Java从入门到熟悉的48道练习题[完结]
2024-04-09 12:43:44
July14th.2020 homework
Ps：好久没写blog,所以打算写一个作业练习的系列，可以让新手更容易上手。大家加油！！废话不多说，上代码。
练习1
package july14th;public class Subject1 {public static void main(String[] args) {String []brand={"Nike背包","Adidas运动衫","李宁运动鞋","Kappa外套","361°腰包"};for(int i=0;i<brand.length;i++){System.out.println(brand[i]);}}
}
练习2
package july14th;import java.util.Scanner;public class Subject2 {public static void main(String[] args) {double money[]=new double[5];Scanner sc=new Scanner(System.in);System.out.println("请输入会员本月的消费记录");for(int i=0;i<money.length;i++){System.out.println("请输入第"+(i+1)+"笔购物金额");money[i]=sc.nextDouble(); }System.out.println("");int sum=0;System.out.println("序号 "+"金额(元)");for(int i=0;i<money.length;i++){System.out.println((i+1)+" "+money[i]);sum+=money[i];}System.out.println("总金额 "+sum);}
}
练习3
package july14th;import java.util.Arrays;
import java.util.Scanner;public class Subject3 {public static void main(String[] args) {Scanner scores=new Scanner(System.in);System.out.println("请输入5位学员的成绩（整数）");int[]student=new int[5];for(int i=0;i<student.length;i++){student[i]=scores.nextInt();}Arrays.sort(student);System.out.print("学员成绩按升序排列：");for(int i=0;i<student.length;i++){System.out.print(student[i]+" ");} }
}
练习4
package july14th;import java.util.Arrays;public class Subject4 {public static void main(String[] args) {char[]character={'a','c','u','b','e','p','f','z'};System.out.print("原字符序列：");for(int i=0;i<character.length;i++){System.out.print(character[i]+" ");}System.out.print("
升序排序后：");Arrays.sort(character);for(int i=0;i<character.length;i++){System.out.print(character[i]+" ");}System.out.print("
降序排序后:");for(int i=0 ;i<character.length;i++){for(int j=character.length-1;j>=i+1;j--){if(character[j]>character[j-1]){int temp=character[j-1];character[j-1]=character[j];character[j]=(char) temp;}}}for(int i=0;i<character.length;i++){System.out.print(character[i]+" ");}}
}
练习5
package july14th;import java.util.Scanner;public class Subject5 {public static void main(String[] args) {Scanner sc=new Scanner(System.in);System.out.println("请输入4家店的价格");int price []=new int[4];for(int i=0;i<price.length;i++){ System.out.print("第"+(i+1)+"家店的价格:");price[i]=sc.nextInt(); }int min=price[0];for(int i=0;i<price.length;i++){if(min>price[i]){min=price[i];}}System.out.println("最低价格是"+min);}
}
July20th.2020 homework
睡觉前把下午完成的作业写到blog,好困。。。要是能有个人给我点个赞我将会无比高兴！！
练习6
package july20th;import java.util.Scanner;public class Tourer {String name;int age;String ticket;public void info() {ticket = age <= 12 ? "免费" : "价格为：20元";System.out.println(name + "的年龄为：" + age + ",门票" + ticket+"
");}public static void main(String[] args) {Scanner input = new Scanner(System.in);int age = 0;String name = " ";for (;;) {Tourer person = new Tourer();if (!name.equals("n")) {System.out.print("请输入姓名:");name = input.next();if (name.equals("n")) {System.out.println("退出程序");break;}System.out.print("请输入年龄:");age = input.nextInt();person.name = name;person.age = age;person.info();} else {break;}}}
}
练习7
package july20th;import java.util.Scanner;class Customer{int mark;String cardType;public void showInfo(){ System.out.println("积分："+mark+",卡类型："+cardType);if(mark>1000&&cardType.equals("金卡")||mark>5000&&cardType.equals("普卡")){System.out.println("回馈积分500分！");}}
}public class CustomerTest {public static void main(String[] args) {Scanner input=new Scanner(System.in);Customer test=new Customer();System.out.print("请输入您的信用卡积分：");test.mark=input.nextInt();System.out.print("请输入您的信用卡类型:(金卡/普卡)");test.cardType=input.next();test.showInfo();}
}
练习8
package july20th;import java.util.Scanner;public class Administrator {String name;int passWord;public void adminInfo() {System.out.println("姓名：" + name + ",密码：" + passWord);}public void modifyInfo() {}public static void main(String[] args) {Administrator admin1 = new Administrator();admin1.name = "admin1";admin1.passWord = 111111;admin1.adminInfo();Administrator admin2 = new Administrator();admin2.name = "admin2";admin2.passWord = 222222;admin2.adminInfo();Administrator admin3 = new Administrator();admin3.name = "admin3";admin3.passWord = 333333;Scanner input = new Scanner(System.in);boolean isFlag = true;while (isFlag) {System.out.println("请输入用户名:");String name = input.next();System.out.println("请输入密码:");int passWord = input.nextInt();if (admin3.name.equals("admin3") && admin3.passWord == passWord) {System.out.println("请输入新密码");passWord = input.nextInt();admin3.passWord = passWord;System.out.println("密码修改成功，您的新密码为" + admin3.passWord);isFlag = false;} else {System.out.println("用户名和密码不匹配！您没有权限更新管理员信息。");break;}}}
}
PS:以上只是我自己的解题方法，代码么，其实没有什么标准的死答案，只要写的代码能实现题目要求就好了，活学活用就好了。本菜鸡要去睡觉了Zzz…晚安
July21th.2020 homework
这次的作业除了第一题写的感觉比较完美以外，另外两个题感觉做的不尽如意，不过也算是照题目要求做出来了。。。
练习9
package july21th.pro.demo1;import java.util.Scanner;public class Menu {Scanner input = new Scanner(System.in);public void loginMenu() { // 登录for (;;) {System.out.println("欢迎使用我行我素购物管理系统
");System.out.println(" 1.登陆系统
");System.out.println(" 2.退出
