[TOC] # spring4 的新特性 --- 泛型注入 廢話不多說, 直接上代碼 1. 寫一個實體類 ~~~ package generic; import java.io.Serializable; public class User implements Serializable{ private static final long serialVersionUID = 1L; private String name; private int age; //setter和getter } ~~~ 2. 公共 DAO:BaseDao(crud 都寫在這里) ~~~ package generic; public abstract class BaseDao<T> { public void save(T t){ System.out.println("....."); } public void delete(){ System.out.println("...."); } } ~~~ 3. DAO 的具體實現: UserDa 繼承 BaseDao ~~~ package generic; import org.springframework.stereotype.Repository; @Repository("userDao") public class UserDao extends BaseDao<User>{ } ~~~ 4. 創建基類service ~~~ package generic; import org.springframework.beans.factory.annotation.Autowired; public abstract class BaseService<T> { @Autowired private BaseDao<T> baseDao; public void save(T t){ baseDao.save(t); } } ~~~ 5. 創建userService ~~~ package generic; import org.springframework.stereotype.Service; @Service("userService") public class UserService extends BaseService<User>{ } ~~~ 大家可以看到現在的代碼非常簡潔, 在步驟新四中, 注入的時候 spring 會去自動去找 `BaseDao<User>`的子類實現并注入