Issue
After initializing context like this in my spring project :
AnnotationConfigApplicationContext context =
new AnnotationConfigApplicationContext();
after that I've tried to refresh the config file before calling "getBean()" :
context.refresh(); // explicit refresh of the config file.
and then :
ICustomerDal customerDal
= context.getBean("database", ICustomerDal.class);
customerDal.add();
But in the end I've got the "NoSuchBeanDefinitionException: No bean named 'database' available" error.
ICustomerDal.class File :
package com.springdemo;
public interface ICustomerDal {
void add();
}
MySqlCustomerDal.class File :
package com.springdemo;
import org.springframework.stereotype.Component;
@Component("database")
public class MySqlCustomerDal implements ICustomerDal {
String connectionString;
// Getter
public String getConnectionString() {
return connectionString;
}
// Setter
public void setConnectionString(String connectionString) {
this.connectionString = connectionString;
}
@Override
public void add() {
System.out.println("Connection String : " + this.connectionString);
System.out.println("Added to MySQL Database!"); // MySQL Codes.
}
}
IocConfig.class File:
package com.springdemo;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@Configuration
@ComponentScan("com.springdemo")
public class IocConfig {
}
But if I do it like the code block below, there is no error :
AnnotationConfigApplicationContext context =
new AnnotationConfigApplicationContext("com.springdemo"); // implicitly registering and refreshing config file.
ICustomerDal customerDal = context.getBean("database", ICustomerDal.class);
customerDal.add();
I just couldn't understand that if I get "NoSuchBeanDefinitionException" in the first scenario, how come I get no error just after passing the package name in ApplicationContext parameter?
Thank you in advance for your precious thoughts.
Solution
For anyone who could encounter the same issue here :
Actually I have managed to comprehend and solve the situation here.
I realized that I need to specify the config file either in ApplicationContext or manually by registering.
Also we can specify the config file like this for another bonus method :
new AnnotationConfigApplicationContext(IocConfig.class); // Specifying the exact class name rather than the package name itself.
And using the code below helped me for another method instead of passing a parameter into "AnnotationConfigApplicationContext" :
context.register(IocConfig.class); // --> To specify the config file.
context.refresh(); // --> Need to explicitly refresh the config file after registering.
Answered By - velihan
Answer Checked By - David Goodson (JavaFixing Volunteer)