");System.out.println("***************************");System.out.print("请选择,输入数字：");int choose = input.nextInt();if (choose == 1) {mainMenu();break;} else if (choose == 2) {System.out.println("谢谢使用");break;} else {System.out.println("输入错误,请重新输入!");}}}public void mainMenu() { // 主菜单for (;;) {System.out.println("我行我素购物管理系统主菜单
");System.out.println("***************************
");System.out.println(" 1.客户信息管理
");System.out.println(" 2.真情回顾
");System.out.println("***************************");System.out.print("请选择,输入数字或按0返回上一级菜单:");int choose = input.nextInt();if (choose == 1) {customerMenu();break;} else if (choose == 2) {sendCustMenu();break;} else if (choose == 0) {loginMenu();break;} else {System.out.println("输入错误,请重新输入!");}}}public void customerMenu() { // 客戶信息管理for (;;) {System.out.println("我行我素购物管理系统主菜单>客户信息管理");System.out.println("***************************
");System.out.println(" 1.添加客户
");System.out.println(" 2.修改客户
");System.out.println(" 3.删除客户
");System.out.println("***************************");System.out.print("请选择,输入数字或按0返回上一级菜单:");int choose = input.nextInt();if (choose == 1) {for (;;) {System.out.println("执行添加客户");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 2) {for (;;) {System.out.println("执行修改客户");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 3) {for (;;) {System.out.println("执行删除客户");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 0) {mainMenu();break;} else {System.out.println("输入错误,请重新输入!");}}}public void sendCustMenu() { // 回饋顧客for (;;) {System.out.println("我行我素购物管理系统主菜单>");System.out.println("***************************
");System.out.println(" 1.幸运大放送
");System.out.println(" 2.幸运抽奖
");System.out.println(" 3.生日问候
");System.out.println("***************************");System.out.print("请选择,输入数字或按0返回上一级菜单:");int choose = input.nextInt();if (choose == 1) {for (;;) {System.out.println("执行幸运大放送");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 2) {for (;;) {System.out.println("执行幸运抽奖");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 3) {for (;;) {System.out.println("执行生日问候");System.out.print("输入数字0返回上一级菜单:");int choose1 = input.nextInt();if (choose1 == 0) {customerMenu();break;} else {System.out.println("输入错误，输入数字0返回上一级菜单！");}}break;} else if (choose == 0) {mainMenu();} else {System.out.println("输入错误,请重新输入!");}}}}package july21th.pro.demo1;public class MenuTest {public static void main(String[] args) {Menu menu=new Menu();menu.loginMenu();}
}
练习10
人机猜拳（石头剪刀布）
package july21th.pro.demo2;import java.util.Scanner;public class Game {int computer;int self;public int selfGuss() { // 玩家出拳Scanner input = new Scanner(System.in);System.out.println("请您开始出拳:1-石头、2-剪刀、3-布");int self = input.nextInt();for (;;) {if (self == 1) {System.out.println("您选择出拳: 石头");break;} else if (self == 2) {System.out.println("您选择出拳: 剪刀");break;} else if (self == 3) {System.out.println("您选择出拳: 布");break;}}return self;}public int computerGuss() { // 电脑出拳int computer = (int) (Math.random() * 3 + 1);for (;;) {if (computer == 1) {System.out.println("电脑选择出拳: 石头");break;} else if (computer == 2) {System.out.println("电脑选择出拳: 剪刀");break;} else if (computer == 3) {System.out.println("电脑选择出拳: 布");break;}}return computer;}public void compare() { //判断谁赢self = selfGuss();computer = computerGuss();if (computer == 1 && self == 2 || computer == 2 && self == 3|| computer == 3 && self == 1) {System.out.println("电脑赢！！");} else if (computer == self) {System.out.println("平手！！");} else {System.out.println("恭喜，您赢了！");}}
}package july21th.pro.demo2;import java.util.Scanner;public class GameTest {public static void main(String[] args) {Game finGuss=new Game(); Scanner input = new Scanner(System.in);System.out.println("********猜拳游戏********
");System.out.println("请输入您的角色名");String name = input.next();System.out.println("请选择您的对手：1-孙悟空 2-孙悟饭 3-孙悟天");for (;;) {int person = input.nextInt();if (person == 1) {System.out.println("***********"+name+"vs"+"孙悟空"+"***********");break;} else if (person == 2) {System.out.println("***********"+name+"vs"+"孙悟饭"+"***********");break;} else if (person == 3) {System.out.println("***********"+name+"vs"+"孙悟天"+"***********");break;} else {System.out.println("没有此角色，请重新输入!");}}finGuss.compare();}
}
练习11
三个类分别是银行卡 类 ，功能类 ，测试类 。属性 用户名 密码 余额功能 类 登录 显示余额， 存 取关系 功能类中成员变量是银行卡类。
package july21th.pro.demo3;public class BankCard {String name;int passWord;int balance;
}package july21th.pro.demo3;import java.util.Scanner;public class Utility {BankCard card=new BankCard();Scanner input=new Scanner(System.in);public void login(){ //登录System.out.println("******中国建设银行atm******");System.out.println("1.登录");System.out.println("2.退出");System.out.print("请选择");for(;;){int choose=input.nextInt();if(choose==1){money();}else if(choose==2){System.out.println("谢谢使用");break;}else{System.out.println("输入错误，请重新选择！");}}}public void money(){ //主菜单card.name="张三";card.passWord=123456;System.out.println("请输入用户名：");String name=input.next();System.out.println("请输入密码：");int passWord=input.nextInt();if(name.equals("张三")&&card.passWord==passWord){System.out.println("******中国建设银行atm******");System.out.println("1.显示余额");System.out.println("2.开始存钱");System.out.println("3.开始取钱");System.out.println("请选择");for(;;){int choose=input.nextInt();if(choose==1){card.balance=2000;System.out.println("余额为："+card.balance);return;}else if(choose==2){addMoney();return;}else if(choose==3){subMoney();return;}else if(choose==0){System.out.println("按0返回上级菜单");login();}else{System.out.println("选择错误，请重新输入");}}}else{System.out.println("用户名或者密码错误！！");}}public int addMoney(){ //存钱System.out.println("请输入存入的钱数：");int money=input.nextInt();System.out.println("您存入的钱为："+money);return money;}public int subMoney(){System.out.println("请输入要取的钱数：");int money=input.nextInt();System.out.println("您要取的钱为："+money);return money;}
