外键和日期时间处理
一、外键
上一节我们写了部门表，本节我们以员工表为例：
1、员工实体【Employee】
package _15MVC.d01.cn.com.entity;
/**员工实体
* @author LX
* @create 2023-12-24 20:24
*/
public class Employee {
private String emp_no;
private String emp_name;
private String emp_sex;
private int emp_age;
//private int dep_no;//不需要外键字段，外键封装在主表对象部门中
private Departement departement;//为外键准备
public Employee() {
}
public Employee(String emp_no, String emp_name, String emp_sex, int emp_age, Departement departement) {
this.emp_no = emp_no;
this.emp_name = emp_name;
this.emp_sex = emp_sex;
this.emp_age = emp_age;
this.departement = departement;
}
public Departement getDepartement() {
return departement;
}
public void setDepartement(Departement departement) {
this.departement = departement;
}
public String getEmp_no() {
return emp_no;
}
public void setEmp_no(String emp_no) {
this.emp_no = emp_no;
}
public String getEmp_name() {
return emp_name;
}
public void setEmp_name(String emp_name) {
this.emp_name = emp_name;
}
public String getEmp_sex() {
return emp_sex;
}
public void setEmp_sex(String emp_sex) {
this.emp_sex = emp_sex;
}
public int getEmp_age() {
return emp_age;
}
public void setEmp_age(int emp_age) {
this.emp_age = emp_age;
}
}
2、员工dao层接口
package _15MVC.d01.cn.com.dao;
import _15MVC.d01.cn.com.entity.Employee;
import java.util.List;
/**员工表dao
* @author LX
* @create 2023-12-27 17:04
*/
public interface EmployeeDao {
public int insert(Employee employee);
public int delete(Employee employee);
public int update(Employee employee);
public List<Employee> selectAll();
public Employee selectById(Employee employee);
}
3、员工dao层接口的实现类
package _15MVC.d01.cn.com.dao.impl;
import _15MVC.d01.cn.com.dao.BaseDao;
import _15MVC.d01.cn.com.dao.EmployeeDao;
import _15MVC.d01.cn.com.entity.Departement;
import _15MVC.d01.cn.com.entity.Employee;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
/**
* @author LX
* @create 2023-12-27 17:07
*/
public class EmployeeDaoImpl extends BaseDao implements EmployeeDao {
//增加员工
public int insert(Employee employee) {
int i=-1;
openCon();
String sql="insert into employee(emp_no,emp_name,emp_sex,emp_age,dep_no) values(?,?,?,?,?)";
try {
pst=con.prepareStatement(sql);
pst.setString(1,employee.getEmp_no());
pst.setString(2,employee.getEmp_name());
pst.setString(3,employee.getEmp_sex());
pst.setInt(4,employee.getEmp_age());
//外键占位符赋值
pst.setInt(5,employee.getDepartement().getDep_no());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll();
}
return i;
}
//删除员工
public int delete(Employee employee) {
int i=-1;
openCon();
String sql="delete from employee where emp_no=?";
try {
pst=con.prepareStatement(sql);
pst.setString(1,employee.getEmp_no());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll();
}
return i;
}
//修改员工
public int update(Employee employee) {
int i=-1;
openCon();
String sql="update employee set emp_name=? where emp_no=?";
try {
pst=con.prepareStatement(sql);
pst.setString(1,employee.getEmp_name());
pst.setString(2,employee.getEmp_no());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll();
}
return i;
}
//查询所有员工
public List<Employee> selectAll() {
List<Employee> list=null;
openCon();
String sql="select * from employee";
try {
pst=con.prepareStatement(sql);
ResultSet rs =pst.executeQuery();
list=new ArrayList<Employee>();
while (rs.next()){
Employee employee=new Employee();
employee.setEmp_no(rs.getString("emp_no"));
employee.setEmp_name(rs.getString("emp_name"));
