1.项目目录介绍
entity包为Javabean类，里面存放了Student表的信息
Student.java
package com.a_studentsys.entity;/*** @author Anonymous 2020/3/25 10:59*/
public class Student {private Integer id;private String name;private Integer age;private Boolean gender;private Float score;private String address;public Student() {}public Student(String name, Integer age, Boolean gender, Float score, String address) {this.name = name;this.age = age;this.gender = gender;this.score = score;this.address = address;}public Student(Integer id, String name, Integer age, Boolean gender, Float score, String address) {this.id = id;this.name = name;this.age = age;this.gender = gender;this.score = score;this.address = address;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Boolean getGender() {return gender;}public void setGender(Boolean gender) {this.gender = gender;}public Float getScore() {return score;}public void setScore(Float score) {this.score = score;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}@Overridepublic String toString() {return "Student{" +"id=" + id +", name='" + name + '\'' +", age=" + age +", gender=" + gender +", score=" + score +", address='" + address + '\'' +'}';}
}
controller包为控制层，
StudentController.java
package controller;import com.a_studentsys.entity.Student;
import service.StudentService;
import service.impl.StudentServiceImpl;
import view.StudentView;
import view.impl.StudentViewImpl;import java.math.BigDecimal;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;public class StudentController {/*StudentServiceImpl层实现类对象，提供服务*/private StudentService studentService = new StudentServiceImpl();/*studentView 界面层实现类对象，童工界面展示*/private StudentView studentView = new StudentViewImpl();private Scanner scanner =new Scanner(System.in);public void addStudent(){studentView.inputStudentName();String name =scanner.next();studentView.inputStudentAge();int age = scanner.nextInt();studentView.inputStudentGender();boolean gender = scanner.nextBoolean();studentView.inputStudentScore();float score = scanner.nextFloat();studentView.inputStudentAddress();String address = scanner.next();Student student = new Student(name, age, gender, score, address);studentService.addStudent(student);}public void deleteStudent(){studentView.inputStudentId();int id =scanner.nextInt();Student student = studentService.findStudentById(id);if (null == student){studentView.notFound();return;}studentView.showStudentInfo(student);studentView.deleteConfirm();if (scanner.nextBoolean()){studentService.deleteStudentById(id);}else {studentView.operationCancel();}}public void modifyStudentById(){studentView.inputStudentId();int id= scanner.nextInt();Student student = studentService.findStudentById(id);if (null == student){studentView.notFound();return;}int choose =0;boolean flag = false;while (true){studentView.modifyStudentMenu(student);choose= scanner.nextInt();switch (choose){case 1:studentView.inputStudentName();String name = scanner.next();student.setName(name);break;case 2:studentView.inputStudentAge();int age = scanner.nextInt();student.setAge(age);break;case 3:studentView.inputStudentGender();boolean gender = scanner.nextBoolean();student.setGender(gender);break;case 4:studentView.inputStudentScore();float score = scanner.nextFloat();student.setScore(score);break;case 5:studentView.inputStudentAddress();String address = scanner.next();student.setAddress(address);break;case 6:flag = true;break;default:break;}if (flag){studentService.updateStudent(student);break;}}}public void findStudentId(){studentView.inputStudentId();int id = scanner.nextInt();Student student = studentService.findStudentById(id);if (student !=null){studentView.showStudentInfo(student);}else {studentView.notFound();}}public void findAllStudent(){List<Student> list = studentService.findAllStudents();if (list != null){studentView.showStudentList(list);}else {studentView.notFound();}}/*** 按照条件排序*/public void sort() {studentView.sortOperationChoose();int choose = scanner.nextInt();List<Student> list = null;switch (choose) {case 1:// 年龄升序list = studentService.sortUsingCompare(Comparator.comparingInt(Student::getAge));break;case 2:// 成绩降序list = studentService.sortUsingCompare((stu1, stu2) -> {BigDecimal bigDecimal1 = new BigDecimal(stu1.getScore() + "");BigDecimal bigDecimal2 = new BigDecimal(stu2.getScore() + "");return bigDecimal2.compareTo(bigDecimal1);});break;default:studentView.chooseError();break;}if (list != null) {studentView.showStudentList(list);} else {studentView.notFound();}}public void mainMenu(){studentView.mainMenu();}public void chooseError(){studentView.chooseError();}
}
dao包是dao层
StudentDao.java
package dao;import com.a_studentsys.entity.Student;import java.util.List;public interface StudentDao {/*增删改查：1.查单个2.查所有*//*** 添加学生方法要求，参数为Student类对象，返回值为int类型，成功返回1 失败返回0* @param student Student类对象* @return 添加成功返回1 失败返回0*/int addStudent(Student student);/*** 根据指定的id删除对应的学生* @param id 指定的id* @return 删除成功返回1 失败返回0*/int deleteStudent(int id);/*** 修改学生信息，传入的参数是个Student类对象* @param student Student类对象* @return 更新成功返回1 失败返回0*/int updateStudent(Student student);/*** 查询指定id的学生* 没有找到返回null* @param id* @return 查询陈宫返回Student类对象，失败返回null*/Student findStudentById(int id);/*** 查询当前数据库中所有学生信息* @return 成功返回List集合 如果没有数据返回null*/List<Student> findAllStudent();}
StudentDaoImpl.java
package dao.impl;import com.a_studentsys.entity.Student;
import dao.StudentDao;
import util.BaseDao;import java.util.List;/*** 这里需要继承BaseDao对于数据库操作的Update Query方法* 同时遵从StudentDao接口，完成方法实现，当前类使用一个符合StudentDao规范的实现类*/
public class StudentDaoImpl extends BaseDao implements StudentDao {@Overridepublic int addStudent(Student student) {String sql = "insert into test.student(name, age, gender, score, address) value (?,?,?,?,?)";Object[] parameters = {student.getName(),student.getAge(),student.getGender(),student.getScore(),student.getAddress()};return super.update(sql,parameters);}@Overridepublic int deleteStudent(int id) {String sql = "delete from test.student where id= "+id;return super.update(sql,null);}@Overridepublic int updateStudent(Student student) {String sql = "update test.student set name=?,age=?,gender=?,score=?,address=? where id=?";Object[] parameters = {student.getName(),student.getAge(),student.getGender(),student.getScore(),student.getAddress(),student.getId()};return super.update(sql,parameters);}@Overridepublic Student findStudentById(int id) {String sql="select * from test.student where id="+id;Student student = super.queryBean(sql, null, Student.class);return student;}@Overridepublic List<Student> findAllStudent() {String sql="select * from test.student";return super.queryBeanList(sql, null, Student.class);}
}
main包里包含main方法
mainProject.java
package main;import controller.StudentController;import java.util.Scanner;public class mainProject {/*View界面*/private static Scanner scanner = new Scanner(System.in);private static StudentController studentController = new StudentController();public static void main(String[] args) {int choose = 0;boolean flag = false;while (flag){studentController.mainMenu();choose = scanner.nextInt();switch (choose){case 1:studentController.addStudent();break;case 2:studentController.deleteStudent();break;case 3:studentController.modifyStudentById();break;case 4:studentController.findStudentId();break;case 5:studentController.findAllStudent();break;case 6:studentController.sort();break;case 7:flag=flag;break;default:studentController.chooseError();break;}}}
}
service包是服务层，包括了服务以及服务的实现类
StudentService.java
package service;import com.a_studentsys.entity.Student;import java.util.Comparator;
import java.util.List;public interface StudentService {/*增删改查排序*//*** Service层规定的添加学生方法，返回值类型是boolean** @param student Student类对象* @return 添加成功返回true，失败返回false*/boolean addStudent(Student student);/*** 删除指定ID学生** @param id 指定学生的ID* @return 删除成功返回true，失败返回false*/boolean deleteStudentById(Integer id);/*** 更新学生信息** @param student 需要更新信息的一个Student类对象* @return 更新成功返回true，失败返回false*/boolean updateStudent(Student student);/*** 查询指定ID的学生** @param id 指定的学生的ID号* @return Student类对象，没有找到返回null*/Student findStudentById(Integer id);/*** 查询所有的学生类对象，存储于List集合中** @return List集合，没有数据返回null*/List<Student> findAllStudents();/*** 按照提供的方法，排序学生信息保存到List集合中** @param comparator Comparator函数式接口要求规范* @return List集合，排序之后的学生数据，没有数据返回null*/List<Student> sortUsingCompare(Comparator<Student> comparator);}
StudentServiceImpl.java
package service.impl;import com.a_studentsys.entity.Student;
import dao.StudentDao;