}package july21th.pro.demo3;public class BankCardTest {public static void main(String[] args) {Utility uti=new Utility();uti.login();}
}
不知道什么时候才能恢复线下课啊，该死的新冠，2020，我可太难了啊！！
July24th.2020 homework
这次作业感觉完成的比较满意，虽然完成慢一点。。
练习12
自定义方法 ：两个 int参数 ， 返回 随机数int。
package july24th.demo1;import java.util.Scanner;public class RandomTest {public static void main(String[] args) {Random num = new Random();Scanner input = new Scanner(System.in);System.out.println("请输入第一个整数：");int a = input.nextInt();System.out.println("请输入第二个整数：");int b = input.nextInt();System.out.println(num.getRandom(a, b));}
}class Random {public int getRandom(int a, int b) {int ran = (int) (Math.random() * (b - a + 1) + a);return ran;}
}
任意两个整数之间的随机数：
(int)(Math.random()*(b-a+1)+a;
练习13
自定义方法 ，两个参数1 String[] 2String name 返回 找到的下标。
package july24th.demo2;public class NameIndex {public int getindex(String[] arr, String name) {for (int i = 0; i < arr.length; i++) {if (name.equals(arr[i])) {return i;} }return -1;}
}package july24th.demo2;import java.util.Scanner;public class NameIndexTest {public static void main(String[] args) {Scanner input = new Scanner(System.in);NameIndex index = new NameIndex();String[] name = new String[] { "Jack", "Lilly", "Tom", "Benz" };for (String i : name) {System.out.print(i + " ");}System.out.println("
");System.out.println("请输入你要查找的名字");String person = input.next();int index1 = index.getindex(name, person);if (index1 >= 0) {System.out.println("恭喜您，找到了，在第" + (index1 + 1) + "位");} else {System.out.println("很遗憾，数据库没有这个人！");}}
}
练习14
ATM系统,登录，显示余额、存钱、取钱、退出功能。
package july24th.demo3;public class Bank {int account;int passWord;double balance;
}package july24th.demo3;import java.util.Scanner;public class ATM {Scanner input = new Scanner(System.in);Bank b = new Bank();public void info() { // 初始化b.account = 888888;b.passWord = 123456;b.balance = 500;}public void main() {System.out.println("1.显示余额");System.out.println("2.我要存钱");System.out.println("3.我要取钱");System.out.println("4.退出");for (;;) {System.out.println("请选择功能：");int choose = input.nextInt();if (choose == 1) {showMoney();} else if (choose == 2) {System.out.println("请输入要存入的钱");deposit(input.nextDouble());} else if (choose == 3) {System.out.println("请输入要取出的钱");withdraw(input.nextDouble());} else if (choose == 4) {System.out.println("谢谢使用");break;} else {System.out.println("没有此选项，请重新输入!");}}}public boolean login(int acc, int pass) { // 校验账户密码if (acc == b.account && pass == b.passWord) {return true;}return false;}public void showMoney() { // 账户余额System.out.println("您的余额为" + b.balance);}public void deposit(double amount) { // 存钱if (b.balance > 0) {b.balance += amount;}System.out.println("存钱成功，您当前余额为" + b.balance);}public void withdraw(double amount) { // 取钱if (b.balance < amount) {System.out.println("对不起，您的余额不足！");} else {b.balance -= amount;System.out.println("取钱成功，您当前余额为" + b.balance);}}}package july24th.demo3;import java.util.Scanner;public class ATMTest {public static void main(String[] args) {System.out.println("**********中国建设银行**********");Scanner input = new Scanner(System.in);ATM a = new ATM();a.info();for (int i = 4; i > 0; i--) {System.out.println("请输入账号");int account = input.nextInt();System.out.println("请输入密码");int passWord = input.nextInt();boolean num = a.login(account, passWord);if (num) {System.out.println("登录成功");a.main();break;} else {System.out.println("账号或密码错误" + "您还有" + (i - 1) + "次机会");}}}
}
练习15
自定义数组 ，参数 1 数组 2 字符串 返回数组 int
参数1 无序数组 ， 根据参数2 ，方法中 判断 返回升序或降序后的数组
package july24th.demo4;import java.util.Scanner;public class BubbleTest {public static void main(String[] args) {Bubble test = new Bubble();int[] ron = new int[10];for (int i = 0; i < ron.length; i++) {ron[i] = (int) (Math.random() * 100 + 1);}for (int i : ron) {System.out.print(i + " ");}Scanner input = new Scanner(System.in);System.out.println(" ");for (;;) {System.out.println("请问您是升序还是降序？(up/down)");int[] arr = ron;test.sort(arr, input.next());for (int i : arr) {System.out.print(i + " ");}System.out.println(" ");System.out.println("请问是否继续(Y/N)");String s = input.next();if (s.equals("Y")) {} else {System.out.println("谢谢使用！");break;}}}
}class Bubble {public int[] sort(int[] arr, String choose) {if (choose.equals("up")) {for (int i = 0; i < arr.length - 1; i++) {for (int j = 0; j < arr.length - i - 1; j++) {if (arr[j] > arr[j + 1]) {int temp = arr[j];arr[j] = arr[j + 1];arr[j + 1] = temp;}}}return arr;} else {for (int i = 0; i < arr.length - 1; i++) {for (int j = 0; j < arr.length - i - 1; j++) {if (arr[j] < arr[j + 1]) {int temp = arr[j];arr[j] = arr[j + 1];arr[j + 1] = temp;}}}return arr;}}
}
End.
