/* * Copyright 2002-2013 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.beans; import java.lang.reflect.Field; import org.springframework.core.MethodParameter; /** * Interface that defines type conversion methods. Typically (but not necessarily) * implemented in conjunction with the {@link PropertyEditorRegistry} interface. * * <p><b>Note:</b> Since TypeConverter implementations are typically based on * {@link java.beans.PropertyEditor PropertyEditors} which aren't thread-safe, * TypeConverters themselves are <em>not</em> to be considered as thread-safe either. * * @author Juergen Hoeller * @since 2.0 * @see SimpleTypeConverter * @see BeanWrapperImpl */ public interface TypeConverter { /** * Convert the value to the required type (if necessary from a String). * <p>Conversions from String to any type will typically use the {@code setAsText} * method of the PropertyEditor class, or a Spring Converter in a ConversionService. * @param value the value to convert * @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 TypeMismatchException if type conversion failed * @see java.beans.PropertyEditor#setAsText(String) * @see java.beans.PropertyEditor#getValue() * @see org.springframework.core.convert.ConversionService * @see org.springframework.core.convert.converter.Converter */ <T> T convertIfNecessary(Object value, Class<T> requiredType) throws TypeMismatchException; /** * Convert the value to the required type (if necessary from a String). * <p>Conversions from String to any type will typically use the {@code setAsText} * method of the PropertyEditor class, or a Spring Converter in a ConversionService. * @param value the value to convert * @param requiredType the type we must convert to * (or {@code null} if not known, for example in case of a collection element) * @param methodParam the method parameter that is the target of the conversion * (for analysis of generic types; may be {@code null}) * @return the new value, possibly the result of type conversion * @throws TypeMismatchException if type conversion failed * @see java.beans.PropertyEditor#setAsText(String) * @see java.beans.PropertyEditor#getValue() * @see org.springframework.core.convert.ConversionService * @see org.springframework.core.convert.converter.Converter */ <T> T convertIfNecessary(Object value, Class<T> requiredType, MethodParameter methodParam) throws TypeMismatchException; /** * Convert the value to the required type (if necessary from a String). * <p>Conversions from String to any type will typically use the {@code setAsText} * method of the PropertyEditor class, or a Spring Converter in a ConversionService. * @param value the value to convert * @param requiredType the type we must convert to * (or {@code null} if not known, for example in case of a collection element) * @param field the reflective field that is the target of the conversion * (for analysis of generic types; may be {@code null}) * @return the new value, possibly the result of type conversion * @throws TypeMismatchException if type conversion failed * @see java.beans.PropertyEditor#setAsText(String) * @see java.beans.PropertyEditor#getValue() * @see org.springframework.core.convert.ConversionService * @see org.springframework.core.convert.converter.Converter */ <T> T convertIfNecessary(Object value, Class<T> requiredType, Field field) throws TypeMismatchException; }