Spring--自动装配

Posted 2020-10-16 Wayfo

XML 配置里的 Bean 自动装配

Spring IOC 容器可以自动装配 Bean. 需要做的仅仅是在 <bean> 的 autowire 属性里指定自动装配的模式

• byType(根据类型自动装配): 若 IOC 容器中有多个与目标 Bean 类型一致的 Bean. 在这种情况下, Spring 将无法判定哪个 Bean 最合适该属性, 所以不能执行自动装配.
• byName(根据名称自动装配): 必须将目标 Bean的名称和setter属性名设置的完全相同.
• constructor(通过构造器自动装配): 当 Bean 中存在多个构造器时, 此种自动装配方式将会很复杂. 不推荐使用

IDEA 会有提示 ：Navigate to the autowired dependencies

<bean id="address" class="yang.mybatis.test.Address"
p:city="BeiJing" p:street="TianAnMen"></bean>

<bean id="car" class="yang.mybatis.test.Car"
p:name="奥迪89" p:brand="奥迪" p:price="300"></bean>

<bean id="person" class="yang.mybatis.test.Person"
p:name="xiaoming" autowire="byName"></bean>

 

package yang.mybatis.test;

import java.util.List;
import java.util.Map;

/**
* Created by yangshijing on 2017/11/29 0029.
*/
public class Person {
private String name;

private Address address;

private Car car;

public Person() {
}

public Person(Address address, Car car, String name) {
this.address = address;
this.car = car;
this.name = name;
}

public Address getAddress() {
return address;
}

public void setAddress(Address address) {
this.address = address;
}

public Car getCar() {
return car;
}

public void setCar1(Car car) {
this.car = car;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public String toString() {
return "Person{" +
"address=" + address +
", name=‘" + name + ‘\‘‘ +
", car=" + car +
‘}‘;
}
}