Spring基于注解的DI-基本注解

红太狼 2022-06-18 05:09 222阅读 0赞

# Spring基于注解的DI-基本注解 #

## 简单的创建一个Java 工程，配置好环境[Spring注解开发基本配置][Spring] ##

![这里写图片描述][SouthEast]

##    Strudent.java ##

package com.hk.spring.di01;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    //与@Component功能相同但是意义不同的注解还有三个
    //1、@Controller （注解在处理器上【SpringMvc】）
    //2、@Repository （注解在Dao实现类上）
    //3、@Service （注解在Service实现类上）
    @Component("myStudent")
    public class Student { 
        @Value("小明")
        private String name;
        @Value("23")
        private int age;
        @Autowired      //域属性的byType自动注入
        private School school;//域属性
        public void setName(String name) {
            this.name = name;
        }
        public void setAge(int age) {
            this.age = age;
        }
    
        public void setSchool(School school) {
            this.school = school;
        }
        @Override
        public String toString() {
            return "Student [name=" + name + ", age=" + age + ", school=" + school
                    + "]";
        }
    
    
    }

### 域属性的byName自动注入      ![这里写图片描述][SouthEast 1]         域属性的byType自动注入的另一种形式 ###

//import javax.annotation.Resource;是Java的标准注入
        @Resource//域属性的byType自动注入
        private School school;//域属性

域属性的byName自动注入的另一种形式

//import javax.annotation.Resource;
        @Resource(name="mySchool")//域属性的byName自动注入
        private School school;//域属性

## School.java ##

package com.hk.spring.di01;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    
    @Component("mySchool")//组件
    public class School { 
        @Value("九江学院")
        private String schloolName;
    
        public void setSchloolName(String schloolName) {
            this.schloolName = schloolName;
        }
    
        @Override
        public String toString() {
            return "School [schloolName=" + schloolName + "]";
        }
    
    }

## applicationContext.xml ##

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
            
             <context:component-scan base-package="com.hk.spring.di01"></context:component-scan>
    </beans>

## Mytest.java ##

package com.hk.spring.di01;
    
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class Mytest {
        @Test
        public void test1(){
            String resource = "com/hk/spring/di01/applicationContext.xml";
            ApplicationContext ac = new ClassPathXmlApplicationContext(resource);
            Student stu = (Student) ac.getBean("myStudent");
            System.out.println(stu);
    
        }
    }

[Spring]: http://blog.csdn.net/leisure_life/article/details/68123797
[SouthEast]: /images/20220618/87cbfd492d9e41cc9adf2b0b54453b69.png
[SouthEast 1]: /images/20220618/631b24e6e2f84ee6a9e61c89117262e1.png