MacWire 为给定的类生成新的实例创建代码,在 Scala 宏的帮助下通过在构造函数参数的封闭类型中使用值实现。
MacWire 可以帮助实现依赖注入模式,不必须手工编写代码。
示例代码:
class DatabaseAccess() class SecurityFilter() class UserFinder(databaseAccess: DatabaseAccess, securityFilter: SecurityFilter) class UserStatusReader(userFinder: UserFinder) trait UserModule { import com.softwaremill.macwire.MacwireMacros._ lazy val theDatabaseAccess = wire[DatabaseAccess] lazy val theSecurityFilter = wire[SecurityFilter] lazy val theUserFinder = wire[UserFinder] lazy val theUserStatusReader = wire[UserStatusReader] }
生成的代码:
trait UserModule { lazy val theDatabaseAccess = new DatabaseAccess() lazy val theSecurityFilter = new SecurityFilter() lazy val theUserFinder = new UserFinder(theDatabaseAccess, theSecurityFilter) lazy val theUserStatusReader = new UserStatusReader(theUserFinder) }