StudentSystem 학생 관리 시스템V1(3)

비즈니스 클래스 설계

질문: 왜 Dao 클래스를 직접 사용하지 않고 서비스 레이어를 위에 봉인해야 합니까?

대답: 책임 분리의 원칙을 바탕으로 Dao층은 데이터베이스에 대한 조작에 전념해야 한다. 서비스 층에서 우리는 CRUD가 아닌 방법을 추가하여 자신이 추출한 서비스(업무 처리)를 더욱 잘 완성할 수 있다.

[com.ray.service] 패키지 아래에 [Student Service] 인터페이스를 만들려면 다음과 같이 하십시오.

/**
 * @author Ray
 * @date 2018/5/27 0027
 * Service            CRUD                  service   
 */
public interface StudentService {

    /**
     *     Student    
     * @return
     */
    int getTotal();

    /**
     *       
     * @param student
     */
    void addStudent(Student student);

    /**
     *       
     * @param id
     */
    void deleteStudent(int id);

    /**
     *       
     * @param student
     */
    void updateStudent(Student student);

    /**
     *       
     * @param id
     * @return
     */
    Student getStudent(int id);

    /**
     *      start       count    
     * @param start
     * @param count
     * @return
     */
    List list(int start, int count);
}

[com.ray.service.impl] 패키지에서 [StudentServiceImpl]을 만듭니다.

/**
 * @author Ray
 * @date 2018/5/27 0027
 * StudentService     
 */
@Service
public class StudentServiceImpl implements StudentService {

    @Autowired
    StudentDao studentDao;

    public int getTotal() {
        return studentDao.getTotal();
    }

    public void addStudent(Student student) {
        studentDao.addStudent(student);
    }

    public void deleteStudent(int id) {
        studentDao.deleteStudent(id);
    }

    public void updateStudent(Student student) {
        studentDao.updateStudent(student);
    }

    public Student getStudent(int id) {
        return studentDao.getStudent(id);
    }

    public List list(int start, int count) {
        return studentDao.list(start, count);
    }
}

기능 개발
[com.ray.controller] 패키지 아래에 [StudentController] 컨트롤러를 만듭니다.

/**
 * @author Ray
 * @date 2018/5/27 0027
 * Student    
 */
@Controller
public class StudentController {

    @Autowired
    private StudentService studentService;

    /**
     *       
     */
    @RequestMapping("/addStudentView")
    public ModelAndView addStudentView(){
        ModelAndView modelAndView = new ModelAndView("addStudentView");
        return modelAndView;
    }

    /**
     *       
     */
    @RequestMapping("/addStudent")
    public String addStudent(HttpServletRequest request, HttpServletResponse response){

        Student student = new Student();

        int studentId = Integer.parseInt(request.getParameter("student_id"));
        String name = request.getParameter("name");
        int age = Integer.parseInt(request.getParameter("age"));
        String sex = request.getParameter("sex");
        Date birthday = null;
        // String      yyyy-MM-dd        java.util.Date  
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        try{
            birthday = simpleDateFormat.parse(request.getParameter("birthday"));
        }catch (Exception e){
            e.printStackTrace();
        }

        student.setStudent_id(studentId);
        student.setName(name);
        student.setAge(age);
        student.setSex(sex);
        student.setBirthday(birthday);

        studentService.addStudent(student);

        return "redirect:listStudent"; //    
    }

    /**
     *         
     */
    @RequestMapping("/listStudent")
    public String listStudent(HttpServletRequest request, HttpServletResponse response){

        //       
        int start = 0;
        int count = 10;

        try{
            start = Integer.parseInt(request.getParameter("page.start"));
            count = Integer.parseInt(request.getParameter("page.count"));
        }catch (Exception e){
            e.printStackTrace();
        }

        Page page = new Page(start, count);

        List students = studentService.list(page.getStart(), page.getCount());
        int total = studentService.getTotal();
        page.setTotal(total);

        request.setAttribute("students", students);
        request.setAttribute("page", page);

        return "listStudent";
    }

    /**
     *         
     */
    @RequestMapping("/editStudent")
    public ModelAndView editStudent(int id){
        ModelAndView modelAndView = new ModelAndView("editStudent");
        Student student = studentService.getStudent(id);
        modelAndView.addObject("student",student);
        return modelAndView;
    }

    /**
     *          
     */
    @RequestMapping("/updateStudent")
    public String updateStudent(HttpServletRequest request, HttpServletResponse response){
        Student student = new Student();

        int id = Integer.parseInt(request.getParameter("id"));
        int student_id = Integer.parseInt(request.getParameter("student_id"));
        String name = request.getParameter("name");
        int age = Integer.parseInt(request.getParameter("age"));
        String sex = request.getParameter("sex");

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date birthday = null;
        try{
            birthday = simpleDateFormat.parse(request.getParameter("birthday"));
        }catch (Exception e){
            e.printStackTrace();
        }

        student.setId(id);
        student.setStudent_id(student_id);
        student.setName(name);
        student.setAge(age);
        student.setSex(sex);
        student.setBirthday(birthday);

        studentService.updateStudent(student);
        return "redirect:listStudent";
    }

    /**
     *          
     */
    @RequestMapping("/deleteStudent")
    public String deleteStudent(int id){
        studentService.deleteStudent(id);
        return "redirect:listStudent";
    }
}

페이지 나누기 기능
Packge [util] 패키지 아래에 Page 도구 클래스를 먼저 만듭니다.

package com.ray.util;

/**
 * @author Ray
 * @date 2018/5/27 0027
 *     
 */
public class Page {

    int start; //     
    int count; //       
    int total; //       

    public Page(int start, int count){
        super();
        this.start = start;
        this.count = count;
    }

    public boolean isHasPreviouse(){
        if(start == 0){
            return false;
        }
        return true;
    }

    public boolean isHasNext(){
        if(start == getLast()){
            return false;
        }
        return true;
    }

    public int getTotalPage(){
        int totalPage;

        //    50,    5   ,    10 
        if(0 == total % count){
            totalPage = total / count;
        }else{
            //    51,   5   ,    11 
            totalPage = total / count + 1;
        }

        if(0 == totalPage){
            totalPage = 1;
        }

        return totalPage;
    }

    public int getLast(){
        int last;
        //     50,   5   ,           40
        if(0 == total % count){
            last = total - count;
        }else{
            //     51,    5   ,           50
            last = total - total % count;
        }

        last = last < 0 ? 0:last;
        return last;
    }

    public int getStart() {
        return start;
    }

    public void setStart(int start) {
        this.start = start;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }
}