July27th.2020 homework
练习16
package july27th.demo2;public class Excelle {private String type;private String id;public Excelle(String id,String type){this.id=id;this.type=type;}public String getType() {return type;}public String getId() {return id;}}package july27th.demo2;public class Regal {private String type;private String id;public Regal(String id,String type){this.id=id;this.type=type;}public String getType() {return type;}public String getId() {return id;}}package july27th.demo2;public class Seller {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}public void sell(Excelle car){System.out.println(car.getId()+" "+car.getType());}public void sell(Regal car){System.out.println(car.getId()+" "+car.getType());}public void sell(Excelle car,int num) {System.out.println(name+" "+num+"辆"+"编号："+car.getId()+"品牌："+car.getType());}}package july27th.demo2;public class Test {public static void main(String[] args) {Seller name=new Seller();name.setName("jack");Excelle e=new Excelle("1","凯越");name.sell(e, 100);name.sell(e);}
}
练习17
package july27th.demo1;public class Dog {String nickName;private int health;int love;public Dog(){}public Dog(String nickName, int health, int love) {this.nickName = nickName;this.health = health;this.love = love;}public void setHealth(int health){if(health<=100&&health>=0){this.health=health;}else{this.health=50;}}public int getHealth(){return health;}public void print() {System.out.println("我的名字叫" + nickName + "，健康值是" + health + "，和主人的亲密度是"+ love );}
}package july27th.demo1;public class Penguin {String nickName;private int health;int love;public Penguin(){}public Penguin(String nickName, int health, int love) {this.nickName = nickName;this.health = health;this.love = love;}public void setHealth(int health){if(health<=100&&health>=0){this.health=health;}else{this.health=50;}}public int getHealth(){return health;}public void print() {System.out.println("我的名字叫" + nickName + "，健康值是" + health + "，和主人的亲密度是"+ love );}}package july27th.demo1;import java.util.Scanner;public class PetsTest {public static void main(String[] args) {System.out.println("欢迎来到宠物店");Scanner input=new Scanner(System.in);System.out.print("请输入要领养的宠物名字:");String name=input.next();System.out.println("请选择要领养的宠物类型：(1、狗狗 2、企鹅)");int choose=input.nextInt();if(choose==1){System.out.println("请选择狗狗的品种：(1、聪明的拉布拉多犬 2、酷酷的雪瑞纳)");Dog d=new Dog();int n=input.nextInt();d.setHealth(-50);Dog d2=new Dog(name,d.getHealth(),0);String s=n==1? "聪明的拉布拉多犬":"酷酷的雪瑞纳";System.out.println("宠物的自白：");System.out.println("我的名字叫" + name + "，健康值是" + d2.getHealth() + "，和主人的亲密度是"+ d.love + "，我是一只" + s);}else if(choose==2){System.out.println("请选择企鹅的性别：(1、Q仔2、Q妹)");Penguin d=new Penguin();int f=input.nextInt();d.setHealth(-50);Penguin d2=new Penguin(name,d.getHealth(),0);String s=f==1? "Q仔":"Q妹";System.out.println("宠物的自白：");System.out.println("我的名字叫" + name + "，健康值是" + d2.getHealth() + "，和主人的亲密度是"+ d.love + "，性别是" + s);}else{System.out.println("输入错误，请重新输入");}}
}
End.
July28th.2020 homework
练习18
要求 ：
1 父类水果类 没有属性， 有一个抽象方法 （结出水果,无返回，无参数）
2 香蕉 子类 重写结出水果 输出结出一个香蕉
3 苹果子类 重写结出水果 输出结出一个苹果
4 测试类 new 两个子类 调用结出的方法
package july28th.demo1;public abstract class Fruit {public abstract void fruit();}class Banana extends Fruit{@Overridepublic void fruit() {// TODO Auto-generated method stubSystem.out.println("结出一个香蕉");}
}class Apple extends Fruit{@Overridepublic void fruit() {// TODO Auto-generated method stubSystem.out.println("结出一个苹果");}
}package july28th.demo1;public class FruitTest {public static void main(String[] args) {Banana b=new Banana();b.fruit();Apple a=new Apple();a.fruit();}
}
练习19
要求 ：
1 父类披萨类 没有属性， 有一个生成披萨的方法 （生成披萨,String返回，无参数）
2 芝士披萨 子类 重写生成披萨的方法 输出结出一个芝士披萨
3 牛肉披萨 子类 重写生成披萨的方法 输出结出一个牛肉披萨
4 测试类 new 两个子类 调用结出的方法 注意有返回类型
package july28th.demo2;public class Pizza {public String pizza(){String pizza="披萨";System.out.println(pizza);return pizza;}
}class CheesePizza extends Pizza{@Overridepublic String pizza() {// TODO Auto-generated method stubString pizza="芝士披萨";return pizza;}
}class BeefPizza extends Pizza{@Overridepublic String pizza() {// TODO Auto-generated method stubString pizza="牛肉披萨";return pizza;}
}package july28th.demo2;public class PizzaTest {public static void main(String[] args) {CheesePizza cheese=new CheesePizza();System.out.println("做一个"+cheese.pizza());BeefPizza beef=new BeefPizza();System.out.println("做一个"+beef.pizza());}
}
练习20
package july28th.demo3;public abstract class MotoVehicle {int number;String brand;String color;double mileAge;public abstract void calcRent(int days);
}class Car extends MotoVehicle {String type;public Car(int number, String type) {this.number = number;this.type = type;}@Overridepublic void calcRent(int days) {// TODO Auto-generated method stubif (type.equals("别克商务舱GL8")) {System.out.println("租金是：" + days * 600+"元");} else if (type.equals("宝马550i")) {System.out.println("租金是：" + days * 500+"元");} else if (type.equals("别克林荫大道")) {System.out.println("租金是：" + days * 300+"元");} else {System.out.println("本公司无此车！");}}}class Bus extends MotoVehicle {int seatCount;public Bus(int number, int seatCount) {this.number=number;this.seatCount=seatCount;}@Overridepublic void calcRent(int days) {// TODO Auto-generated method stubif(seatCount>=16){System.out.println("租金是："+days*1500+"元");}else{System.out.println("租金是："+days*800+"元");}}
}package july28th.demo3;import java.util.Scanner;public class MotoVehicleTest {public static void main(String[] args) {for(;;){System.out.println(" 拓海租车行
");System.out.println("************************");System.out.println("轿车：别克商务舱GL8(￥600/天)、宝马550i(￥500/天)、" +"别克林荫大道(￥300/天)
");System.out.println("客车：16座以上(￥1500/天)、16座以下(￥800/天)
");Scanner input=new Scanner(System.in);System.out.println("请问您要租什么类型的车？(1.轿车、2.客车)");int choose=input.nextInt();if(choose==1){System.out.println("您要租的是桥车，请输入您要租的车具体型号");String type=input.next();Car c=new Car(666,type); System.out.println("请输入您要租的天数");int num=input.nextInt();System.out.print("您要租的是："+type+" "+"车牌号是"+c.number+" ");c.calcRent(num);break;}else if(choose==2){System.out.println("您要租的是客车，请问您需要多少座位的客车？");int number=input.nextInt();Bus b=new Bus(888,number);System.out.println("请输入您要租的天数");int day=input.nextInt();System.out.print("您要租的是："+number+"座客车"+" "+"车牌号是"+b.number+" ");b.calcRent(day);break;}else{System.out.println("输入错误，请重新输入");}}}
}
End.
