my ConversionService encountered 500 error code - spring-mvc

Question

I am learning the spring mvc and when i try to use the ConversionService ,i encounterrd 500
#RequestMapping("/handle81")
public String handle81(#RequestParam("user")User user,ModelMap modelMap) {
System.out.println(user);
modelMap.put("user", user);
return "/user/success";
}
this is the handler method ,i've put the #RequestMapping("/user") at the class
and the converter
public class StringToUserConverter implements Converter<String, User> {
public User convert(String source) {
System.out.println(source);
User user=new User();
String[] item=source.split(":");
user.setUserName(item[0]);
user.setPassword(item[1]);
user.setName(item[2]);
return user;
}
}
<mvc:annotation-driven conversion-service="conversionService" />
<bean id="conversionService"
class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<list>
<bean class="com.baobaotao.domain.StringToUserConverter" />
</list>
</property>
</bean>
so when i browse
http://localhost:8080/spring-mvc/user/handle81.html?user=asdf:asdf:fdas
it gets 500 and prints nothing at the console(i use maven-jetty to do the test)
thx for helping~

Answer 1

I think your Request URL may not be not matching. You specify "/handle81" in the annotation, but are requesting "/handle81.html".
It's hard to tell, without further information, whether the problem is matching & dispatching the request to the handler; or in the conversion.
Try another handler with the parameter of type String, and see whether you can call that successfully. At least you'll then know where the problem is.
And what is the exception stack-trace? Why didn't you post it? That's your most important clue & you should always post the ex message & top few lines/ where it was thrown, when you ask a question. It should be in either the application or Tomcat/ other server logs.