问题描述：
一个非常简单的spring项目，用静态工厂方法配置bean实例。项目的目录结构如下：
代码如下：
Car.java
1 package com.tt.spring.beans.factory;
2
3 public class Car {
4
5 private String brand;
6 private double price;
7
8 public String getBrand() {
9 return brand;
10 }
11 public void setBrand(String brand) {
12 this.brand = brand;
13 }
14 public double getPrice() {
15 return price;
16 }
17 public void setPrice(double price) {
18 this.price = price;
19 }
20
21 public Car(){
22 System.out.println("Car's Constructor...");
23 }
24
25
26
27 public Car(String brand, double price) {
28 super();
29 this.brand = brand;
30 this.price = price;
31 }
32
33 @Override
34 public String toString() {
35 return "Car [brand=" + brand + ", price=" + price + "]";
36 }
37
38
39 }
StaticCarFactory.java
1 package com.tt.spring.beans.factory;
2
3 import java.util.HashMap;
4 import java.util.Map;
5
6 /**
7 * 静态工厂方法：直接调用某一个类的静态方法就可以返回Bean的实例
8 */
9 public class StaticCarFactory {
10
11
12 private static Map<String,Car> cars = new HashMap<String, Car>();
13
14 static{
15 cars.put("Audi",new Car("Audi",300000));
16 cars.put("Ford", new Car("Ford",40000));
17 }
18
19 //静态工厂方法
20 public static Car getCar(String name){
21 return cars.get(name);
22
23 }
24
25 }
beans-factory.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xmlns:p="http://www.springframework.org/schema/p" 6 xmlns:util="http://www.springframework.org/schema/util" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd 9 http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd"> 10 11 <!-- 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 --> 12 <bean id="car1" 13 class="com.tt.spring.beans.factory.StaticCarFactory" 14 factory-method="getCar"> 15 <constructor-arg value="Audi"></constructor-arg> 16 </bean> 17 18 19 </beans>
Main.java:
1 package com.tt.spring.beans.factory;
2
3 import org.springframework.context.ApplicationContext;
4 import org.springframework.context.support.ClassPathXmlApplicationContext;
5
6 public class Main {
7
8 public static void main(String[] args){
9
10 ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-factory.xml");
11
12 Car car1 = (Car) ctx.getBean("car1");
13 System.out.println(car1);
14 }
15 }
运行Main.java程序，控制台报错如下：
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
Type mismatch: cannot convert from Object to Car
at com.tt.spring.beans.factory.Main.main(Main.java:12)
原因分析：
第一, 需要装 jre1.5.0及以上的版本
第二, 在eclipse的'Window' 'Preference' 'Java'里,
'Install JREs'里设置你装的jre
第三,在eclipse的'Window' 'Preference' 'Java'里,
'Compiler'里设'Compiler compliance level'为5.0以上
（关键是第三步, 兼容级别）
问题解决：
由于我安装的jdk版本是1.8.0的，所以问题应该出在Compiler compliance level上。
进入Window->Preference->Java->Compiler,发现Compiler compliance level=1.5
将Compiler compliance level改成1.8：
再运行Main.java代码，运行正常，控制台显示如下信息：
来源：https://www.cnblogs.com/TTTTT/p/6404683.html