July31th.2020 homework
练习21
要求：
1.国家 父类
2.中国 说汉语
3.美国 说英语
4.人类 说话 参数 是多态
package july31th.demo2;public class Nation {public void speak(){System.out.println("地球人会说话！");}
}class China extends Nation{@Overridepublic void speak() {// TODO Auto-generated method stubSystem.out.println("中国人说汉语");}
}class American extends Nation{@Overridepublic void speak() {// TODO Auto-generated method stubSystem.out.println("美国人说英语");}
}class Person{public void speak(Nation s){s.speak();}
}package july31th.demo2;public class NationTest {public static void main(String[] args) {Person p=new Person();China c=new China();American a=new American();p.speak(c);//p.speak(a);}
}
练习22
要求：
1.果树
2.苹果树
3.香蕉树
4.超市 参数 字符串 返回类型多态 相应的水果
package july31th.demo3;public class SuperMarket {public Tree getTree(String s){Tree n=null;if(s.equals("苹果")){n=new AppleTree();}else if(s.equals("香蕉")){n=new BananaTree();}return n;}
}class Tree{public void show(){System.out.println("树木");}
}class AppleTree extends Tree{@Overridepublic void show() {// TODO Auto-generated method stubSystem.out.println("苹果");}
}class BananaTree extends Tree{@Overridepublic void show() {// TODO Auto-generated method stubSystem.out.println("香蕉");}
}package july31th.demo3;public class SuperMarketTest {public static void main(String[] args) {SuperMarket market=new SuperMarket();String s="苹果";Tree n=market.getTree(s);n.show(); }
}
End.
Auguest3rd.2020 homework
练习23
1 汽车父类（属性：汽车名称，车牌；方法：显示所有信息）
2 租金接口 （计算租金方法 返回double 方法名(int day租借天数)）
3 客车类 （自己属性座位数） 继承汽车 实现租金（重写租金方法 方法中座位数_day） 1 day=500 * 座位数
4 货车类 （自己属性载重量） 继承汽车 实现租金（重写租金方法 方法中载重量_day） 1 day=1000* 多少吨
5 测试类 测试两种车
package august3rd.demo1;public class Car {String brand;String num;public void info() {System.out.println("品牌是：" + brand + "车牌是：" + num);}
}package august3rd.demo1;public interface Rental {double getMoney(int day);
}package august3rd.demo1;public class Bus extends Car implements Rental {int seatNum;@Overridepublic double getMoney(int day) {// TODO Auto-generated method stubdouble money=day*500;return money;}}package august3rd.demo1;public class Truckload extends Car implements Rental {int weight;@Overridepublic double getMoney(int day) {// TODO Auto-generated method stubdouble money=day*1000;return money;}
}package august3rd.demo1;import java.util.Scanner;public class Test {public static void main(String[] args) {Scanner input=new Scanner(System.in);Bus test=new Bus();System.out.println("请输入所需客车的座位数");test.seatNum=input.nextInt();System.out.println("请输入租车天数");int num=input.nextInt();System.out.println(test.getMoney(num)+"元");System.out.println("******************");Truckload t=new Truckload();System.out.println("请输入所需货车的载重");t.weight=input.nextInt();System.out.println("请输入租车天数");int day=input.nextInt();System.out.println(t.getMoney(day)+"元");}
}
练习24
package august3rd.demo2;public class HandSet {String brand;String type;public void sendInfo() {System.out.println("可以发短信");}public void call() {System.out.println("可以打电话");}public void info() {System.out.println("手机品牌是：" + brand + "型号是：" + type);}}package august3rd.demo2;public interface PlayWiring {void paly(String content);
}package august3rd.demo2;public interface TakePhoto {void takePhoto();
}package august3rd.demo2;public interface NetWork {void net();
}package august3rd.demo2;public class CommonHandset extends HandSet implements PlayWiring {@Overridepublic void paly(String content) {// TODO Auto-generated method stubSystem.out.println("可以播放" + content);}}package august3rd.demo2;public class SmartPhone extends HandSet implements NetWork, TakePhoto,PlayWiring {@Overridepublic void paly(String content) {System.out.println("可以播放" + content);}@Overridepublic void takePhoto() {// TODO Auto-generated method stubSystem.out.println("可以照像");}@Overridepublic void net() {// TODO Auto-generated method stubSystem.out.println("可以上网");}}package august3rd.demo2;public class Test {public static void main(String[] args) {CommonHandset test=new CommonHandset();System.out.println("功能机");test.brand="Nokia";test.type="5230";test.info();test.paly("音乐");test.sendInfo();test.call();System.out.println("**************************");System.out.println("智能机");SmartPhone smart=new SmartPhone();smart.brand="Apple";smart.type="iphone8 Plus";smart.info();smart.net();smart.paly("视频");smart.takePhoto();smart.sendInfo();smart.call();}}
End.
August4th.2020 homework
练习25
package august4th.demo1;import java.util.InputMismatchException;
import java.util.Scanner;import org.apache.log4j.Logger;class Subject {int firstNum;int secondNum;public void getNum(int num) throws Exception {if (num == 0) {throw new Exception("出现错误，被除数和除数必须是整数，除数不能为零。");}}
}public class SubjectTest {public static Logger log = Logger.getLogger("");public static void main(String[] args) {Scanner input = new Scanner(System.in);Subject test = new Subject();System.out.print("请输入被除数:");test.firstNum = input.nextInt();log.debug("输入被除数:"+test.firstNum);System.out.print("请输入除数:");test.secondNum = input.nextInt();log.debug("输入除数:"+test.secondNum);if(test.secondNum==0){log.error("/ by zero");}try {test.getNum(test.secondNum);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}System.out.println(test.firstNum / test.secondNum);log.debug("输出运算结果："+test.firstNum +"/"+ test.secondNum+"="+(test.firstNum / test.secondNum));}
}
练习26
package august4th.demo2;public class Animal {private String name;private int legNum;public Animal(String name, int legNum) {this.name = name;this.legNum = legNum;}public String getName() {return name;}public int getLegNum() {return legNum;}public void shout() {System.out.println("动物会叫！");}}class Cat extends Animal {public Cat(String name, int legNum) {super(name, legNum);// TODO Auto-generated constructor stub}@Overridepublic void shout() {// TODO Auto-generated method stubSystem.out.println("猫咪喵喵叫!");}}class Duck extends Animal {public Duck(String name, int legNum) {super(name, legNum);// TODO Auto-generated constructor stub}@Overridepublic void shout() {// TODO Auto-generated method stubSystem.out.println("鸭子嘎嘎叫!");}}package august4th.demo2;public class AnimalTest {public static void main(String[] args) {Animal cat=new Cat("coco", 4);System.out.print("昵称："+cat.getName()+"有");System.out.println(cat.getLegNum()+"条腿");cat.shout();System.out.println("**********************");Animal duck=new Duck("二丫",2);System.out.print("昵称："+duck.getName()+"有");System.out.println(duck.getLegNum()+"条腿");duck.shout();}}
练习27
package august4th.demo3;public class Animal {private String name;public Animal(String name) {this.name = name;}public void shout(){System.out.println("动物会叫！");}
}class Cat extends Animal implements Terrestrial {private int legNum;public Cat(String name,int legNum) {super(name);this.legNum=legNum;// TODO Auto-generated constructor stub}@Overridepublic void shout() {// TODO Auto-generated method stubSystem.out.println("猫咪喵喵叫！");}@Overridepublic int getLegNum() {// TODO Auto-generated method stubreturn this.legNum;}}class Duck extends Animal implements Terrestrial{private int legNum;public Duck(String name,int legNum) {super(name);this.legNum=legNum;// TODO Auto-generated constructor stub}@Overridepublic void shout() {// TODO Auto-generated method stubSystem.out.println("鸭子嘎嘎叫");}@Overridepublic int getLegNum() {// TODO Auto-generated method stubreturn this.legNum;}}class Dolphin extends Animal{public Dolphin(String name) {super(name);// TODO Auto-generated constructor stub}@Overridepublic void shout() {// TODO Auto-generated method stubSystem.out.println("海豚音");}
}package august4th.demo3;public interface Terrestrial {int getLegNum();
}package august4th.demo3;public class AnimalTest {public static void main(String[] args) {Cat cat=new Cat("皮卡丘",4);System.out.println(cat.getLegNum());cat.shout();Duck duck=new Duck("唐老鸭", 2);System.out.println(duck.getLegNum());duck.shout();Dolphin d=new Dolphin("TT");d.shout();}
}
End.