import dao.impl.StudentDaoImpl;
import service.StudentService;import java.util.Comparator;
import java.util.List;public class StudentServiceImpl implements StudentService {/*准备一个StudentDao层的实现类对象，帮助操作数据库*/StudentDao studentDao = new StudentDaoImpl();@Overridepublic boolean addStudent(Student student) {return studentDao.addStudent(student) !=0;}@Overridepublic boolean deleteStudentById(Integer id) {return studentDao.deleteStudent(id) !=0;}@Overridepublic boolean updateStudent(Student student) {return studentDao.updateStudent(student) !=0;}@Overridepublic Student findStudentById(Integer id) {return studentDao.findStudentById(id);}@Overridepublic List<Student> findAllStudents() {return studentDao.findAllStudent();}@Overridepublic List<Student> sortUsingCompare(Comparator<Student> comparator) {List<Student> list = studentDao.findAllStudent();if (list != null){list.sort(comparator);}return list;}
}
util包里是工具包，封装了数据库的增删改查方法
BaseDao.java
package util;import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ArrayListHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;/*** BaseDao 数据库操作基类* 1. 通用更新* 2. 通用查询** @author Anonymous 2020/3/24 16:01*/
public class BaseDao {/*** 通用的更新方法，需要参数是SQL语句和对应当前SQL语句的Object类型参数数组** @param sql String类型的SQL语句，需要执行的方法* @param parameters 对应当前SQL语句的参数列表。Object类型数组* @return SQL语句执行数据库受到影响的行数*/public int update(String sql, Object[] parameters) {// DbUtils核心类，QueryRunnerQueryRunner runner = new QueryRunner();Connection connection = JdbcUtil.getConnection();int affectedRows = 0;try {affectedRows = runner.update(connection, sql, parameters);} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtil.close(connection);}return affectedRows;}/*** 通用的查询方法，查询cls指定数据类型，单一对象** @param sql Select SQL语句* @param parameters 对应当前SQL语句的参数* @param cls 指定数据类型，同时提供Class对象，便于里用反射操作，约束泛型类型* @param <T> 泛型占位符* @return 单一指定类型对象，没有找到返回null*/public <T> T queryBean(String sql, Object[] parameters, Class<T> cls) {// DbUtils核心类，QueryRunnerQueryRunner runner = new QueryRunner();Connection connection = JdbcUtil.getConnection();T t = null;try {t = runner.query(connection, sql, new BeanHandler<>(cls), parameters);} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtil.close(connection);}return t;}/*** 通用的查询方法，查询cls指定数据类型，包含指定对象的List集合** @param sql Select SQL语句* @param parameters 对应当前SQL语句的参数* @param cls 指定数据类型，同时提供Class对象，便于里用反射操作，约束泛型类型* @param <T> 泛型占位符* @return 返回包含指定对象的List集合，没有数据返回null*/public <T> List<T> queryBeanList(String sql, Object[] parameters, Class<T> cls) {// DbUtils核心类，QueryRunnerQueryRunner runner = new QueryRunner();Connection connection = JdbcUtil.getConnection();List<T> list = null;try {list = runner.query(connection, sql, new BeanListHandler<>(cls), parameters);} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtil.close(connection);}return list;}/*** 通用查询方法，返回值是对应字段数据的Object类型数组，并且存储于List集合** @param sql Select查询SQL语句* @param parameters 对应当前SQL语句的参数* @return 包含数据行数据的List<Object[]> 如果没有查询到数据，返回null*/public List<Object[]> queryArrayList(String sql, Object[] parameters) {QueryRunner runner = new QueryRunner();Connection connection = JdbcUtil.getConnection();List<Object[]> list = null;try {list = runner.query(connection, sql, new ArrayListHandler(), parameters);} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtil.close(connection);}return list;}
}
JdbcUtil.java
package util;import java.io.FileInputStream;
import java.io.IOException;
import java.sql.*;
import java.util.Properties;/*** JDBC工具类，负责数据库连接对象和数据库资源关闭** @author Anonymous 2020/3/24 10:08*/
public class JdbcUtil {// 静态成员变量，保存一些必要的数据private static String url = null;private static String user = null;private static String password = null;// 利用static修饰的静态代码块完成文件字段自动读取和驱动自动加载过分static {try {// Properties实现类，里面的数据保存形式都是键值对形式Properties properties = new Properties();// 使用字节输入流，加载对应db.properties，数据保存到Properties对象中properties.load(new FileInputStream("./src/db.properties"));// 从Properties读取对应的数据String driverClass = properties.getProperty("driverClass");url = properties.getProperty("url");user = properties.getProperty("user");password = properties.getProperty("password");// 完整驱动加载Class.forName(driverClass);} catch (IOException | ClassNotFoundException e) {e.printStackTrace();}}/*** 返回数据库连接对象，连接失败返回null** @return java.sql.Connection 数据库连接对象*/public static Connection getConnection() {Connection connection = null;try {// 通过DriverManager驱动管理类，使用必要参数获取数据库连接connection = DriverManager.getConnection(url, user, password);} catch (SQLException e) {e.printStackTrace();}return connection;}/*以下三个方法实际上都是执行同一个方法，使用这种方式1. 