Perché DataSource non può essere avviato automaticamente nell'applicazione di avvio di primavera?

Question

So che avvio la primavera creerà una Bean dataSource automaticamente se le configurazioni relative si trovano in application.properties, come:

spring.datasource.url = jdbc:mysql://192.168.10.103:3306/hms?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull 
spring.datasource.username=root 
spring.datasource.password=test@123 
spring.datasource.driver-class-name=com.mysql.jdbc.Driver 

Codice funzione:

package com.synline.mdataserver; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.boot.CommandLineRunner; 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 
import org.springframework.context.annotation.AnnotationConfigApplicationContext; 
import org.apache.tomcat.jdbc.pool.DataSource; 

@SpringBootApplication 
public class Application implements CommandLineRunner { 

    @Autowired 
    AnnotationConfigApplicationContext context; 

    /*@Autowired 
    DataSource dataSource;*/ 

    public static void main(String[] args) throws InterruptedException { 
     SpringApplication.run(Application.class, args); 
    } 

    @Override 
    public void run(String... args) throws Exception { 
     DataSource dataSource = (DataSource)context.getBean("dataSource"); 
     System.out.println(dataSource); 

     while (true) { 
      Thread.sleep(5000); 
     } 

    } 
} 

Se il @Autowired DataSource è commentata, la Le informazioni sul bean saranno stampate:

org.apache.tomcat.jdbc.pool.DataSource@1800a575{ConnectionPool[defaultAutoCommit=null; defaultReadOnly=null; ....} 

Quindi penso che Spring Boot reall hai creato il fagiolo.

Ma se si usa @Autowried DataSource, un'eccezione si verifica a lamentarsi No Such Bean

Error creating bean with name 'application': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: org.apache.tomcat.jdbc.pool.DataSource com.synline.mdataserver.Application.dataSource; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.apache.tomcat.jdbc.pool.DataSource] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} 

Answer 1

La variabile deve essere dichiarata come JDBC DataSource standard (vale a dire javax.sql.DataSource), non come una particolare implementazione di tale interfaccia.