August7th.2020 homework
练习28
新建一个List 对象 ，学生类姓名和分数属性 ，新建5个对象，显示所有学生信息。
package august7th;import java.util.ArrayList;
import java.util.List;public class StudentTest {public static void main(String[] args) {List list=new ArrayList();Student stu=new Student("小明",78);Student stu2=new Student("小花",90);Student stu3=new Student("小刚",23);Student stu4=new Student("小东",50);Student stu5=new Student("小花",44);list.add(stu);list.add(stu2);list.add(stu3);list.add(stu4);list.add(stu5);// for(Object o:list){ for each遍历
// Student student=(Student)o;
// student.info();
// }for(int i=0;i<list.size();i++){Student student=(Student) list.get(i);student.info();}}
}class Student{String name;int scores;public Student(String name,int scores){this.name=name;this.scores=scores;}public void info(){System.out.println("姓名："+name+" "+"年龄："+scores);}
}
End
August11th.2020 homework
练习29
第一个类 两个构造方法 无参数和两个参数 set/get
package august11th;import java.util.ArrayList;
import java.util.List;public class PenguinTest {public static void main(String[] args) {List list=new ArrayList();Penguin p1=new Penguin("东东 ，健康度：",98);Penguin p2=new Penguin("南南 ，健康度：",96);Penguin p3=new Penguin("西西 ，健康度：",99);Penguin p4=new Penguin("北北， 健康度：",95);list.add(p1);list.add(p2);list.add(p3);list.add(p4);System.out.println("一共"+list.size()+"只企鹅");for(Object o:list){Penguin p=(Penguin)o;System.out.println(p);}System.out.println("删除第一个企鹅的信息
");list.remove(0);for(Object o:list){Penguin p=(Penguin)o;System.out.println(p);}System.out.println("删除西西的信息
");list.remove(p3);for(Object o:list){Penguin p=(Penguin)o;System.out.println(p);}}
}class Penguin {private String name = "大白";int health = 100;private int love = 0;String sex = "Q仔";public String getName() {return name;}public void setName(String name) {this.name = name;}public int getLove() {return love;}public void setLove(int love) {this.love = love;}public Penguin(String name, int love) {super();this.name = name;this.love = love;}public Penguin() {super();}@Overridepublic String toString() {// TODO Auto-generated method stubreturn name+love;}}
练习30
package august11th;import java.util.HashMap;
import java.util.Map;
import java.util.Set;public class DogTest {public static void main(String[] args) {
// Dog ou=new Dog("欧欧","雪纳瑞");
// Dog ya=new Dog("亚亚","拉布拉多");
// Dog mei=new Dog("美美","柯基");
// Dog fei=new Dog("菲菲","柴犬");Map<String,String> dog=new HashMap<String,String>();dog.put("欧欧","雪纳瑞"); //dog.put(key,value)dog.put("亚亚","拉布拉多");dog.put("美美","柯基");dog.put("菲菲","柴犬");if(dog.containsKey("欧欧")){ //判断是否有key"欧欧"Dog d=new Dog("欧欧","拉布拉多");System.out.println(d.getName()+" "+d.getStrain());}else{Set set=dog.keySet();for(Object o:set){ System.out.println(set);}}}
}class Dog {private String name;private int health;private int love;private String strain;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getHealth() {return health;}public void setHealth(int health) {this.health = health;}public int getLove() {return love;}public void setLove(int love) {this.love = love;}public String getStrain() {return strain;}public void setStrain(String strain) {this.strain = strain;}public Dog(String name, String strain) {super();this.name = name;this.strain = strain;}public Dog(){}}
练习31
package august11th;import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;public class RabbitTest {public static void main(String[] args) {Rabbit r1 = new Rabbit("欧欧", "公");Rabbit r2 = new Rabbit("亚亚", "母");Rabbit r3 = new Rabbit("美美", "公");Rabbit r4 = new Rabbit("菲菲", "母");Map<String, String> rabbit = new HashMap<String, String>();rabbit.put(r1.getName(), r1.getSex()); // dog.put(key,value)rabbit.put(r2.getName(), r2.getSex());rabbit.put(r3.getName(), r3.getSex());rabbit.put(r4.getName(), r4.getSex());for(String n:rabbit.keySet()){System.out.println(n);}System.out.println("*****************");Iterator it = rabbit.keySet().iterator();while (it.hasNext()) {Object s = it.next();System.out.println(s);}}
}class Rabbit {private String name = "大白";int health = 100;private int love = 0;String sex = "公";public String getName() {return name;}public void setName(String name) {this.name = name;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public Rabbit(String name, String sex) {super();this.name = name;this.sex = sex;}public Rabbit() {super();}@Overridepublic String toString() {// TODO Auto-generated method stubreturn name + love;}
}
End
August12th.2020 homework
练习32
package august12th;import java.util.Scanner;public class Subject {public static void main(String[] args) {for (;;) {Scanner input = new Scanner(System.in);System.out.print("请输入用户名:");input.next();System.out.print("请输入密码：");int l = input.nextInt();Way w = new Way();w.getLength(l);Integer it=l;String s=it.toString();if(s.length()==6){break;}}}
}class Way {public void getLength(int l) {Integer it = l;String s = it.toString();s.length();if (s.length() < 6) {System.out.println("密码长度不小于6位！请重新输入！");} else if (s.length() > 6) {System.out.println("密码长度不能大于6位！请重新输入！");} else {System.out.println("注册成功！");}}
}
练习33
