C02_D10_Annotation_Autowired_exercise

//entity    
/**
 * *学生实体类，用于存储学生所有信息
 * 
 * @author 22-426
 */
public class Student implements Serializable {

    private String srollno;

    private String sname;

    private String sgender;

    private String sbatch;

    private String spassword;

    public Student() {
    }

    public Student(String srollno, String sname, String spassword, String sgender, String sbatch) {
        this.srollno = srollno;
        this.sname = sname;
        this.sgender = sgender;
        this.sbatch = sbatch;
        this.spassword = spassword;
    }

    public String getSrollno() {
        return srollno;
    }

    public void setSrollno(String srollno) {
        this.srollno = srollno;
    }

    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    public String getSgender() {
        return sgender;
    }

    public void setSgender(String sgender) {
        this.sgender = sgender;
    }

    public String getSbatch() {
        return sbatch;
    }

    public void setSbatch(String sbatch) {
        this.sbatch = sbatch;
    }

    public String getSpassword() {
        return spassword;
    }

    public void setSpassword(String spassword) {
        this.spassword = spassword;
    }

    @Override
    public String toString() {
        return srollno + "\t" + sname + "\t\t" + spassword + "\t\t" + sgender + "\t" + sbatch;
    }
}

//dao&daoImpl
public interface StudentDao {

    Student getOneStudent(String id);
}
//@Component注解可以将一个类注册为spring管理的bean
//但是spring专门为Dao类提供了一个相同功能的注解@Repository
@Repository
public class StudentDaoImpl implements StudentDao {

    @Override
    public Student getOneStudent(String id) {
        System.out.println("......................调用了StudentDaoImpl的getOneStudent()方法......................");
        return new Student("2018208888", "小明", "123456", "M", "18软件J01");
    }
}

//service&serviceImpl
public interface StudentService {

    void login(String id, String pwd);

}
//@Component注解可以将一个类注册为spring管理的bean
//但是spring专门为Service类提供了一个相同功能的注解@Service
@Service
public class StudentServiceImpl implements StudentService {

    //自动装配的前提是两个bean（依赖的bean和被依赖的bean）都归spring容器管理
    StudentDao studentDao;

    //如果将@Autowired注解放在构造函数前，则spring容器调用构造函数实现自动装配
    @Autowired
    public StudentServiceImpl(StudentDao studentDao) {
        this.studentDao = studentDao;
    }

    @Override
    public void login(String id, String pwd) {
        System.out.println("......................调用了StudentServiceImpl的login()方法.................................");
        Student s = studentDao.getOneStudent(id);
        if (null != s && pwd.equals(s.getSpassword()))
            System.out.println("学号和密码正确，登录成功~~~");
        else
            System.out.println("学号或密码错误，登录失败！！！");
    }
}

//config-beans.xml
    <!-- 开启包扫描，给对应的类加注解，注册为spring管理的bean -->
    <!-- 并且使用@Autowired注解将StudentDao对象注入StudentServiceImpl中 -->

    <!-- 扫描包可以指定多个包名，逗号隔开多个包名即可 -->
    <context:component-scan base-package="com.qdu.service,com.qdu.dao">
    </context:component-scan>

//main
public static void main(String[] args) {

        ApplicationContext ctx=
                new ClassPathXmlApplicationContext("config/beans.xml");
        StudentService service=ctx.getBean(StudentService.class);
        service.login("2018208888","123456");

    }