failed
*/
@Nullable
private Object doConvertValue(@Nullable Object oldValue, @Nullable Object newValue,
@Nullable Class requiredType, @Nullable PropertyEditor editor) {
Object convertedValue = newValue;
if (editor != null && !(convertedValue instanceof String)) {
// Not a String -> use PropertyEditor's setValue.
// With standard PropertyEditors, this will return the very same object;
// we just want to allow special PropertyEditors to override setValue
// for type conversion from non-String values to the required type.
try {
editor.setValue(convertedValue);
Object newConvertedValue = editor.getValue();
if (newConvertedValue != convertedValue) {
convertedValue = newConvertedValue;
// Reset PropertyEditor: It already did a proper conversion.
// Don't use it again for a setAsText call.
editor = null;
}
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("PropertyEditor [{}] does not support setValue call", editor.getClass().getName(), ex);
}
// Swallow and proceed.
}
}
Object returnValue = convertedValue;
if (requiredType != null && !requiredType.isArray() && convertedValue instanceof String[]) {
// Convert String array to a comma-separated String.
// Only applies if no PropertyEditor converted the String array before.
// The CSV String will be passed into a PropertyEditor's setAsText method, if any.
if (logger.isTraceEnabled()) {
logger.trace("Converting String array to comma-delimited String [{}]", convertedValue);
}
convertedValue = StringUtils.arrayToCommaDelimitedString((String[]) convertedValue);
}
if (convertedValue instanceof String) {
if (editor != null) {
// Use PropertyEditor's setAsText in case of a String value.
if (logger.isTraceEnabled()) {
logger.trace("Converting String to [{}] using property editor [{}]", requiredType, editor);
}
return doConvertTextValue(oldValue, (String) convertedValue, editor);
}
else if (String.class == requiredType) {
returnValue = convertedValue;
}
}
return returnValue;
}
/**
* Convert the given text value using the given property editor.
*
* @param oldValue the previous value, if available (may be {@code null})
* @param newTextValue the proposed text value
* @param editor the PropertyEditor to use
* @return the converted value
*/
private Object doConvertTextValue(@Nullable Object oldValue, String newTextValue, PropertyEditor editor) {
try {
editor.setValue(oldValue);
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("PropertyEditor [{}] does not support setValue call", editor.getClass().getName(), ex);
}
// Swallow and proceed.
}
editor.setAsText(newTextValue);
return editor.getValue();
}
private Object convertToTypedArray(Object input, @Nullable String propertyName, Class componentType) {
if (input instanceof Collection coll) {
// Convert Collection elements to array elements.
Object result = Array.newInstance(componentType, coll.size());
int i = 0;
for (Iterator it = coll.iterator(); it.hasNext(); i++) {
Object value = convertIfNecessary(
buildIndexedPropertyName(propertyName, i), null, it.next(), componentType);
Array.set(result, i, value);
}
return result;
}
else if (input.getClass().isArray()) {
// Convert array elements, if necessary.
if (componentType.equals(input.getClass().getComponentType())
&& !this.propertyEditorRegistry.hasCustomEditorForElement(componentType, propertyName)) {
return input;
}
int arrayLength = Array.getLength(input);
Object result = Array.newInstance(componentType, arrayLength);
for (int i = 0; i < arrayLength; i++) {
Object value = convertIfNecessary(
buildIndexedPropertyName(propertyName, i), null, Array.get(input, i), componentType);
Array.set(result, i, value);
}
return result;
}
else {
// A plain value: convert it to an array with a single component.
Object result = Array.newInstance(componentType, 1);
Object value = convertIfNecessary(
buildIndexedPropertyName(propertyName, 0), null, input, componentType);
Array.set(result, 0, value);
return result;
}
}
private Collection convertToTypedCollection(Collection original, @Nullable String propertyName,
Class requiredType, @Nullable TypeDescriptor typeDescriptor) {
if (!Collection.class.isAssignableFrom(requiredType)) {
return original;
}
boolean approximable = CollectionUtils.isApproximableCollectionType(requiredType);
if (!approximable && cannotCreateCopy(requiredType)) {
if (logger.isDebugEnabled()) {
logger.debug("Custom Collection type [{}] does not allow for creating a copy - injecting original Collection as-is",
classNameOf(original));
}
return original;
}
boolean originalAllowed = requiredType.isInstance(original);
TypeDescriptor elementType = typeDescriptor != null ? typeDescriptor.getElementDescriptor() : null;
if (elementType == null && originalAllowed
&& !this.propertyEditorRegistry.hasCustomEditorForElement(null, propertyName)) {
return original;
}
Iterator it;
try {
it = original.iterator();
}
catch (Throwable ex) {
if (logger.isDebugEnabled()) {
logger.debug("Cannot access Collection of type [{}] - injecting original Collection as-is: {}",
classNameOf(original), ex.toString());
}
return original;
}
Collection