package august12th;import java.util.Scanner;public class Subject2 {public static void main(String[] args) {for (;;) {Scanner input = new Scanner(System.in);System.out.print("请输入用户名:");String s = input.next();System.out.print("请输入密码:");int n = input.nextInt();if (s.equalsIgnoreCase("tom")) {System.out.println("用户名正确，登录成功！");break;} else {System.out.println("用户名错误！");}}}
}
练习34
package august12th;import java.util.Scanner;public class Subject3 {public static void main(String[] args) {System.out.println("***欢迎进入注册系统***
");for (;;) {Scanner input = new Scanner(System.in);System.out.print("请输入用户名：");String s = input.next();System.out.print("请输入密码:");int l = input.nextInt();Until t = new Until();t.getLength(s, l);Integer it = l;String n = it.toString();if (s.length() >= 3 && n.length() >= 6) {System.out.print("请再次输入密码：");int j = input.nextInt();t.passWord(l, j);if (l == j) {break;}}}}
}class Until {public void getLength(String s, int l) {Integer it = l;String n = it.toString();if (s.length() < 3 || n.length() < 6) {System.out.println("用户名长度不能小于3，密码长度不能小于6");}}public void passWord(int i, int j) {if (i == j) {System.out.println("注册册成功，请牢记用户名和密码");} else {System.out.println("两次输入的密码不相同，请重新输入！");}}
}
练习35
package august12th;import java.util.Scanner;public class Subject4 {public static void main(String[] args) {for (;;) {Scanner input = new Scanner(System.in);System.out.println("---欢迎进入作业提交系统---");System.out.print("请输入Java文件名：");String s = input.next();System.out.print("请输入邮箱：");String n = input.next();Way2 test = new Way2();test.getInfo(s, n);int n1 = n.indexOf('.');int n2 = n.indexOf('@');if (s.endsWith(".java") && n1 > n2) {break;} else {System.out.println("E-mail无效。
作业提交失败！");}}}
}class Way2 {public void getInfo(String s, String t) {int n1 = t.indexOf('.');int n2 = t.indexOf('@');if (s.endsWith(".java") && n1 > n2) {System.out.println("作业提交成功！");}}
}
练习36
package august12th;public class Subject5 {public static void main(String[] args) {String word="Hello, ";word=word.trim(); //删除前导和尾随空格String s=word.concat("小鱼儿！"); //将指定的字符串连接到该字符串的末尾。int index1=s.indexOf(',');int index2=s.indexOf("!");//返回一个字符串，该字符串是此字符串的子字符串。 子字符串以指定索引处的字符开头，并扩展到该字符串的末尾。 System.out.println(s.substring(0, s.length()));}
}
练习37
package august12th;public class Subject6 {public static void main(String[] args) {System.out.println("***原歌词格式***");System.out.println("长亭外 古道边 芳草碧连天 晚风拂柳笛声残 夕阳山外山");System.out.println("***拆分后词模式***");String s="长亭外 古道边 芳草碧连天 晚风拂柳笛声残 夕阳山外山";/*此方法返回的数组包含此字符串的每个子字符串，该字符串由与给定表达式匹配的另一个子字符串终止，*或由字符串结尾终止。 数组中的子字符串按照它们在此字符串中的顺序排列。 * 如果表达式与输入的任何部分不匹配，则生成的数组只有一个元素，即这个字符串。 */String[]arr=s.split(" ", 5);for(String i:arr){System.out.println(i);}}
}
练习38
package august12th;import java.util.Scanner;public class Subject7 {public static void main(String[] args) {Scanner input=new Scanner(System.in);System.out.println("请输入一串数字");String num=input.next();/*由start和end的参数s的顺序按顺序插入到指定目的地偏移量的该序列中，向上移动原始位于该位置的任何字符。* 该序列的长度增加了end - start 。*/StringBuffer s=new StringBuffer(num);for(int i=s.length()-3;i>0;i=i-3){s.insert(i, ',');}System.out.println(s);}
}
Ps:开始学java高级语法了，渐渐的感觉有些吃力，不过还好，9月1估计能开线下课了，加油吧，这次作业全用循环写了，有时候逻辑做了效果出不来找半天，不过解决了以后会有很大的成功感！
End
August15th.2020 homework
一周没更新了，今天补下作业。
练习39
定义一个方法 参数是字符串 返回int
要求 参数是生日 类型为 1900-1-1 返回 年龄
package august15th;
/*** 输入字符串生日，获取当前年龄* */
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;public class Subject {public static void main(String[] args) throws Exception {Scanner input=new Scanner(System.in);System.out.println("请输入你的生日：(格式XXXX-X-X)");String s=input.next();SimpleDateFormat f=new SimpleDateFormat("yyyy-MM-dd");Date d=f.parse(s);long date=d.getTime();Date time=new Date();long date1=time.getTime();System.out.println((date1-date)/1000/60/60/24/365);}
}
练习40
定义一个方法 参数是1 double 2 int 返回double
要求 参数1 是double 2是整数要求保留的小数点后几位 ，方法中对参数1进行格式化，在转换成double类型返回结果
package august15th;import java.text.DecimalFormat;
import java.util.Scanner;public class Subject2 {public static void main(String[] args) {double dec;Scanner input = new Scanner(System.in);System.out.println("请输入一个保留小数点后5位的数");double n = input.nextDouble();System.out.println("请输入想要保留小数点后几位?(可选1、2、3、4)");int n1 = input.nextInt();switch(n1){case 1:System.out.println(new DecimalFormat("#.#").format(n));break;case 2:System.out.println(new DecimalFormat("#.##").format(n));break;case 3:System.out.println(new DecimalFormat("#.###").format(n));break;case 4:System.out.println(new DecimalFormat("#.####").format(n));}}}
练习41
定义一个方法 参数是File类对象 ，返回字符串
要求 参数的一个文件，方法中 得到 文件的最后一次修改日期，格式化格式为 2020-1-1 11:20:33 把格式化后的字符串 返回
package august15th;import java.io.File;
import java.io.IOException;
import java.text.Format;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;public class Subject3 {public static void main(String[] args) throws IOException {File f=new File("D://a.txt");long time=f.lastModified();Date d=new Date(time);Format SimpleDateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");Calendar cal=Calendar.getInstance();cal.setTimeInMillis(f.lastModified());String time1=SimpleDateFormat.format(cal.getTime());System.out.println(time1);}}
这道题不是很懂，网上找了下类似的参考一下！
练习42
定义一个方法 参数是File类对象 ，返回字符串
要求 参数的一个文件，方法中 得到 文件的大小，要求返回文件的大小 可以自动转换为 byte kb mb gb 返回字符串
