Spring中四种依赖注入的方式(推荐注解注入)

注解注入(1)

注解注入 (2)

构造函数注入

代码如下(如果不会使用lombok插件的可以直接生成get、set、构造以及toString方法)：
实体类 User.java

@Data
public class User {
    private String username;
    private String height;

    public User(String username, String height) {
        this.username = username;
        this.height = height;
    }

}

测试类UserTest.java

public class UserTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-context.xml");
        User user = (User) context.getBean("user",User.class);
        System.out.println(user);

    }
}

配置文件 spring-context.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

   <bean id="user" class="com.zh.spring.test.entity.User">
       <constructor-arg name="username" value="刘强西"></constructor-arg>
       <constructor-arg name="height" value="175"></constructor-arg>
   </bean>
</beans>

属性注入