employee.setEmp_sex(rs.getString("emp_sex"));
employee.setEmp_age(rs.getInt("emp_age"));
//外键赋值，先存外键值到部门对象，在把部门对象存入员工对象
Departement d=new Departement();
d.setDep_no(rs.getInt("dep_no"));
employee.setDepartement(d);
list.add(employee);
}
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll();
}
return list;
}
//根据id查询员工信息
public Employee selectById(Employee employee) {
Employee e=new Employee();
openCon();
String sql="select * from employee where emp_no=?";
try {
pst=con.prepareStatement(sql);
pst.setString(1,employee.getEmp_no());
//查询返回结果集
rs= pst.executeQuery();
while(rs.next()){
//从结果集中把数据取出放到对象里
e.setEmp_no(rs.getString("emp_no"));
e.setEmp_name(rs.getString("emp_name"));
e.setEmp_sex(rs.getString("emp_sex"));
e.setEmp_age(rs.getInt("emp_age"));
//先存外键值到部门对象，在把部门对象存入员工对象
Departement d=new Departement();
d.setDep_no(rs.getInt("dep_no"));
e.setDepartement(d);
}
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll();
}
return e;
}
}
4、员工service层接口和实现层
package _15MVC.d01.cn.com.service;
import _15MVC.d01.cn.com.entity.Employee;
import java.util.List;
/**
* @author LX
* @create 2023-12-27 17:38
*/
public interface EmployeeService {
public boolean add(Employee employee);
public boolean remove(Employee employee);
public boolean modify(Employee employee);
public List<Employee> findAll();
public Employee findById(Employee employee);
}
package _15MVC.d01.cn.com.service.impl;
import _15MVC.d01.cn.com.dao.EmployeeDao;
import _15MVC.d01.cn.com.dao.impl.EmployeeDaoImpl;
import _15MVC.d01.cn.com.entity.Employee;
import _15MVC.d01.cn.com.service.EmployeeService;
import java.util.List;
/**
* @author LX
* @create 2023-12-27 17:40
*/
public class EmployeeServiceImpl implements EmployeeService {
//上调下，私有化
private EmployeeDao employeeDao=new EmployeeDaoImpl();
public boolean add(Employee employee) {
return employeeDao.insert(employee)>0;
}
public boolean remove(Employee employee) {
return employeeDao.delete(employee)>0;
}
public boolean modify(Employee employee) {
return employeeDao.update(employee)>0;
}
public List<Employee> findAll() {
return employeeDao.selectAll();
}
public Employee findById(Employee employee) {
return employeeDao.selectById(employee);
}
}
5、测试类
package _15MVC.d01.cn.com.test;
import _15MVC.d01.cn.com.entity.Departement;
import _15MVC.d01.cn.com.entity.Employee;
import _15MVC.d01.cn.com.service.DepartmentService;
import _15MVC.d01.cn.com.service.EmployeeService;
import _15MVC.d01.cn.com.service.impl.DepartmentServiceImpl;
import _15MVC.d01.cn.com.service.impl.EmployeeServiceImpl;
import java.util.List;
import java.util.Scanner;
/**
* @author LX
* @create 2023-12-24 22:42
*/
public class Test {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
int var=0;//菜单判断，执行什么操作
boolean flag=false;//接收结果
DepartmentService departmentService=new DepartmentServiceImpl();
// Departement departement=null;//在使用时需要先new，否则会报空指针异常
Departement departement=new Departement();
EmployeeService employeeService=new EmployeeServiceImpl();
Employee employee=new Employee();
do {
System.out.println("----------*欢迎使用员工管理系统*----------");
System.out.println("----------*增加部门信息请按11*增加员工信息请按12*----------");
System.out.println("----------*删除部门信息请按21*删除员工信息请按22*----------");
System.out.println("----------*修改部门信息请按31*修改员工信息请按32*----------");
System.out.println("----------*查询所有部门信息请按41*查询所有员工信息请按42*----------");
System.out.println("----------*通过部门编号查询部门请按51*通过员工编号查询员工请按52*----------");