package august15th;import java.io.File;public class Subject4 {public static void main(String[] args) {File f=new File("D:/A/a.txt/w.txt");long a=f.length();System.out.println(a);System.out.println((f.length()/1024.0/1024.0));}}
Ps:感觉作页越来越难了，有什么不对的欢迎大家指出来！！
END
August18th.2020 homework
练习43
封装一个方法可以复制文件
返回类型 boolean 复制是否成功
参数源文件，目标目录（这题做的有点问题！！）
package august18th;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;public class Subject {public static void main(String[] args) {File f=null;File o=null;FileOutputStream out=null;FileInputStream in=null;try{f=new File("E:/Java76/Java/io/Test/a.txt");o=new File("E:/Java76/Java/io/java/b.txt");in=new FileInputStream(f);out=new FileOutputStream(o);byte[]b=new byte[1024];for(int count=0;(count=in.read(b))!=-1;){out.write(b,0,count);out.flush();}System.out.println("复制成功");}catch(Exception e){e.printStackTrace();System.out.println("复制失败");}finally{try{in.close();}catch(IOException e){e.printStackTrace();}} try{out.close();}catch(IOException e){e.printStackTrace();}}
}
练习44
封装一个方法 可以把指定的内容输出到指定的目录文件
返回类型 boolean
参数（内容，目标文件）
package august18th;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;public class Subject2 {public static void main(String[] args) throws Exception {File f=new File("E:"+File.separator+"java76/a.txt"); //目标文件输入流InputStream is=new FileInputStream(f);byte[]c=new byte[1024];//String s=" asdf";
// for(int count=0;(count=is.read(c))!=-1;){
// s+=new String(c,0,count);
// }
// System.out.println(s);is.close();File f1=new File("E:"+File.separator+"java76/a.txt"); //目标文件输出流OutputStream out=new FileOutputStream(f1,true);String t="你好";out.write(t.getBytes());out.write(t.getBytes());out.close();}}
练习45
封装一个方法 读取一个文本文件
返回类型 Sting 读取的文件内容
参数（源文件）
package august18th;import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Reader;
import java.io.Writer;public class Subject3 {public static void main(String[] args) throws Exception { //字符输入输出流读写！File f=new File("D:"+File.separator+"a.txt");Reader read=new FileReader(f);char[]c=new char[3];String s=" ";for(int count=0;(count=read.read(c))!=-1;){s+=new String(c,0,count);}System.out.println(s);File f1=new File("D:"+File.separator+"a.txt");Writer w=new FileWriter(f1);w.write("大保健");w.flush();w.close();}}
PS:今天是我27岁生日，没有惊喜，没有意外，只有老爸晚上给我发了个生日红包，果然还是只有家人最关心自己，加油吧，定了场livehouse的票，第一次去看，真的很喜欢Hip-hop，加油吧，心态放端正就好！！
End
August19th.2020 homework
练习46
使用 BufferedReader 读取一个.txt 文件的内容
package august19th;import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.Reader;public class Subject {public static void main(String[] args) throws Exception {File f=new File("a.txt");//字符输入流Reader r=new FileReader(f);BufferedReader br=new BufferedReader(r,1024*1024);
// String s=br.readLine();
// System.out.println(s);
// String s1=br.readLine();
// System.out.println(s1);String s=" ";for(String sline=" ";(sline=br.readLine())!=null;){s+= sline+"
";}System.out.println(s);r.close();br.close();}
}
练习47
ObjectInputStream， ObjectOutputStream ，实现对象的序列号和反序列化习47
package august19th;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;public class Subject3 {public static void main(String[] args) throws Exception {
// Users u = new Users(1, "333");File f = new File("a.txt");
// 序列话操作
// OutputStream w = new FileOutputStream(f);
// ObjectOutputStream out = new ObjectOutputStream(w);// out.writeObject(u);
// out.flush();//反序列化操作InputStream o=new FileInputStream(f);ObjectInputStream in=new ObjectInputStream(o);Users u=(Users)in.readObject();System.out.println(u.getAge()+" "+u.getName());}}class Users implements Serializable {private int age;private String name;public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Users() {super();}public Users(int age, String name) {super();this.age = age;this.name = name;}}
练习48
使用继承和实现接口的两种方法，开启子线程复制 一个文件
package august19th;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;public class Subject2 extends Thread {public void run() {File f=null;File o=null;FileOutputStream out=null;FileInputStream in=null;try{f=new File("E:/Java76/Java/io/Test/a.txt");o=new File("E:/Java76/Java/io/java/b.txt");in=new FileInputStream(f);out=new FileOutputStream(o);byte[]b=new byte[1024];for(int count=0;(count=in.read(b))!=-1;){out.write(b,0,count);out.flush();}System.out.println("复制成功");}catch(Exception e){e.printStackTrace();System.out.println("复制失败");}finally{try{in.close();}catch(IOException e){e.printStackTrace();}} try{out.close();}catch(IOException e){e.printStackTrace();}}public static void main(String[] args) {Thread test=new Thread(new Subject2());test.start();}
}class Sub implements Runnable{@Overridepublic void run() {// TODO Auto-generated method stubFile f=null;File o=null;FileOutputStream out=null;FileInputStream in=null;try{f=new File("E:/Java76/Java/io/Test/a.txt");o=new File("E:/Java76/Java/io/java/b.txt");in=new FileInputStream(f);out=new FileOutputStream(o);byte[]b=new byte[1024];for(int count=0;(count=in.read(b))!=-1;){out.write(b,0,count);out.flush();}System.out.println("复制成功");}catch(Exception e){e.printStackTrace();System.out.println("复制失败");}finally{try{in.close();}catch(IOException e){e.printStackTrace();}} try{out.close();}catch(IOException e){e.printStackTrace();}}}
此系列完结，后续我会更新进阶版的编程题，大家一起进步！
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