Constructor dependency Injection issue - spring

Question

I am learning DI and new to spring while trying out CI I have written following code and I think I am correct in syntax still it's showing bean creation error. why it is unable to create bean..??
The code is
Constuctor.java
package beans;
public class Constructor {
private String name;
private int age;
private String email;
public void Constructor(String name, int age, String email){
this.name=name;
this.age=age;
this.email=email;
}
public void show()
{
System.out.println("Name = "+name);
System.out.println("Age = "+age);
System.out.println("Email = "+email);
}
}
spring.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"
"http://www.springframework.org/dtd/spring-beans-2.0.dtd">
<!-- Ordered parameters -->
<beans>
<bean id="t" class="beans.Constructor">
<constructor-arg value="Alok"/>
<constructor-arg value="24"/>
<constructor-arg value="alok#gmail.com"/>
</bean>
</beans>
Const_main.java
package test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import beans.Constructor;
public class Const_main {
public static void main(String[] args) {
ApplicationContext ap= new ClassPathXmlApplicationContext("resources/spring.xml");
Constructor c = (Constructor)ap.getBean("t");
c.show();
}
}
it's giving the following error
Jun 29, 2017 3:16:45 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext#b1a58a3: startup date [Thu Jun 29 15:16:45 IST 2017]; root of context hierarchy
Jun 29, 2017 3:16:45 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resources/spring.xml]
Jun 29, 2017 3:16:46 PM org.springframework.context.support.ClassPathXmlApplicationContext refresh
WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: **Error creating bean with name 't' defined in class path resource [resources/spring.xml]: Could not resolve matching constructor (hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)
Exception in thread "main"** org.springframework.beans.factory.BeanCreationException: Error creating bean with name 't' defined in class path resource [resources/spring.xml]: Could not resolve matching constructor (hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:240)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at test.Const_main.main(Const_main.java:10)

Answer 1

Try this way
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"
"http://www.springframework.org/dtd/spring-beans-2.0.dtd">
<!-- Ordered parameters -->
<beans>
<bean id="t" class="beans.Constructor">
<constructor-arg>
<value>Alok</value>
</constructor-arg>
<constructor-arg>
<value>24</value>
</constructor-arg>
<constructor-arg>
<value>alok#gmail.com</value>
</constructor-arg>
</bean>
</beans>

Answer 2

You are trying to use Constructor Dependency Injection without creating any such constructor in your DTO (Constructor.java)
The method you defined above:
public void Constructor(String name, int age, String email){
this.name=name;
this.age=age;
this.email=email;
}
is just a simple method/function not a constructor, try to remove the word void.
Note:
To remove any ambiguities for constructor matching, it is more prefer to use indexes with constructor's parameters like:
<bean id="t" class="beans.Constructor">
<constructor-arg value="Alok" index="0"/>
<constructor-arg value="24" index="1"/>
<constructor-arg value="alok#gmail.com" index="2"/>
</bean>