《Spring In Action》学习笔记之HelloWorld

Spring有很多优点：轻量级，非侵入性，面向切面，容器，框架

我们是用spring核心包之BeanFactory构造最经典的helloWorld

接口隔离开来

package HelloWorld;

public interface GreetingHelloworld ...{
   public void sayHelloworld();
}

 实现类：

使用spring的IOC依赖注入机制，两种方式：设值注入（成员变量）和构造注入（构造函数参数）

 

package HelloWorld;

public class GreetingHelloworldImpl implements GreetingHelloworld ...{
   private String greetingText;
   private String greetingFromConstructor;
   public GreetingHelloworldImpl(String greetingFromConstructor)...{
       this.greetingFromConstructor=greetingFromConstructor;
   }
   public GreetingHelloworldImpl()...{
       
   }
    public String getGreetingText() ...{
       return greetingText;
   }
    public void setGreetingText(String greetingText) ...{
    this.greetingText = greetingText;
    }
    public void sayHelloworld() ...{
       System.out.println(this.getGreetingText());
       System.out.println(this.getGreetingFromConstructor());
    }
    public String getGreetingFromConstructor() ...{
        return greetingFromConstructor;
    }
    public void setGreetingFromConstructor(String greetingFromConstructor) ...{
        this.greetingFromConstructor = greetingFromConstructor;
    }

}

 

spring配置文件：

 

 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd" >
<beans>
 <bean id="greeting" class="HelloWorld.GreetingHelloworldImpl">
   <constructor-arg>
      <value>this is helloworld from construtor</value>
   </constructor-arg>
   <property name="greetingText">
     <value>hello world!</value>
   </property>
   
 </bean>
</beans>

 

测试用例：

 

package HelloWorld;

import java.io.File;
import java.net.URISyntaxException;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;



public class TestHelloWorld ...{

    public static void main(String[] args) ...{

        String filePath=System.getProperty("user.dir")+File.separator+"HelloWorld"+File.separator+"hello.xml";
        
        BeanFactory factory=new XmlBeanFactory(new FileSystemResource(filePath));
        GreetingHelloworldImpl greetingSerview=(GreetingHelloworldImpl)factory.getBean("greeting");
        greetingSerview.sayHelloworld();

    }
    
//    public static String getRealPath(String filename){
//        String path="";
//        Class theClass=TestHelloWorld.class;   
//        java.net.URL  u= theClass.getResource(filename);   
//        return u.getPath();
//        
//        
//    }
    
    


}

 

运行结果：

hello world!
this is helloworld from construtor