System.out.println("----------*结束使用请按0*----------");
System.out.println("----------*请输入你的选择：*----------");
var=input.nextInt();
switch (var){
case 11:
System.out.println("----------请输入部门编号：----------");
int depno=input.nextInt();
System.out.println("----------请输入部门名称：----------");
String depname=input.next();
System.out.println("----------请输入部门位置：----------");
String deploc=input.next();
departement.setDep_no(depno);
departement.setDep_name(depname);
departement.setDep_loc(deploc);
flag=departmentService.add(departement);
if (flag){
System.out.println("添加部门信息成功！");
}else{
System.out.println("添加部门信息失败！");
}
break;
case 21:
System.out.println("----------请输入部门编号：----------");
depno=input.nextInt();
departement.setDep_no(depno);
flag=departmentService.remove(departement);
if (flag){
System.out.println("删除成功！");
}else {
System.out.println("删除失败！");
}
break;
case 31:
System.out.println("----------请输入要修改的部门编号：----------");
depno=input.nextInt();
System.out.println("----------请输入新的部门名称：----------");
depname=input.next();
flag=departmentService.modify(departement);
if (flag) {
System.out.println("修改成功！");
}else {
System.out.println("修改失败！");
}
break;
case 41:
System.out.println("部门编号\t部门名称\t部门位置");
List<Departement> list=departmentService.findAll();
for (Departement d:list) {
System.out.println(d.getDep_no()+"\t\t"+d.getDep_name()+"\t"+d.getDep_loc());
}
break;
case 51:
System.out.println("----------请输入要查询的部门编号：----------");
depno=input.nextInt();
departement.setDep_no(depno);
departement=departmentService.findById(departement);
System.out.println("部门编号\t部门名称\t部门位置");
System.out.println(departement.getDep_no()+"\t"+departement.getDep_name()+"\t"+departement.getDep_loc());
break;
case 12:
System.out.println("----------请输入员工编号：----------");
String empno=input.next();
System.out.println("----------请输入员工姓名：----------");
String empname=input.next();
System.out.println("----------请输入员工性别：----------");
String empsex=input.next();
System.out.println("----------请输入员工年龄：----------");
int empage=input.nextInt();
System.out.println("----------请输入部门编号：----------");
depno=input.nextInt();
departement.setDep_no(depno);//先把部门编号存到部门对象
employee.setEmp_no(empno);
employee.setEmp_name(empname);
employee.setEmp_sex(empsex);
employee.setEmp_age(empage);
employee.setDepartement(departement);//在把部门对象存到员工对象
flag=employeeService.add(employee);
if (flag){
System.out.println("添加员工信息成功！");
}else{
System.out.println("添加员工信息失败！");
}
break;
case 22:
System.out.println("----------请输入员工编号：----------");
empno=input.next();
employee.setEmp_no(empno);
flag=employeeService.remove(employee);
if (flag){
System.out.println("删除员工成功！");
}else {
System.out.println("删除员工失败！");
}
break;
case 32:
System.out.println("----------请输入要修改的员工编号：----------");
empno=input.next();
System.out.println("----------请输入新的员工姓名：----------");
empname=input.next();
employee.setEmp_no(empno);
employee.setEmp_name(empname);
flag=employeeService.modify(employee);
if (flag) {
System.out.println("修改员工姓名成功！");
}else {
System.out.println("修改员工姓名失败！");
}
break;
case 42:
System.out.println("员工编号\t\t员工姓名\t\t员工性别\t\t员工年龄\t\t所属部门编号");
List<Employee> list1=employeeService.findAll();
for (Employee e:list1) {
System.out.println(e.getEmp_no()+"\t"+e.getEmp_name()+"\t"+e.getEmp_sex()+"\t"+e.getEmp_age()+"\t"+e.getDepartement().getDep_no());
}
break;
case 52:
System.out.println("----------请输入要查询的员工编号：----------");
