【数据库】学生管理系统
☞本项目主要练习MySQL数据库和java代码之间的连通☜
☞后续会在本基础上，利用Spring实现WEB端☜
☞梦想进大厂的一只程序猿☜
☞期望毕业前力扣刷够400题☜
☞正在复习数据结构和算法☜
☞博客地址：https://www.huangliangshuai.com/☜
1. 项目架构图
2. 系统分析
2.1. 数据库
2.1.1. 表student
2.2 java端
2.2.1 JBDC
2.2.1.1JDBC连接
package com.situ.student.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;
public class JDBCUtil {
private static ResourceBundle rb = ResourceBundle.getBundle("com.situ.student.util.JDBC");
private static String cLassName = rb.getString("driver");
private static String url = rb.getString("url");
private static String user = rb.getString("user");
private static String password = rb.getString("pass");
// 1- 加载驱动
static {
try {
Class.forName(cLassName);
} catch (Exception e) {
e.getCause();
}
}
// 2- 获得链接
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(url, user, password);
}
public static void close(Connection conn, Statement st, ResultSet rs) {
try {
if (rs != null) {
rs.close();
rs = null;
}
if (st != null) {
st.close();
st = null;
}
if (conn != null) {
conn.close();
conn = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Connection conn, Statement st) {
close(conn, st, null);
}
public static void main(String[] args) throws SQLException {
// 加载驱动 + 获得链接
Connection con = JDBCUtil.getConnection();
System.out.println(con);
JDBCUtil.close(con, null); // 关闭的是插入的
}
private JDBCUtil() {
}
}
2.2.1.1JDBC配置文件
pass=123456
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3308/demo01?useSSL=false&useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Hongkong&allowPublicKeyRetrieval=true
2.2.2 student包
2.2.2.1 Model
package com.situ.student.student.model;
public class StudentModel {
private String id;
private String name;
private String age;
private String profession;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String getProfession() {
return profession;
}
public void setProfession(String profession) {
this.profession = profession;
}
@Override
public String toString() {
return "StudentModel [id=" + id + ", name=" + name + ", age=" + age + ", profession=" + profession + "]";
}
}
2.2.2.2 Dao
package com.situ.student.student.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.situ.student.student.model.StudentModel;
import com.situ.student.util.JDBCUtil;
public class StudentDao {
private Connection connection = null;
private PreparedStatement ps = null;
// 增加
public String insert(StudentModel model) {
String sql = "insert into student(s_id, name, age, profession) value(?,?,?,?)";
try {
connection = JDBCUtil.getConnection(); // 获得链接
ps = connection.prepareStatement(sql); // 执行SQL
ps.setString(1, model.getId()); // 填充问号
ps.setString(2, model.getName());
ps.setString(3, model.getAge());
ps.setString(4, model.getProfession());
int res = ps.executeUpdate(); // 返回改变的记录条数
return res + "";
} catch (SQLException e) {
e.printStackTrace();
} finally {
JDBCUtil.close(connection, ps);
}
return -1 + "";
}
// 删除
public String delete(StudentModel model) {
String sql = "delete from student where s_id = ?";
try {
connection = JDBCUtil.getConnection();
ps = connection.prepareStatement(sql);
ps.setString(1, model.getId());
int res = ps.executeUpdate();
return res + "";
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.close(connection, ps);
}
return -1 + "";
}
// 修改
public String update(StudentModel model) {
String sql = "update student set profession = ? where s_id = ?";
try {
connection = JDBCUtil.getConnection();
ps = connection.prepareStatement(sql);
ps.setString(1, model.getProfession());
ps.setString(2, model.getId());
int res = ps.executeUpdate();
return res + "";
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.close(connection, ps);
}
return -1 + "";
}
// 查询
public List<StudentModel> select(StudentModel model) {
StringBuffer sql = new StringBuffer("select s_id, name, age, profession from student where 1 = 1");
List<Object> list = new ArrayList<Object>();
list = where(sql, model);
List<StudentModel> list2 = new ArrayList<StudentModel>();
ResultSet set = null;
try {
connection = JDBCUtil.getConnection();
ps = connection.prepareStatement(sql.toString());
for (int i = 0; i < list.size(); i++) {
ps.setObject(i + 1, list.get(i));
}
set = ps.executeQuery();
while (set.next()) {
StudentModel model1 = new StudentModel();
model1.setId(set.getString("s_id"));
model1.setName(set.getString("name"));
model1.setAge(set.getString("age"));
model1.setProfession(set.getString("profession"));
list2.add(model1);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.close(connection, ps);
}
return list2;
}
public List<Object> where(StringBuffer sql, StudentModel model) {
