FactoryBean的练习

FactoryBean是一个Bean，但是这个bean的特殊之处在于他创建的不是自己，而是别的bean。<br />如果将其注入后可以使用`&+id`的方式取出自己。[https://gitee.com/gao_xi/spring-demo1/tree/factory-bean/](https://gitee.com/gao_xi/spring-demo1/tree/factory-bean/)

• XML配置 ```xml

- FactoryBean对象
```java
public class AuthorFactoryBean implements FactoryBean<Author> {
    @Override
    public Author getObject() throws Exception {
        Author author = new Author();
        author.setAge(10);
        author.setName("高溪");
        return author;
    }
    @Override
    public Class<?> getObjectType() {
        return Author.class;
    }
    @Override
    public boolean isSingleton() {
        return true;
    }
}

• 被FactoryBean创建的对象 ```java public class Author {

  private String name;

  private Integer age;

public void setName(String name) {
    this.name = name;
}
public void setAge(Integer age) {
    this.age = age;
}
@Override
public String toString() {
    return "Author{" +
        "name='" + name + '\'' +
        ", age=" + age +
        '}';
}

}

- 启动类
```java
    /**
     * 各种类型的注入方式
     */
    @Test
    public void testAllType() {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("config.xml");
        Author bean = applicationContext.getBean(Author.class);
        System.out.println(bean);
        //通过name获取的是Author
        Object authorFactoryBean = applicationContext.getBean("authorFactoryBean");
        System.out.println(authorFactoryBean);
        //获取自身
        AuthorFactoryBean self = (AuthorFactoryBean) applicationContext.getBean("&authorFactoryBean");
        System.out.println(self.isSingleton());
    }