empno=input.next();
employee.setEmp_no(empno);
employee=employeeService.findById(employee);
System.out.println("员工编号\t员工姓名\t员工性别\t员工年龄\t所属部门编号");
System.out.println(employee.getEmp_no()+"\t"+employee.getEmp_name()+"\t"+employee.getEmp_sex()+"\t"+employee.getEmp_age()+"\t"+employee.getDepartement().getDep_no());
break;
case 0:
System.out.println("操作结束，欢迎下次光临，再见！！！");
break;
default:
System.out.println("输入错误，请重新选择");
break;
}
} while (var!=0);
/*System.out.println("-----------增加-----------");
departement=new Departement(7,"开发部","222");
if (departmentService.add(departement)) {
System.out.println("添加成功！");
}else {
System.out.println("添加失败！");
}
System.out.println("-----------删除-----------");
departement=new Departement(7,"开发部","222");
if (departmentService.remove(departement)) {
System.out.println("删除成功！");
}else {
System.out.println("删除失败！");
}
System.out.println("-----------修改-----------");
departement=new Departement(6,"运维部");
if (departmentService.modify(departement)) {
System.out.println("修改成功！");
}else {
System.out.println("修改失败！");
}
System.out.println("-----------查询全部-----------");
List<Departement> list=departmentService.findAll();
for (Departement d:list) {
System.out.println(d.getDep_no()+"\t"+d.getDeo_name()+"\t"+d.getDep_loc());
}
System.out.println("-----------通过id查询-----------");
departement=new Departement(6,"运维部","223");
departement=departmentService.findById(departement);
System.out.println(departement.getDep_no()+"\t"+departement.getDeo_name()+"\t"+departement.getDep_loc());
*/
/* System.out.println("--------增加员工----------");
departement=new Departement(2);
employee=new Employee("mvc01","张大","男",20,departement);
if (employeeService.add(employee)) {
System.out.println("添加成功！");
}else{
System.out.println("添加失败！");
}*/
}
}
总结：外键字段可以看成主表对象，无论是赋值还是取值都用主表对象进行存取
二、日期时间处理
可以先编写日期时间转换的工具类：
package _15MVC.d01.cn.com.util;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* @author LX 日期和字符串时间转换工具类
* @create 2024-02-20 12:06
*/
public class DateOrString {
//方法声明成静态的，就可以直接用类名调用了
public static Date StrToDate(String str){
Date date=null;
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
try {//解析
date=sdf.parse(str);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
public static String DateTostr(Date date){
String str=null;
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
//格式化
str=sdf.format(date);
return str;
}
}
这里我们以年级表和学生表为例:
年级表我们已经完成，这里就不做展示了。主要看学生表中的日期时间处理：
1、学生实体：【时间属性声明为java.util.Date】
package _15MVC.d01.cn.com.entity;
import java.util.Date;
/**
* @author LX
* @create 2024-02-20 10:55
*/
public class Student {
private int stu_no;//编号
private String stu_pwd;//密码
private String stu_name;//姓名
private String stu_sex;//性别
private Grade grade;//年级编号，外键字段，使用对象表示
private String stu_phone;//电话
private String stu_add;//地址
private Date stu_born;//出生日期
private String stu_email;//邮箱
public Student() {
}
public Student(int stu_no, String stu_pwd, String stu_name, String stu_sex, Grade grade, String stu_phone, String stu_add, Date stu_born, String stu_email) {
this.stu_no = stu_no;
this.stu_pwd = stu_pwd;
this.stu_name = stu_name;
this.stu_sex = stu_sex;
this.grade = grade;
this.stu_phone = stu_phone;
this.stu_add = stu_add;
this.stu_born = stu_born;
this.stu_email = stu_email;
}
public int getStu_no() {
return stu_no;
}
public void setStu_no(int stu_no) {
this.stu_no = stu_no;
}
public String getStu_pwd() {
return stu_pwd;
}
