2019年2月11日 星期一

深入淺出SpringBoot Chapter3.2 裝配你的Bean

代碼清單3-5 User.java

package com.springboot.chapter3.config;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import lombok.Data;

@Component("user")
public @Data class User {
 @Value("1")
 private Long id;
 @Value("user_name_1")
 private String userName;
 @Value("note_1")
 private String note;
}

代碼清單3-6 Appconfig.java
package com.springboot.chapter3.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@Configuration
@ComponentScan
public class Appconfig {
 
}

代碼清單3-7 IoCTest.java
package com.springboot.chapter3.config;
import org.apache.log4j.Logger;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class IoCTest {
 private static Logger log = Logger.getLogger(IoCTest.class);
 public static void main(String[] args) {
  ApplicationContext ctx =
    new AnnotationConfigApplicationContext(Appconfig.class);
  User user = ctx.getBean(User.class);
  log.info(user);
 }
}

執行結果



把User.java 移到 package com.spring.chapter3.pojo 
package com.springboot.chapter3.pojo;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import lombok.Data;

@Component("user")
public @Data class User {
 @Value("1")
 private Long id;
 @Value("user_name_1")
 private String userName;
 @Value("note_1")
 private String note;
}

改變componentScan的位置
package com.springboot.chapter3.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@Configuration
//可以wildcat
//@ComponentScan("com.springboot.chapter3.*")
@ComponentScan("com.springboot.chapter3.pojo")
public class Appconfig {
 
}



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