Spring框架依赖注入方法示例

在阅读这篇文章之前，大家可以先参阅《理解Spring中的依赖注入和控制反转》一文，了解下依赖注入和控制反转的相关内容。

三种依赖注入的方式

属性注入，通过setter方法注入bean的属性值或依赖的对象 构造注入 工厂方法注入（很少使用）
例子

这里我们使用了spring-4.3.2，maven配置文件

 org.springframework
 spring-core
 ${org.springframework-version}
 
  
   commons-logging
   commons-logging
  
 


 org.springframework
 spring-beans
 ${org.springframework-version}


 org.springframework
 spring-aop
 ${org.springframework-version}


 org.springframework
 spring-context
 ${org.springframework-version}


 commons-logging
 commons-logging
 1.2



 junit
 junit
 3.8.1
 test

applicationContext.xml配置文件

 
 
 
  
 
 
 
 
  
  
 
 
  
  
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    jdbc:mysql://test
    com.mysql.jdbc.Driver
   
  
 
 
 
 
  
  
 
 
 
  
  
  
 
 
 
 

1. 下面是简单的属性注入、构造注入的测试类

Car.java

package com.spring.test;
public class Car {
	private String name;
	private int maxSpeed;
	private double price;
	public Car() {
	}
	public Car(String name, double price) {
		this.name = name;
		this.price = price;
	}
	public Car(String name, int maxSpeed) {
		this.name = name;
		this.maxSpeed = maxSpeed;
	}
	public Car(String name, double price, int maxSpeed) {
		this.name = name;
		this.price = price;
		this.maxSpeed = maxSpeed;
	}
	public void setPrice(double price) {
		this.price = price;
	}
	@Override
	 public String toString() {
		return "Car [name:" + name + ", price:" + price + ", maxSpeed:" + maxSpeed + "]";
	}
}

HelloWorld.java

package com.spring.test;
public class HelloWorld {
	private String name;
	public HelloWorld() {
		System.out.println("HelloWorld constructor...");
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		System.out.println("setName:" + name);
		this.name = name;
	}
	@Override
	 public String toString() {
		return "hello," + name;
	}
}

Person.java

package com.spring.test;
public class Person {
	private String name;
	private int age;
	private Car car;
	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;
	}
	public Car getCar() {
		return car;
	}
	public void setCar(Car car) {
		this.car = car;
	}
	@Override
	 public String toString() {
		return "Person: [name=" + name + ", age=" + age + ", car=" + car + "]";
	}
}

Main.java

package com.spring.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
	public static void main(String[] args) {
		HelloWorld hello = new HelloWorld();
		hello.setName("barry");
		System.out.println("print:"+ hello + "n");
		// 装入 Spring 配置文件
		
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//HelloWorld hello1 = (HelloWorld) context.getBean("helloWorld"); // 通过id获取bean对象
		HelloWorld hello1 = context.getBean(HelloWorld.class);
		// 通过类型获取bean对象（要求在IOC容器里该类型的对象只能有一个）
		System.out.println(hello1);
	}
	@Test
	 public void testContructor() {
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		Car car = (Car) context.getBean("car");
		// 通过类型获取bean对象（要求在IOC容器里该类型的对象只能有一个）
		Car car1 = (Car) context.getBean("car1");
		System.out.println(car);
		System.out.println(car1);
		Person person = (Person) context.getBean("person");
		System.out.println(person);
	}
}

2. 下面是集合的测试类
NewPerson.java

package com.spring.test.collections;
import java.util.Map;
import com.spring.test.Car;
public class NewPerson {
	private String name;
	private int age;
	private Map cars;
	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;
	}
	public Map getCars() {
		return cars;
	}
	public void setCars(Map cars) {
		this.cars = cars;
	}
	@Override
	 public String toString() {
		return "Person: [name=" + name + ", age=" + age + ", cars=" + cars + "]";
	}
}

Person.java

package com.spring.test.collections;
import java.util.List;
import com.spring.test.Car;
public class Person {
	private String name;
	private int age;
	private List cars;
	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;
	}
	public List getCars() {
		return cars;
	}
	public void setCars(List cars) {
		this.cars = cars;
	}
	@Override
	 public String toString() {
		return "Person: [name=" + name + ", age=" + age + ", cars=" + cars + "]";
	}
}

DataSource.java

package com.spring.test.collections;
import java.util.Properties;
public class DataSource {
	private Properties properties;
	public Properties getProperties() {
		return properties;
	}
	public void setProperties(Properties properties) {
		this.properties = properties;
	}
	@Override
	 public String toString() {
		return "DataSource: [properties:" + properties + "]";
	}
}

Main.java

package com.spring.test.collections;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
	@Test
	 public void testCollections() {
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		Person person = (Person) context.getBean("person3");
		System.out.println(person);
		NewPerson newPerson = (NewPerson) context.getBean("newPerson");
		System.out.println(newPerson);
		DataSource dataSource = (DataSource) context.getBean("dataSource");
		System.out.println(dataSource);
		Person person4 = (Person) context.getBean("person4");
		System.out.println(person4);
		Person person5 = (Person) context.getBean("person5");
		System.out.println(person5);
	}
}

总结

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