public void setStu_pwd(String stu_pwd) {
this.stu_pwd = stu_pwd;
}
public String getStu_name() {
return stu_name;
}
public void setStu_name(String stu_name) {
this.stu_name = stu_name;
}
public String getStu_sex() {
return stu_sex;
}
public void setStu_sex(String stu_sex) {
this.stu_sex = stu_sex;
}
public Grade getGrade() {
return grade;
}
public void setGrade(Grade grade) {
this.grade = grade;
}
public String getStu_phone() {
return stu_phone;
}
public void setStu_phone(String stu_phone) {
this.stu_phone = stu_phone;
}
public String getStu_add() {
return stu_add;
}
public void setStu_add(String stu_add) {
this.stu_add = stu_add;
}
public Date getStu_born() {
return stu_born;
}
public void setStu_born(Date stu_born) {
this.stu_born = stu_born;
}
public String getStu_email() {
return stu_email;
}
public void setStu_email(String stu_email) {
this.stu_email = stu_email;
}
}
2、学生dao层接口
package _15MVC.d01.cn.com.dao;
import _15MVC.d01.cn.com.entity.Student;
import java.util.List;
/**
* @author LX
* @create 2024-02-20 12:08
*/
public interface StudentDao {
public int insert(Student student);
public int delete(Student student);
public int update(Student student);
public List<Student> selectAll();
}
3、学生dao的实现类【在给时间字段的占位符赋值时需要用时间戳】
package _15MVC.d01.cn.com.dao.impl;
import _15MVC.d01.cn.com.dao.BaseDao1;
import _15MVC.d01.cn.com.dao.StudentDao;
import _15MVC.d01.cn.com.entity.Grade;
import _15MVC.d01.cn.com.entity.Student;
import javax.management.OperationsException;
import java.sql.Date;
import java.sql.SQLException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
/**
* @author LX
* @create 2024-02-20 12:11
*/
public class StudentDaoImpl extends BaseDao1 implements StudentDao {
@Override
public int insert(Student student) {
int i=-1;
open();
String sql="insert into student(stu_no,stu_pwd,stu_name,stu_sex,grad_no,stu_phone,stu_add,stu_born,stu_email) values(?,?,?,?,?,?,?,?,?)";
try {
pst=con.prepareStatement(sql);
pst.setInt(1,student.getStu_no());
pst.setString(2,student.getStu_pwd());
pst.setString(3,student.getStu_name());
pst.setString(4,student.getStu_sex());
pst.setInt(5,student.getGrade().getGrade_no());
pst.setString(6,student.getStu_phone());
pst.setString(7,student.getStu_add());
//时间处理：
//在声明属性的时候，我们声明的Date是java.util.Date
//pst.setDate()这里使用的是java.sql.Date。我们就需要用new Date()转换一下
//new Date(student.getStu_born().getTime())转换后得到的是时间戳
pst.setDate(8, new Date(student.getStu_born().getTime()));
pst.setString(9,student.getStu_email());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
close();
}
return i;
}
@Override
public int delete(Student student) {
int i=-1;
open();
String sql="delete from student where stu_no=?";
try {
pst=con.prepareStatement(sql);
pst.setInt(1,student.getStu_no());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
close();
}
return i;
}
@Override
public int update(Student student) {
int i=-1;
open();
String sql="update student set stu_pwd=?,stu_born=? where stu_no=?";
try {
pst=con.prepareStatement(sql);
pst.setString(1,student.getStu_pwd());
pst.setDate(2,new Date(student.getStu_born().getTime()));
pst.setInt(3,student.getStu_no());
i=pst.executeUpdate();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
close();
}
return i;
}
public List<Student> selectAll() {
List<Student> list=null;
open();
String sql="select * from student";
try {
pst=con.prepareStatement(sql);
rs=pst.executeQuery();
list=new ArrayList<Student>();
