/*
* Copyright 2002-2009 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.core.convert.support;
import java.io.StringWriter;
import java.util.Collections;
import java.util.Set;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.core.convert.converter.ConditionalGenericConverter;
/**
* Simply calls {@link Object#toString()} to convert any supported Object to a String.
* Supports Number, Boolean, Character, CharSequence, StringWriter, any enum,
* and any class with a String constructor or <code>valueOf(String)</code> method.
*
* <p>Used by the default ConversionService as a fallback if there are no other explicit
* to-String converters registered.
*
* @author Keith Donald
* @author Juergen Hoeller
* @since 3.0
*/
final class ObjectToStringConverter implements ConditionalGenericConverter {
public Set<ConvertiblePair> getConvertibleTypes() {
return Collections.singleton(new ConvertiblePair(Object.class, String.class));
}
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
Class<?> sourceClass = sourceType.getObjectType();
return CharSequence.class.isAssignableFrom(sourceClass) || Number.class.isAssignableFrom(sourceClass) ||
Boolean.class.equals(sourceClass) || Character.class.equals(sourceClass) || StringWriter.class.isAssignableFrom(sourceClass) ||
sourceClass.isEnum() || ObjectToObjectConverter.hasValueOfMethodOrConstructor(sourceClass, String.class);
}
public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
return (source != null ? source.toString() : null);
}
}
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