房屋出租项目
工具包
package chapter09.D10房屋出租项目.工具包;
import java.util.*;
public class Utility {
//静态属性。。。
private static Scanner scanner = new Scanner(System.in);
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;
}
public static char readChar() {
String str = readKeyBoard(1, false);//就是一个字符
return str.charAt(0);
}
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);
}
public static int readInt() {
int n;
for (; ; ) {
String str = readKeyBoard(10, false);//一个整数，长度<=10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;
}
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;
}
public static String readString(int limit) {
return readKeyBoard(limit, false);
}
public static String readString(int limit, String defaultValue) {
String str = readKeyBoard(limit, true);
return str.equals("")? defaultValue : str;
}
public static char readConfirmSelection() {
System.out.println("请输入你的选择(Y/N): 请小心选择");
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=>N
String 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;
}
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;
}
}
显示界面
package chapter09.D10房屋出租项目.显示界面;
import chapter09.D10房屋出租项目.业务处理.HouseService;
import chapter09.D10房屋出租项目.工具包.Utility;
import chapter09.D10房屋出租项目.数据库.House;
public class HouseView {
boolean flag = true;
HouseService houseService = new HouseService();//调用业务层方法
public void view(int n){
houseService.setnums(n);
do {
System.out.println("---------房屋出租系统--------");
System.out.println("tt1 新增房源");
System.out.println("tt2 查找房源");
System.out.println("tt3 删除房源");
System.out.println("tt4 修改房源");
System.out.println("tt5 房源列表");
System.out.println("tt6 退出");
System.out.println("请输入（1-6）：");
int s= Utility.readInt();
switch (s){
case 1:
System.out.println("新增房源");
addhouse();
break;
case 2:
System.out.println("查找房源");
searchhouse();
break;
case 3:
System.out.println("删除房源");
deletehouse();
break;
case 4:
System.out.println("修改房源");
changehouse();
break;
case 5:
System.out.println("房源列表");
System.out.println("编号t房东姓名t房东电话t地址t租金t状态");
hoselist();
break;
case 6:
exit();
break;
default:
System.out.println("输入有误");
break;
}
}while (flag);
}
public void hoselist(){
House []hs= houseService.list();
for (int i = 0; i
数据库
package chapter09.D10房屋出租项目.数据库;
public class House {
private int ID;
private String name;
private int tel;
private String address;
private int rent;
private String state;
public House(String name, int tel, String address, int rent, String state) {
this.name = name;
this.tel = tel;
this.address = address;
this.rent = rent;
this.state = state;
}
public int getID() {
return ID;
}
public void setID(int ID) {
this.ID = ID;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getTel() {
return tel;
}
public void setTel(int tel) {
this.tel = tel;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public int getRent() {
return rent;
}
public void setRent(int rent) {
this.rent = rent;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
@Override
public String toString() {
return ID +"t"+ name +"t"+ tel +"t"+ address +"t"+ rent +"t" + state ;
}
}
业务处理
package chapter09.D10房屋出租项目.业务处理;
import chapter09.D10房屋出租项目.工具包.Utility;
import chapter09.D10房屋出租项目.数据库.House;
public class HouseService {
private House []houses;//放外面，方法都能调用到
public int housenums=0;
public void add(House h){
if (housenums==houses.length){
System.out.println("超出最大限制，添加失败!");
}else {
houses[housenums]=h;
houses[housenums].setID(housenums+1);//自动生成编号
housenums++;
System.out.println("添加成功!");
}
}
public void delete(int d){
int index=-1;
for (int i = 0; i
调用主类
package chapter09.D10房屋出租项目;
import chapter09.D10房屋出租项目.工具包.Utility;
import chapter09.D10房屋出租项目.显示界面.HouseView;
public class HouseRentApp {
public static void main(String[] args) {
new HouseView().view(4);
}
}
类变量和类方法
package chapter10.D1类变量和类方法;
//static（静态变量）类变量是同一个类所有对象共享的，类变量在类加载的时候就生成了
public class ChildGame {
public static void main(String[] args) {
Child c1 = new Child("xx");
c1.join();
Child.count++;//类变量在类加载的时候就生成，所以没有创建对象就可以调用
//c1.conut++;
Child c2 = new Child("yy");
c2.join();
c2.count++;
Child c3 = new Child("zz");
c3.join();
Child.count++;
System.out.println(Child.count);//等同c1.count
System.out.println(c2.count);//等同c1.count
}
}
class Child{
private String name;
public static int count=0;//类变量遵守修饰符访问权限
public static int h;
public Child(String name){
this.name=name;
}
public void join(){
System.out.println(name+"加入了游戏...");
}
}
package chapter10.D1类变量和类方法;
public class StaticMethod {
public static void main(String[] args) {
Stu xx = new Stu("xx");
Stu yy = new Stu("yy");
xx.payFee(200);
yy.payFee(100);
Stu.showFee();
}
}
class Stu{
private String name;
private static double fee=0;
public int n=10;
public Stu(String name) {
this.name = name;
}
public void payFee(double fee){
Stu.fee+=fee;
}
public static void showFee(){//类方法随类的加载而加载，无this参数，普通方法隐含this参数
System.out.println(Stu.fee);
//System.out.println(n);//静态方法只能调静态属性和方法，普通方法不管静态不静态全可调用
}
}