while(rs.next()){
Student stu=new Student();
stu.setStu_no(rs.getInt("stu_no"));
stu.setStu_pwd(rs.getString("stu_pwd"));
stu.setStu_name(rs.getString("stu_name"));
stu.setStu_sex(rs.getString("stu_sex"));
Grade g=new Grade();
g.setGrade_no(rs.getInt("grad_no"));
stu.setGrade(g);
stu.setStu_phone(rs.getString("stu_phone"));
stu.setStu_add(rs.getString("stu_add"));
stu.setStu_born(rs.getDate("stu_born"));
stu.setStu_email(rs.getString("stu_email"));
list.add(stu);
}
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
close();
}
return list;
}
}
4、学生service层接口和实现层
package _15MVC.d01.cn.com.service;
import _15MVC.d01.cn.com.entity.Student;
import java.util.List;
/**
* @author LX
* @create 2024-02-20 15:23
*/
public interface StudentService {
public boolean add(Student student);
public boolean remove(Student student);
public boolean modify(Student student);
public List<Student> findAll();
}
package _15MVC.d01.cn.com.service.impl;
import _15MVC.d01.cn.com.dao.StudentDao;
import _15MVC.d01.cn.com.dao.impl.StudentDaoImpl;
import _15MVC.d01.cn.com.entity.Student;
import _15MVC.d01.cn.com.service.StudentService;
import java.util.List;
/**
* @author LX
* @create 2024-02-20 15:24
*/
public class StudentServiceImpl implements StudentService {
private StudentDao studentDao=new StudentDaoImpl();
public boolean add(Student student) {
return studentDao.insert(student)>0;
}
public boolean remove(Student student) {
return studentDao.delete(student)>0;
}
public boolean modify(Student student) {
return studentDao.update(student)>0;
}
public List<Student> findAll() {
return studentDao.selectAll();
}
}
5、测试类【给时间字段赋值时，可以使用SimpleDateFormat对象来转[case 12]，也可以使用时间工具类来转[case 32]】
package _15MVC.d01.cn.com.test;
import _15MVC.d01.cn.com.entity.Grade;
import _15MVC.d01.cn.com.entity.Student;
import _15MVC.d01.cn.com.service.GradeService;
import _15MVC.d01.cn.com.service.StudentService;
import _15MVC.d01.cn.com.service.impl.GradeServiceImpl;
import _15MVC.d01.cn.com.service.impl.StudentServiceImpl;
import _15MVC.d01.cn.com.util.DateOrString;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Scanner;
/**
* @author LX
* @create 2024-02-20 10:10
*/
public class TestGrade {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
int var=0;
boolean flag=false;
Grade grade=new Grade();
Student student=new Student();
GradeService gradeService=new GradeServiceImpl();
StudentService studentService=new StudentServiceImpl();
do {
System.out.println("----------*欢迎使用学生管理系统*----------");
System.out.println("----------*增加年级信息请按11*增加学生信息请按12*----------");
System.out.println("----------*删除年级信息请按21*删除学生信息请按22*----------");
System.out.println("----------*修改年级信息请按31*修改学生信息请按32*----------");
System.out.println("----------*查询所有年级信息请按41*查询所有学生信息请按42*----------");
System.out.println("----------*通过年级编号查询年级请按51*通过学生编号查询学生请按52*----------");
System.out.println("----------*结束使用请按0*----------");
System.out.println("----------*请输入你的选择：*----------");
var=input.nextInt();
switch (var){
case 11:
System.out.println("您选择的是增加年级信息：");
System.out.println("请输入年级编号：");
int gradeNo=input.nextInt();
System.out.println("请输入年级名称：");
String gradeName=input.next();
System.out.println("请输入年级人数：");
int gradeNum=input.nextInt();
grade.setGrade_no(gradeNo);
grade.setGrade_name(gradeName);
grade.setGrade_num(gradeNum);
flag=gradeService.add(grade);
if (flag){
System.out.println("增加年级信息成功！");
}else{
System.out.println("增加年级信息失败！");
}
break;
case 12:
System.out.println("您选择的是增加学生信息：");
System.out.println("请输入学生编号：");
int stu_no=input.nextInt();
System.out.println("请输入学生密码");
String stu_pwd=input.next();
System.out.println("请输入学生姓名");
String stu_name=input.next();
System.out.println("请输入学生性别");
String stu_sex=input.next();
System.out.println("请输入年级编号");
gradeNo=input.nextInt();
grade.setGrade_no(gradeNo);
System.out.println("请输入学生电话");
String stu_phone=input.next();
System.out.println("请输入学生地址");
String stu_add=input.next();
System.out.println("请输入学生出生日期");
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Date stu_born=null;//要在外部声明，不然在try{}中声明就会变成局部变量
try {
stu_born= sdf.parse(input.next());
} catch (ParseException e) {
e.printStackTrace();
}
System.out.println("请输入学生邮箱");
String stu_email=input.next();
student.setStu_no(stu_no);
student.setStu_pwd(stu_pwd);
student.setStu_name(stu_name);
student.setStu_sex(stu_sex);
student.setGrade(grade);
student.setStu_phone(stu_phone);
student.setStu_add(stu_add);
student.setStu_born(stu_born);
student.setStu_email(stu_email);
flag=studentService.add(student);
if (flag){
System.out.println("增加学生信息成功！");
}else{
System.out.println("增加学生信息失败！");
}
break;
case 21:
System.out.println("您选择的是删除年级信息：");
System.out.println("请输入要删除的年级编号：");
gradeNo=input.nextInt();
grade.setGrade_no(gradeNo);
flag=gradeService.remove(grade);
if (flag){
System.out.println("删除年级信息成功！");
}else{
System.out.println("删除年级信息失败！");
}
break;
case 22:
System.out.println("您选择的是删除学生信息：");
System.out.println("请输入要删除的学生编号：");
stu_no=input.nextInt();
student.setStu_no(stu_no);
flag=studentService.remove(student);
if (flag){
System.out.println("删除学生信息成功！");
}else{
System.out.println("删除学生信息失败！");
}
break;
case 31:
System.out.println("您选择的是修改年级信息：");
System.out.println("请输入要修改的年级编号：");
gradeNo=input.nextInt();
System.out.println("请输入要修改的年级人数：");
gradeNum=input.nextInt();
grade.setGrade_no(gradeNo);
grade.setGrade_num(gradeNum);
flag=gradeService.modify(grade);
if (flag){
System.out.println("修改年级信息成功！");
}else{
System.out.println("修改年级信息失败！");
}
break;
case 32:
System.out.println("您选择的是修改学生信息：");
System.out.println("请输入要修改的学生编号：");
stu_no=input.nextInt();
System.out.println("请输入修改的新密码：");
stu_pwd=input.next();
System.out.println("请输入修改后的出生日期：");
/*stu_born=null;
sdf=new SimpleDateFormat("yyyy-MM-dd");
try {
stu_born=sdf.parse(input.next());
} catch (ParseException e) {
e.printStackTrace();
}*/
student.setStu_no(stu_no);
student.setStu_pwd(stu_pwd);
// student.setStu_born(stu_born);
//使用工具类与不使用的区别
student.setStu_born(DateOrString.StrToDate(input.next()));
flag=studentService.modify(student);
if (flag){
System.out.println("修改学生信息成功！");
}else{
System.out.println("修改学生信息失败！");
}
break;
case 41:
System.out.println("您选择的是查询年级信息：");
List<Grade> list=gradeService.findAll();
for (Grade g:list){
System.out.println(g.getGrade_no()+"\t"+g.getGrade_name()+"\t"+g.getGrade_num());
}
break;
case 42:
System.out.println("您选择的是查询学生信息：");
List<Student> list1=studentService.findAll();
for (Student stu:list1){ System.out.println(stu.getStu_no()+"\t"+stu.getStu_pwd()+"\t"+stu.getStu_name()+"\t"+stu.getStu_sex()+"\t"+stu.getStu_phone()+"\t"+stu.getGrade().getGrade_no()+"\t"+stu.getStu_add()+"\t"+stu.getStu_born()+"\t"+stu.getStu_email());
}
break;
}
}while (var!=0);
}
}
总结：日期时间字段在处理时，可以提前写一个工具类
在给时间字段赋值时，就可以用工具类把字符串时间转换成Date类型的时间
扫一扫
524
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
