Spring的实例工厂方法和静态工厂方法实例代码

Spring的实例工厂方法和静态工厂方法都可以用来实例化bean，本文我们就来看看相关实例。

静态工厂方法：直接调用静态方法可以返回Bean的实例

package com.zhu.string.factory;

import java.util.HashMap;
import java.util.Map;

public class StaticCarFactory {
  /**
   * 静态工厂方法：直接调用静态方法可以返回Bean的实例
   *
   */
  private static Map<String ,Car > cars=new HashMap<String , Car>();
  static{
    cars.put("audi",  new Car(3000, "aodi"));
    cars.put("fodo",  new Car(3000, "aodi"));
  }
  //静态工厂方法
  public static Car getCar(String name){
    return cars.get(name);
  }
}

实例工厂方法。即调用工厂本身，再调用工厂的实例方法来返回bean实例

package com.zhu.string.factory;

import java.util.HashMap;
import java.util.Map;

public class InstanceCarFactory {
  /**
   * 实例工厂方法。即调用工厂本身，再调用工厂的实例方法来返回bean实例
   */
  private Map<String ,Car> cars=null;
  public InstanceCarFactory() {
    // TODO Auto-generated constructor stub
    cars=new HashMap<String, Car>();
    cars.put("audi", new Car(1000,"audi"));
    cars.put("dffdas", new Car(2000,"audi"));
  }
  public Car getCar(String brand){
    return cars.get(brand);
  }
}

beans-factory.xml

<span style="font-size:14px;"><?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.xsd">

  <!-- 通过静态方法来配置bean,注意不是配置静态工厂方法实例，而是配置bean实例

-->
  <!--
    class属性：指向静态方法的全类名 factory-method：指向静态方法的名字
    constructor-arg:如果工厂方法需要传入参数，则使用constructor-arg来配

置参数
  -->
  <bean id="car1" factory-method="getCar"
    class="com.zhu.string.factory.StaticCarFactory">
    <constructor-arg value="audi"></constructor-arg>
  </bean>
  <!-- 配置工厂的实例 -->
  <bean id="carFactory" class="com.zhu.string.factory.InstanceCarFactory">
  </bean>
  <bean id="car2" factory-bean="carFactory" factory-method="getCar">
    <constructor-arg value="audi"></constructor-arg>
  </bean>
</beans></span>

Car.java实体类

package com.zhu.string.factory;
public class Car {
    private double price;
    private String brand;
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public String getBrand() {
        return brand;
    }
    public void setBrand(String brand) {
        this.brand = brand;
    }
    @Override
      public String toString() {
        return "Car [brand=" + brand + ", price=" + price + "]";
    }
    public Car(){
        System.out.println("cars....constructor");
    }
    public Car(double price, String brand) {
        super();
        this.price = price;
        this.brand = brand;
    }
}

Main.java

package com.zhu.string.factory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
    /**
   * @param args
   */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ApplicationContext cx=new ClassPathXmlApplicationContext("beans-
factory.xml");
        Car car1=(Car) cx.getBean("car1");
        System.out.println(car1);
        Car car2=(Car) cx.getBean("car2");
        System.out.println(car2);
    }
}

运行结果：

Car [brand=aodi, price=3000.0]
Car [brand=audi, price=1000.0]

总结

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原文链接：http://blog.csdn.net/zhupengqq/article/details/51799320