Question

这是我在Grails中已经做过的非常简化的例子：

// this can be a service or normal class
public abstract class Person {
    public final String introduceSelf() {
        return "Hi, I'm " + getFullName()
    }

    protected abstract String getFullName()
}

// Service
class AlexService extends Person {
    protected String getFullName() {
        return "Alex Goodman"
    }
}

// Service
class BobService extends Person {
    protected String getFullName() {
        return "Bob Goodman"
    }
}

// Service
class CarlService extends Person {
    protected String getFullName() {
        return "Carl Goodman"
    }
}

// Controller
class IntroduceController {
    def alex
    def bob
    def carl

    def index() {
        if(params.person == "a")
            render alex.introduceSelf()
        if(params.person == "b")
            render bob.introduceSelf()
        if(params.person == "c")
            render carl.introduceSelf()
    }
}

我正在寻找更多面向对象的方式，例如：

// Controller
class IntroduceController {
    def person

    def index() {
        // inject a proper person in a more object oriented way

        render person.introduceSelf()
    }
}

您能否建议如何以更加面向对象/动态的方式实现这一目标？

Answer 1

您可以在person文件中编写grails-app/conf/spring/resources.groovy bean定义。例如：

beans = {
    person(BobService)
}

有关详情，请查看：http://grails.org/doc/latest/guide/spring.html#springdslAdditional

Answer 2

class IntroduceController {

  def grailsApplication

  def index() {
    def person = grailsApplication.mainContext.getBean( params.person )
    person.doSomething()
  }

}

您必须确保您的服务名称与params.person值相对应，params.person = 'bob'可以使用，params.person = 'b'不会

依赖注入：有条件的

2 个答案: