1.项目的界面如下

2.说明及思路

本次编程通过idea完成。本人也正在进行java的学习，此文章用来记录这次完成的项目，代码之中颇有不足之处，皆因本人水平所限。

思路：

1.先新建一个包。建立一个主方法，先打印出这个整体的菜单，并通过Switch语句，进行功能选择，输入1-4实现对应的功能。

2.由于选择4是退出，这里整体运用for循环，如果选择退出，则return。

3.1-3中各个功能都需要记录当时的入账或者消费，所以我选择继承，直接创建一个Money父类，然后1继承Money，2继承1,3继承2，这样，创建一个子类对象，能调用各个类的方法，数据都存放在父类中，便于后续遍历输出。

4.对于消费，记录消费项目及金额到数组中，并判断消费金额是否小于余额，否则不能消费，然后记录下当时所剩的金额。收入入账也是这样。

3.代码

1.菜单部分

package LingQianTong;//菜单import java.util.Scanner;public class YeMian {public static void main(String[] args) {Money m = new choose3();Scanner scanner = new Scanner(System.in);for (int i = 1; i > 0; i++) {System.out.println("----------零钱通菜单----------");System.out.println("\t\t1  零钱通明细");System.out.println("\t\t2  消  费");System.out.println("\t\t3  收益入账");System.out.println("\t\t4  退  出");System.out.println("请选择(1-4):");int key = scanner.nextInt();switch (key) {case 1:choose1 m1 = (choose1) m;m1.choose1();break;case 2:choose2 m2 = (choose2) m;m2.choose2();break;case 3:choose3 m3 = (choose3) m;m3.choose3();break;case 4:choose4 m4 = new choose4();if (m4.quit() == 'y') {return;}break;default:System.out.println("请输入1-4");break;}}}
}

2.Money部分

package LingQianTong;//import com.sun.org.apache.xpath.internal.operations.String;public class Money {private double[] arr = {0.0};//记录每次收益入账金额private double nowMoney;//记录当前余额private String[] arr1 = new String[0];//记录消费项目名称private double[] arr2 = {0};//记录每次入账或者消费时，当时的余额//给每个属性设置getset方法public double[] getArr() {return arr;}public void setArr(double[] arr) {this.arr = arr;}public String[] getArr1() {return arr1;}public void setArr1(String[] arr1) {this.arr1 = arr1;}public double getNowMoney() {return nowMoney;}public double setNowMoney(double nowMoney) {//当入账时+，消费时-。实时的余额if (nowMoney < 0) {return this.nowMoney += nowMoney;} else {return this.nowMoney += nowMoney;}}public double[] getArr2() {return arr2;}public void setArr2(double[] arr2) {this.arr2 = arr2;}
}

3.功能1

package LingQianTong;public class choose1 extends Money {//明细public void choose1() {//明细方法System.out.println("----------零钱通明细----------");for (int i = 0, j = 0; i < getArr().length; i++) {//遍历输出入账或者消费的金额，及当时的余额if (i < getArr().length - 1) {if (getArr()[i + 1] > 0) {System.out.println("收益到账\t" + getArr()[i + 1] + "\t余额:" + getArr2()[i + 1]);} else if (getArr()[i + 1] < 0) {System.out.println(getArr1()[j] + "\t" + getArr()[i + 1] + "\t余额:" + getArr2()[i + 1]);j++;}}}}
}

4.功能2

package LingQianTong;//import com.sun.org.apache.xpath.internal.operations.String;import java.util.Scanner;public class choose2 extends choose1 {//消费private String name;//项目名字private double money;//项目金额Scanner scanner = new Scanner(System.in);public void choose2() {//记录消费名字，并存入数组中System.out.println("本次消费项目为:");name = scanner.next();String[] temp = new String[getArr1().length + 1];for (int i = 0; i < getArr1().length; i++) {temp[i] = getArr1()[i];}temp[getArr1().length] = name;setArr1(temp);//传入for (int j = 1; j > 0; j++) {//记录消费金额，并存入数组中，并对消费金额判断，余额能不能支撑此次消费System.out.println("本次消费金额为:");money = scanner.nextDouble();if (money > getNowMoney()) {                    //消费金额>现金时候，不能消费System.out.println("余额不足，支付失败");} else {                                        //能消费时，消费金额存入一个数组中，每消费一次，扩容数组并记录在尾部double[] temp1 = new double[getArr().length + 1];for (int i = 0; i < getArr().length; i++) {temp1[i] = getArr()[i];}temp1[getArr().length] = -money;setArr(temp1);setNowMoney((-money));//更新现金额度j = -100;//结束记录金额过程double[] temp111 = new double[getArr2().length + 1];//记录消费后此时的现金for (int i = 0; i < getArr2().length; i++) {temp111[i] = getArr2()[i];}temp111[getArr2().length] = getNowMoney();setArr2(temp111);}}}
}

5.功能3

package LingQianTong;import java.util.Scanner;public class choose3 extends choose2 {//收益入账private double getMoney;//入账金额Scanner scanner = new Scanner(System.in);public void choose3() {//对入账金额记录并存入数组，金额<=0时，输出输入有误System.out.println("本次到账金额为:");getMoney = scanner.nextDouble();if (getMoney <= 0) {System.out.println("金额输入有误");} else {                    //对入账金额进行记录double[] temp = new double[getArr().length + 1];for (int i = 0; i < getArr().length; i++) {temp[i] = getArr()[i];}setNowMoney(getMoney);temp[temp.length - 1] = getMoney;setArr(temp);double[] temp11 = new double[getArr2().length + 1];for (int i = 0; i < getArr2().length; i++) {temp11[i] = getArr2()[i];}temp11[getArr2().length] = getNowMoney();setArr2(temp11);}}
}

6.功能4

package LingQianTong;import java.util.Scanner;public class choose4 {//退出程序public char quit() {System.out.println("确定退出吗？y/n");Scanner scanner = new Scanner(System.in);char answer = scanner.next().charAt(0);if (answer == 'y') {return 'y';} else {return 'n';}}
}