UserDao与UserDaoImpl:
public interface UserDao {
public void save();
}
public class UserDaoImpl implements UserDao {
public void save() {
System.out.println("保存用户...");
}
}
UserService接口及其实现类UserServiceImpl:
public interface UserService {
public void addUser();
}
public class UserServiceImpl implements UserService {
private UserDao userDao;
private String username;
//这里的成员变量不需要setter方法。这是与setter注入不同的地方
public UserServiceImpl(UserDao userDao, String username) {
this.userDao = userDao;
this.username = username;
}
public void addUser() {
System.out.println(username);
userDao.save();
}
}
配置:
<bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <!-- index表示的是构造方法中的第几个参数。从0开始。 --> <bean id="userService" class="cn.framelife.spring.service.impl.UserServiceImpl"> <constructor-arg index="0" ref="userDao"></constructor-arg> <constructor-arg index="1" value="zhangsan"></constructor-arg> </bean>