Spring trim all input field

<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
    <property name="converters">
        <list>
            <bean class="sample.convertor.StringToTrimmedStringConverter"/>
        </list>
    </property>
</bean>

<mvc:annotation-driven conversion-service="conversionService"/>

package sample.convertor;

import org.springframework.core.convert.converter.Converter;

public class StringToTrimmedStringConverter implements
        Converter<String, String> {

    public String convert(String s) {
        return null == s ? null : s.trim();
    }

}