Java入门项目：家庭财务管理系统
Java入门项目：家庭财务管理系统（mysql+javase）
前言
此项目由MYSQL(druidJDBC)+JavaSE所编写的简单入门项目
家庭财务管理系统实现思路
- 准备连接数据库文件druid.properties、basicDAO和相应的工具类
- 创建user和bill表并定义相应的映射类
- 编写BasicDAO子类BillDAO和UserDAO类
- 主界面的编写
- UserService类的crud
- BillService类的crud
准备连接数据库文件druid.properties、basicDAO和相应的工具类
druid.properties
#key=value driverClassName=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/test02?rewriteBatchedStatements=true username=root password=lmt #initial connection Size initialSize=10 #min idle connecton size minIdle=5 #max active connection size maxActive=50 #max wait time (5000 mil seconds) maxWait=5000
basicDAO
package com.rogue.dao;import com.rogue.utils.JDBCUtilsByDruid; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanHandler; import org.apache.commons.dbutils.handlers.BeanListHandler; import org.apache.commons.dbutils.handlers.ScalarHandler;import java.sql.Connection; import java.sql.SQLException; import java.util.List;/*** 开发BasicDAO , 是其他DAO的父类*/ public class BasicDAO<T> { //泛型指定具体类型private QueryRunner qr = new QueryRunner();//开发通用的dml方法, 针对任意的表public int update(String sql, Object... parameters) {Connection connection = null;try {connection = JDBCUtilsByDruid.getConnection();int update = qr.update(connection, sql, parameters);return update;} catch (SQLException e) {throw new RuntimeException(e); //将编译异常->运行异常 ,抛出} finally {JDBCUtilsByDruid.close(null, null, connection);}}//返回多个对象(即查询的结果是多行), 针对任意表/**** @param sql sql 语句，可以有 ?* @param clazz 传入一个类的Class对象 比如 Actor.class* @param parameters 传入 ? 的具体的值，可以是多个* @return 根据Actor.class 返回对应的 ArrayList 集合*/public List<T> queryMulti(String sql, Class<T> clazz, Object... parameters) {Connection connection = null;try {connection = JDBCUtilsByDruid.getConnection();return qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);} catch (SQLException e) {throw new RuntimeException(e); //将编译异常->运行异常 ,抛出} finally {JDBCUtilsByDruid.close(null, null, connection);}}//查询单行结果 的通用方法public T querySingle(String sql, Class<T> clazz, Object... parameters) {Connection connection = null;try {connection = JDBCUtilsByDruid.getConnection();return qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);} catch (SQLException e) {throw new RuntimeException(e); //将编译异常->运行异常 ,抛出} finally {JDBCUtilsByDruid.close(null, null, connection);}}//查询单行单列的方法,即返回单值的方法public Object queryScalar(String sql, Object... parameters) {Connection connection = null;try {connection = JDBCUtilsByDruid.getConnection();return qr.query(connection, sql, new ScalarHandler(), parameters);} catch (SQLException e) {throw new RuntimeException(e); //将编译异常->运行异常 ,抛出} finally {JDBCUtilsByDruid.close(null, null, connection);}} }
Utils
package com.rogue.utils;/**工具类的作用:处理各种情况的用户输入，并且能够按照程序员的需求，得到用户的控制台输入。 */import java.util.Scanner;public class Utility {//静态属性。。。private static Scanner scanner = new Scanner(System.in);/*** 功能：读取键盘输入的一个菜单选项，值：1——5的范围* @return 1——5*/public static char readMenuSelection() {char c;for (; ; ) {String str = readKeyBoard(1, false);//包含一个字符的字符串c = str.charAt(0);//将字符串转换成字符char类型if (c != '1' && c != '2' && c != '3' && c != '4' && c != '5') {System.out.print("选择错误，请重新输入：");} else break;}return c;}/*** 功能：读取键盘输入的一个字符* @return 一个字符*/public static char readChar() {String str = readKeyBoard(1, false);//就是一个字符return str.charAt(0);}/*** 功能：读取键盘输入的一个字符，如果直接按回车，则返回指定的默认值；否则返回输入的那个字符* @param defaultValue 指定的默认值* @return 默认值或输入的字符*/public static char readChar(char defaultValue) {String str = readKeyBoard(1, true);//要么是空字符串，要么是一个字符return (str.length() == 0) ? defaultValue : str.charAt(0);}/*** 功能：读取键盘输入的整型，长度小于2位* @return 整数*/public static int readInt() {int n;for (; ; ) {String str = readKeyBoard(2, false);//一个整数，长度<=2位try {n = Integer.parseInt(str);//将字符串转换成整数break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的 整数或默认值，如果直接回车，则返回默认值，否则返回输入的整数* @param defaultValue 指定的默认值* @return 整数或默认值*/public static int readInt(int defaultValue) {int n;for (; ; ) {String str = readKeyBoard(10, true);if (str.equals("")) {return defaultValue;}//异常处理...try {n = Integer.parseInt(str);break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的指定长度的字符串* @param limit 限制的长度* @return 指定长度的字符串*/public static String readString(int limit) {return readKeyBoard(limit, false);}/*** 功能：读取键盘输入的指定长度的字符串或默认值，如果直接回车，返回默认值，否则返回字符串* @param limit 限制的长度* @param defaultValue 指定的默认值* @return 指定长度的字符串*/public static String readString(int limit, String defaultValue) {String str = readKeyBoard(limit, true);return str.equals("")? defaultValue : str;}/*** 功能：读取键盘输入的确认选项，Y或N* 将小的功能，封装到一个方法中.* @return Y或N*/public static char readConfirmSelection() {System.out.print("确认是否预订(Y/N): ");char c;for (; ; ) {//无限循环//在这里，将接受到字符，转成了大写字母//y => Y n=>NString str = readKeyBoard(1, false).toUpperCase();c = str.charAt(0);if (c == 'Y' || c == 'N') {break;} else {System.out.print("选择错误，请重新输入：");}}return c;}/*** 功能： 读取一个字符串* @param limit 读取的长度* @param blankReturn 如果为true ,表示 可以读空字符串。 * 如果为false表示 不能读空字符串。* * 如果输入为空，或者输入大于limit的长度，就会提示重新输入。* @return*/private static String readKeyBoard(int limit, boolean blankReturn) {//定义了字符串String line = "";//scanner.hasNextLine() 判断有没有下一行while (scanner.hasNextLine()) {line = scanner.nextLine();//读取这一行//如果line.length=0, 即用户没有输入任何内容，直接回车if (line.length() == 0) {if (blankReturn) return line;//如果blankReturn=true,可以返回空串else continue; //如果blankReturn=false,不接受空串，必须输入内容}//如果用户输入的内容大于了 limit，就提示重写输入 //如果用户如的内容 >0 <= limit ,我就接受if (line.length() < 1 || line.length() > limit) {System.out.print("输入长度（不能大于" + limit + "）错误，请重新输入：");continue;}break;}return line;} }
JDBCUtilsByDruid
package com.rogue.utils;import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource; import java.io.FileInputStream; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties;/*** 基于druid数据库连接池的工具类*/ public class JDBCUtilsByDruid {private static DataSource ds;//在静态代码块完成 ds初始化static {Properties properties = new Properties();try {properties.load(new FileInputStream("src\\druid.properties"));ds = DruidDataSourceFactory.createDataSource(properties);} catch (Exception e) {e.printStackTrace();}}//编写getConnection方法public static Connection getConnection() throws SQLException {return ds.getConnection();}//关闭连接, 老师再次强调： 在数据库连接池技术中，close 不是真的断掉连接//而是把使用的Connection对象放回连接池public static void close(ResultSet resultSet, Statement statement, Connection connection) {try {if (resultSet != null) {resultSet.close();}if (statement != null) {statement.close();}if (connection != null) {connection.close();}} catch (SQLException e) {throw new RuntimeException(e);}} }
创建user和bill表并定义相应的映射类
user和bill表
-- 添加两个表 -- 账单表 CREATE TABLE bill( billid INT PRIMARY KEY KEY AUTO_INCREMENT, `name`VARCHAR(50) NOT NULL DEFAULT '', `billdate`DATE NOT NULL, modifybanlance DOUBLE NOT NULL DEFAULT 0 )CHARSET=utf8;-- 用户表 CREATE TABLE`user`( `name`VARCHAR(50) PRIMARY KEY NOT NULL DEFAULT '', `banlance`DOUBLE )CHARSET=utf8;Bill
package com.rogue.domain;/** * @Author: Rougue_Y * @Date: 2023/7/9 19:55 **/ public class Bill {private Integer billId;private String name;private String billDate;private Double modifybanlance;public Bill() {}public Bill(Integer billId, String name, String billDate, Double modifybanlance) {this.billId = billId;this.name = name;this.billDate = billDate;this.modifybanlance = modifybanlance;}public Integer getBillId() {return billId;}public void setBillId(Integer billId) {this.billId = billId;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getBillDate() {return billDate;}public void setBillDate(String billDate) {this.billDate = billDate;}public Double getmodifybanlance() {return modifybanlance;}public void setmodifybanlance(Double modifybanlance) {this.modifybanlance = modifybanlance;}@Overridepublic String toString() {return billId+"\t"+name +"\t" + billDate +"\t" + modifybanlance;} }User
package com.rogue.domain;/** * @Author: Rougue_Y * @Date: 2023/7/9 20:41 **/ public class User {private String name;private Double banlance;public User() {}public User(String name, Double banlance) {this.name = name;this.banlance = banlance;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Double getBanlance() {return banlance;}public void setBanlance(Double banlance) {this.banlance = banlance;}@Overridepublic String toString() {return "User{" +"name='" + name + '\'' +", banlance=" + banlance +'}';} }
编写BasicDAO子类BillDAO和UserDAO类
BillDAO
package com.rogue.dao;import com.rogue.domain.Bill;/*** @Author: Rougue_Y* @Date: 2023/7/9 19:58**/ public class BillDAO extends BasicDAO<Bill>{ }UserDAO
package com.rogue.dao;import com.rogue.domain.User;/*** @Author: Rougue_Y* @Date: 2023/7/9 20:43**/ public class UserDAO extends BasicDAO<User> { }
主界面的编写
FFMSView
package com.rogue.view;import com.rogue.domain.Bill; import com.rogue.service.BillService; import com.rogue.service.UserService; import com.rogue.utils.Utility;import java.util.List;/** * @Author: Rougue_Y * @Date: 2023/7/9 19:35 **/ public class FFMSView {private boolean loop=true;private String key = "";private BillService billService = new BillService();private UserService userService = new UserService();public static void main(String[] args) {new FFMSView().mainview();}public void mainview(){while (loop){System.out.println("--------欢迎使用家庭财务管理系统--------");System.out.println("| 1:存入余额 |");System.out.println("| 2:取出余额 |");System.out.println("| 3:增加成员 |");System.out.println("| 4:查询余额 |");System.out.println("| 5:查看账单 |");System.out.println("| 6:退出系统 |");System.out.println("--------------------------------");System.out.println("请选择要进行的业务：");key = Utility.readString(1);switch (key){case "1":System.out.print("请输入存款姓名: ");String name = Utility.readString(50);System.out.print("请输入存入金额：");double money = Double.parseDouble(Utility.readString(10));if (money<=0){System.out.println("金额非法输入");break;}if (userService.modifyBanlance(name,money)){System.out.println("存款成功");}else {System.out.println("用户不存在");}break;case "2":System.out.print("请输入取款姓名: ");name = Utility.readString(50);System.out.print("请输入取出金额：");money = Double.parseDouble("-"+Utility.readString(10));if (money>=0){System.out.println("金额非法输入");break;}if (userService.modifyBanlance(name,money)){System.out.println("取款成功");}else {System.out.println("用户不存在或余额不足");}break;case "3":System.out.print("请输入新增成员姓名: ");name = Utility.readString(50);if (userService.addMenber(name)){System.out.println("添加成功");}else {System.out.println("用户已存在");}break;case "4":System.out.print("请输入查询成员姓名: ");name = Utility.readString(50);System.out.println(userService.queryBanlance(name));break;case "5":System.out.println("1.查询全部账单\t\t2.查询指定成员账单");key = Utility.readString(1);List<Bill> allBill = billService.getAllBill();switch (key){case "1":System.out.println("===========账单===========");for (int i = 0; i < allBill.size(); i++) {System.out.println(allBill.get(i));}break;case "2":System.out.print("请输入存款姓名: ");name = Utility.readString(50);System.out.println("===========账单===========");for (int i = 0; i < allBill.size(); i++) {if (!(allBill.get(i).getName().equals(name))){continue;}System.out.println(allBill.get(i));}break;default:System.out.println("你的输入有误，请重新输入");break;}break;case "6":loop=false;System.out.println("退出系统成功！");break;default:System.out.println("你的输入有误，请重新输入");break;}}} }
UserService类的crud
UserService
package com.rogue.service;import com.rogue.dao.UserDAO; import com.rogue.domain.User;/*** @Author: Rougue_Y* @Date: 2023/7/9 19:35**/ public class UserService {private UserDAO userDAO = new UserDAO();private BillService billService = new BillService();//查看指定成员public User queryMenber(String name) {return userDAO.querySingle("SELECT * FROM user WHERE `name`=?", User.class, name);}//存取款public boolean modifyBanlance(String name, double money) {User user = queryMenber(name);if (user!= null) {if (userDAO.update("UPDATE USER SET banlance=? WHERE NAME=?", user.getBanlance()+money,name) > 0){//添加账单流水billService.addBill(name,money);return true;}}return false;}//增加用户public boolean addMenber(String name) {if (userDAO.querySingle("select * from `user`where name=?",User.class,name)!=null){return false;}return userDAO.update("insert into `user`value(?,0)",name)>0;}//查询余额public double queryBanlance(String name){return Double.parseDouble(userDAO.queryScalar("select banlance from `user` where name=?",name).toString());}}
BillService类的crud
BillService
package com.rogue.service;import com.rogue.dao.BillDAO; import com.rogue.domain.Bill;import java.util.List;/** * @Author: Rougue_Y * @Date: 2023/7/9 19:01 **/ public class BillService {private BillDAO billDAO = new BillDAO();//增加账单流水public void addBill(String name, double money) {billDAO.update("insert into `bill` value(null,?,now(),?)",name,money);}//查看全部账单public List<Bill> getAllBill(){List<Bill> bills = billDAO.queryMulti("select * from `bill`", Bill.class);System.out.println(bills.get(1).getmodifybanlance());return bills;} }
结言
不关注下列三个注意事项是运行不了的：
druid.properties中以下3个括号备注是需要自行修改的
url=jdbc:mysql://localhost:3306/test02（数据库名）?rewriteBatchedStatements=true
username=root(连接数据库账号名)
password=lmt(相应密码)需要添加3个jar包以下是执行操作图，下载地址：Java入门项目：家庭财务管理系统 https://www.aliyundrive.com/s/ML6cfY9byPs 提取码: xo35
3.作者水平有限，如有谬误之处欢迎指正！编写不易，如有帮助请点赞评论支持，一起学习，感谢！
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