String s_id = model.getId();
List<Object> list = new ArrayList<Object>();
if (s_id != null && !s_id.trim().isEmpty()) {
sql.append(" and s_id=?");
list.add(s_id);
}
String name = model.getName();
if (name != null && !name.trim().isEmpty()) {
sql.append(" and name = ?");
list.add(name);
}
String age = model.getAge();
if (age != null && !age.trim().isEmpty()) {
sql.append(" and age = ?");
list.add(age);
}
String profession = model.getProfession();
if (profession != null && !profession.trim().isEmpty()) {
sql.append(" and profession = ?");
list.add(profession);
}
return list;
}
}
2.2.2.3 Service
package com.situ.student.student.service;
import java.util.ArrayList;
import java.util.List;
import com.situ.student.student.dao.StudentDao;
import com.situ.student.student.model.StudentModel;
public class StudentService {
private StudentDao dao = new StudentDao();
public String insert(StudentModel model) {
StudentModel model2 = new StudentModel();
model2.setId(model.getId());
List<StudentModel> list = new ArrayList<StudentModel>();
list = dao.select(model);
if (list == null || list.isEmpty()) {
dao.insert(model);
return "插入成功！";
}
return "已经存在！";
}
public String delete(StudentModel model) {
return dao.delete(model);
}
public String update(StudentModel model) {
return dao.update(model);
}
public List<StudentModel> selectList(StudentModel model) {
return dao.select(model);
}
public StudentModel selcetModel(StudentModel model) {
StudentModel model2 = new StudentModel();
model2.setId(model.getId());
List<StudentModel> list = new ArrayList<StudentModel>();
list = dao.select(model);
if (list == null || list.isEmpty()) {
return null;
}
return list.get(0);
}
}
2.2.2 Test
package com.situ.student.student.studenttest;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import com.situ.student.student.model.StudentModel;
import com.situ.student.student.service.StudentService;
public class StudentTset {
private Scanner scanner = new Scanner(System.in);
boolean p = true;
private StudentService service = new StudentService();
public static void main(String[] args) {
StudentTset test = new StudentTset();
test.start();
}
public void start() {
while (p) {
System.out.println("1. 添加学生信息");
System.out.println("2. 按学生姓名查询学生信息");
System.out.println("3. 修改学生的专业(转专业)");
System.out.println("4. 按专业查询学生信息");
System.out.println("5. 查询所有人的信息");
System.out.println("6. 退出");
System.out.println("请输入你要");
String string = scanner.nextLine();
sart_1(string);
}
}
public void sart_1(String string) {
if (string.equals("1")) {
addStudent();
} else if (string.equals("2")) {
queryNameStudent();
} else if (string.equals("3")) {
setStudentProfessional();
} else if (string.equals("4")) {
queryProfessionalStudent();
} else if (string.equals("5")) {
querySumInformation();
} else if (string.equals("6")) {
p = false;
System.out.println("已为你退出系统！");
} else {
System.out.println("你的输入有误！");
}
}
public void addStudent() {
StudentModel model = new StudentModel();
System.out.println("请输入学生的编号：");
String id = scanner.nextLine();
System.out.println("请输入学生的名字：");
String name = scanner.nextLine();
System.out.println("请输入学生的年龄：");
String age = scanner.nextLine();
System.out.println("请输入学生的专业：");
String profession = scanner.nextLine();
model.setId(id);
model.setName(name);
model.setAge(age);
model.setProfession(profession);
System.out.println(service.insert(model));
}
// 按名字进行查询
public void queryNameStudent() {
System.out.println("请输入你要查询的名字：");
String name = scanner.nextLine();
StudentModel model = new StudentModel();
model.setName(name);
List<StudentModel> list = new ArrayList<StudentModel>();
list = service.selectList(model);
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
}
public void querySumInformation() {
StudentModel model = new StudentModel();
List<StudentModel> list = new ArrayList<StudentModel>();
list = service.selectList(model);
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
}
public void setStudentProfessional() {
StudentModel model = new StudentModel();
System.out.println("请输入你要修改的学生编号：");
String id = scanner.nextLine();
model.setId(id);
System.out.println("请输入你要转的专业：");
String profession = scanner.nextLine();
model.setProfession(profession);
service.update(model);
}
public void queryProfessionalStudent() {
System.out.println("请输入你要查询的专业：");
StudentModel model = new StudentModel();
String profession = scanner.nextLine();
model.setProfession(profession);
List<StudentModel> list = new ArrayList<StudentModel>();
list = service.selectList(model);
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
}
}