Spring支持3种依赖注入方式，分别为属性注入、构造器注入和工厂方法注入(很少使用，不推荐)，下面分别对属性注入和构造器注入详细讲解。

1、常量注入

　　属性注入是通过setter方法注入Bean的属性值，属性注入使用<property>元素，使用name属性指定Bean的属性名称，使用value属性或者<value>子节点指定属性值。

beans.xml文件主要内容

Person.java

package com.spring;public class Person {	private String name;	private int age;	private double height;	private double weight;		public Person(String name, int age, double height, double weight) {		super();		this.name = name;		this.age = age;		this.height = height;		this.weight = weight;	}		public Person() {		super();	}			public double getHeight() {		return height;	}	public void setHeight(double height) {		this.height = height;	}	public double getWeight() {		return weight;	}	public void setWeight(double weight) {		this.weight = weight;	}	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public int getAge() {		return age;	}	public void setAge(int age) {		this.age = age;	}	@Override	public String toString() {		return "Person [name=" + name + ", age=" + age + ", height=" + height + ", weight=" + weight + "]";	}				}

 

Main.java

package com.spring;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Main {	public static void main(String[] args) {		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");		Person person = (Person) ctx.getBean("person");		System.out.println(person); 	}}

运行结果截图如下：

以上就是属性注入的例子

2、构造器注入

2.1 按照索引匹配

beans.xml

 

 

结果：

2.2 按类型匹配

beans.xml

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结果：