简化代码结构2. 规范化所有的操作*//*** 处理数据库操作对应的资源问题** @param connection java.sql.Connection 数据库连接对象*/public static void close(Connection connection) {close(connection, null, null);}/*** 处理数据库操作对应的资源问题** @param connection java.sql.Connection 数据库连接对象* @param statement java.sql.Statement 数据库SQL语句搬运工对象*/public static void close(Connection connection, Statement statement) {close(connection, statement, null);}/*** 处理数据库操作对应的资源问题** @param connection java.sql.Connection 数据库连接对象* @param statement java.sql.Statement 数据库SQL语句搬运工对象* @param resultSet java.sql.ResultSet 数据库查询结果集对象*/public static void close(Connection connection, Statement statement, ResultSet resultSet) {try {if (resultSet != null) {resultSet.close();}if (statement != null) {statement.close();}if (connection != null) {connection.close();}} catch (SQLException e) {e.printStackTrace();}}
}
view为视图层
StudentView.java
package view;import com.a_studentsys.entity.Student;import java.util.List;public interface StudentView {/*** 提示用户输入ID*/void inputStudentId();/*** 提示用户输入醒目*/void inputStudentName();/*** 提示用户输入年龄*/void inputStudentAge();/*** 提示用户输入性别*/void inputStudentGender();/*** 提示用户输入成绩*/void inputStudentScore();/*** 提示用户输入住址*/void inputStudentAddress();/*** 展示一个学生信息** @param student Student类对象*/void showStudentInfo(Student student);/*** 删除确认提示*/void deleteConfirm();/*** 操作取消*/void operationCancel();/*** Not Found!!! ==> 404*/void notFound();/*** 展示List集合的中的Student类对象* @param students List集合*/void showStudentList(List<Student> students);/*** 排序选择提示*/void sortOperationChoose();/*** 修改学生菜单* @param student Student*/void modifyStudentMenu(Student student);/*** 选择错误提示*/void chooseError();/*** 主菜单，主界面*/void mainMenu();}
StudentViewImpl.java
package view.impl;import com.a_studentsys.entity.Student;
import view.StudentView;import java.util.List;/*** @author Anonymous 2020/3/25 11:36*/
public class StudentViewImpl implements StudentView {@Overridepublic void inputStudentId() {System.out.println("请输入学生的ID号:");}@Overridepublic void inputStudentName() {System.out.println("请输入学生的姓名:");}@Overridepublic void inputStudentAge() {System.out.println("请输入学生的年龄:");}@Overridepublic void inputStudentGender() {System.out.println("请输入学生的性别 true => 男 false => 女:");}@Overridepublic void inputStudentScore() {System.out.println("请输入学生的成绩:");}@Overridepublic void inputStudentAddress() {System.out.println("请输入学生的地址:");}@Overridepublic void showStudentInfo(Student student) {System.out.println(student);}@Overridepublic void deleteConfirm() {System.out.println("确定删除吗? true or false");}@Overridepublic void operationCancel() {System.out.println("操作取消");}@Overridepublic void notFound() {System.out.println("查无此人");}@Overridepublic void showStudentList(List<Student> students) {for (Student student : students) {System.out.println(student);}}@Overridepublic void sortOperationChoose() {System.out.println("1. 年龄升序");System.out.println("2. 成绩降序");}@Overridepublic void modifyStudentMenu(Student student) {System.out.println("ID:" + student.getId() + " Name:" + student.getName());System.out.println("Age:" + student.getAge() + " Gender:" + (student.getGender() ? "男" : "女"));System.out.println("Score:" + student.getScore() + " Address:" + student.getAddress());System.out.println("1. 修改学生的名字");System.out.println("2. 修改学生的年龄");System.out.println("3. 修改学生的性别");System.out.println("4. 修改学生的成绩");System.out.println("5. 修改学生的地址");System.out.println("6. 退出保存");}@Overridepublic void chooseError() {System.out.println("选择错误！！！");}@Overridepublic void mainMenu() {System.out.println("1. 添加学生");System.out.println("2. 删除指定ID学生");System.out.println("3. 修改指定ID学生");System.out.println("4. 查询指定ID学生");System.out.println("5. 查询所有学生");System.out.println("6. 按照条件排序学生信息");System.out.println("7. 退出");}
}
最后的连接驱动db.properties
# 当前JDBC连接所需的驱动
driverClass=com.mysql.jdbc.Driver# 数据库连接符合JDBC规范的url
url=jdbc:mysql://localhost:3306/test?useSSL=true# 用户名
user=root# 密码
password=root
结果
