1、通过bean标签的autowire属性可以实现bean属性的自动装配。
创建一个新的Spring配置文件beans-autowire.xml，这里我们配置了3个bean，Address、Car、People，其中People自动装配了另外两个bean，使用的是bean标签的autowire属性，这个例子里如果将car改为car2打印出来的Person bean 的Car属性为null，即byName根据bean的setter风格进行自动装配有就装没有就不装。而使用byType的话如果配置有两个类型相同的bean就会报错。
<?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:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd"> <bean id="address" class="com.broadtext.beans.autowire.Address">
<property name="city" value="Hefei"></property>
<property name="street" value="Feixilu"></property>
</bean> <bean id="car" class="com.broadtext.beans.autowire.Car">
<property name="brand" value="Audi"></property>
<property name="price" value="300000"></property>
</bean> <!-- 可以使用autowire属性指定自动装配的方式，
byName根据bean的setter风格进行自动装配有就装没有就不装，
byType根据bean的类型和bean的属性的类型进行自动装配，一个以上类型匹配则抛异常
-->
<bean id="person" class="com.broadtext.beans.autowire.Person" autowire="byName" p:name="hj"></bean> </beans>
2、Address.java、Car.java、People.java、Main.java
Address.java
package com.broadtext.beans.autowire;
public class Address {
private String city;
private String street;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
@Override
public String toString() {
return "Address [city=" + city + ", street=" + street + "]";
}
}
Car.java
package com.broadtext.beans.autowire;
public class Car {
private String brand;
private double price;
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
@Override
public String toString() {
return "Car [brand=" + brand + ", price=" + price + "]";
}
public Car() {
System.out.println("car`s construstor");
}
}
People.java
package com.broadtext.beans.autowire;
public class Person {
private String name;
private Address address;
private Car car;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public Car getCar() {
return car;
}
public void setCar(Car car) {
this.car = car;
}
@Override
public String toString() {
return "Person [name=" + name + ", address=" + address + ", car=" + car + "]";
}
}
Main.java
package com.broadtext.beans.autowire; import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext; public class Main { /**
* <p>Description: 测试bean的自动装配</p>
*/
public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-autowire.xml");
Person person = (Person) ctx.getBean("person");
System.out.println(person);
} }