I have the solution:
make a new class that implements Converter
then add this method
List<String> result = new ArrayList<String>();
for (String part : source.split("[\n\t:;,]")) {
if (!part.trim().isEmpty()) {
result.add(part.trim());
}
}
return result;
then add this to the spring servlet:
<mvc:annotation-driven conversion-service="conversionService"/>
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<list>
<bean class="YOUR.PACKAGE.TextAreaSetConverter" />
</list>
</property>
</bean>