Is it really mandatory to give bean an id - spring

Question

I thought naming a bean with id is not mandatory before i get stuck here.
dispatcher-servlet.xml
<mvc:annotation-driven />
<context:annotation-config />
<context:component-scan
base-package="com.springMVC.*"></context:component-scan>
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/Views/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
<bean id="messageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename">
<value>/WEB-INF/messagekeys</value>
</property>
</bean>
messagekeys.properties
NotEmpty.user1.name = UserName cannot be empty
Size.user1.name = Name should have a length between 6 and 16
Pattern.user1.name = Name should not contain numeric value
Min.user1.age = Age cannot be less than 12
Max.user1.age = Age cannot be more than 60
NotNull.user1.age = Please enter your age
NotEmpty.user1.email = email cannot be left blank
Email.user1.email = email is not valid
NotEmpty.user1.country = Enter valid country
User.java
package com.springMVC.model;
import javax.validation.constraints.Email;
import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
#Component
#Scope("request")
public class User {
#NotEmpty
#Size(min=6,max=16)
#Pattern(regexp = "[^0-9]+")
private String name;
#Min(value=12)
#Max(value=60)
#NotNull
private Integer age;
#NotEmpty
#Email
private String email;
#NotEmpty
private String country;
public void setName(String name) {
this.name = name;
}
public void setAge(Integer age) {
this.age = age;
}
public void setEmail(String email) {
this.email = email;
}
public void setCountry(String country) {
this.country = country;
}
public String getName() {
return name;
}
public Integer getAge() {
return age;
}
public String getEmail() {
return email;
}
public String getCountry() {
return country;
}
}
When i use the bean InternalResourceViewResolver without bean id, it works fine.
But when i use the bean ReloadableResourceBundleMessageSource without bean id, it doesn't render error messages from messages.properties
When i give ReloadableResourceBundleMessageSource bean an id, it works perfect.
So, my question is Is naming a bean with an id mandatory?
Thanks in advance :)

Answer 1

Yes for message resource
When an ApplicationContext is loaded, it automatically searches for a MessageSource bean defined in the context. The bean must have the name messageSource. If such a bean is found, all calls to the preceding methods are delegated to the message source. If no message source is found, the ApplicationContext attempts to find a parent containing a bean with the same name. If it does, it uses that bean as the MessageSource. If the ApplicationContext cannot find any source for messages, an empty DelegatingMessageSource is instantiated in order to be able to accept calls to the methods defined above.
check here documentation