Spring框架开发IOC两种创建工厂方法详解

public class HelloFactory {
    public static HelloWorld getInstance(){
        return new Hello();
    }
}
HelloWorldFactory.getInstance();
 

public class Hello {
    public HelloWorld createHelloWorld(){
        return new Hello();
    }
}
Hello helloF = new Hello();
hello.createHelloWorld();

package entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Car {
 private long id;
 private String name;
}
 
package factory;
import entity.Car;
import java.util.HashMap;
import java.util.Map;
public class StaticCarFactory {
 private static Map<Long, Car> carMap;
 static{
 carMap = new HashMap<Long, Car>();
 carMap.put(1L,new Car(1L,"宝⻢"));
 carMap.put(2L,new Car(2L,"奔驰"));
 }
 public static Car getCar(long id){
 return carMap.get(id);
 }
}

<!-- 配置静态⼯⼚创建 Car -->
<bean id="car" class="com.southwind.factory.StaticCarFactory" factorymethod="getCar">
 <constructor-arg value="2"></constructor-arg>
</bean>

package factory;
import entity.Car;
import java.util.HashMap;
import java.util.Map;
public class InstanceCarFactory {
 private Map<Long, Car> carMap;
 public InstanceCarFactory(){
 carMap = new HashMap<Long, Car>();
 carMap.put(1L,new Car(1L,"宝⻢"));
 carMap.put(2L,new Car(2L,"奔驰"));
 }
 public Car getCar(long id){
 return carMap.get(id);
 }
}

<!-- 配置实例⼯⼚ bean -->
<bean id="carFactory" class="factory.InstanceCarFactory">
</bean>
<!-- 赔偿实例⼯⼚创建 Car -->
<bean id="car2" factory-bean="carFactory" factory-method="getCar">
 <constructor-arg value="1"></constructor-arg>
</bean>