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dichgrem
2025-11-15 13:30:17 +08:00
parent c20e8949a5
commit 41e6b71bd7
33 changed files with 549 additions and 543 deletions
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1
.gitignore vendored Normal file
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com/study/test/

6
com/study/demo/Demo.java
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@@ -1,7 +1,7 @@
package com.study.demo; package com.study.demo;
public class Demo { public class Demo {
public static void main(String [] args) { public static void main(String[] args) {
System.out.println("HelloWorld!"); System.out.println("HelloWorld!");
} }
} }

18
com/study/demo/test1_1.java
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@@ -1,13 +1,15 @@
package com.study.demo; package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
// I am 212306206 // I am 212306206
public class test1_type { public class test1_type {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner (System.in); Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt(); int a = scanner.nextInt();
int b = scanner.nextInt(); int b = scanner.nextInt();
int sum = a + b; int sum = a + b;
System.out.println(a + " + " + b + " = " + sum); System.out.println(a + " + " + b + " = " + sum);
scanner.close(); scanner.close();
} }
} }

21
com/study/demo/test1_2.java
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@@ -1,16 +1,15 @@
package com.study.demo; package com.study.demo;
public class test2_for { public class test2_for {
public static void main(String[] args) { public static void main(String[] args) {
int[] numbers = new int[5]; int[] numbers = new int[5];
for (int i = 0; i < numbers.length; i++) { for (int i = 0; i < numbers.length; i++) {
numbers[i] = i * 10; numbers[i] = i * 10;
}
System.out.print("数组内容: ");
for (int i = 0; i < numbers.length; i++) {
System.out.print(numbers[i] + " ");
}
} }
}
System.out.print("数组内容: ");
for (int i = 0; i < numbers.length; i++) {
System.out.print(numbers[i] + " ");
}
}
}

25
com/study/demo/test1_3.java
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@@ -1,19 +1,18 @@
package com.study.demo; package com.study.demo;
public class test3_1_99 { public class test3_1_99 {
public static void main(String[] args) { public static void main(String[] args) {
int[] numbers = new int[99]; int[] numbers = new int[99];
for (int i = 0; i < numbers.length; i++) { for (int i = 0; i < numbers.length; i++) {
numbers[i] = i + 1; numbers[i] = i + 1;
}
int sum = 0;
for (int i = 0; i < numbers.length; i++) {
sum += numbers[i];
}
System.out.println("1+2+...+99 的和 = " + sum);
} }
}
int sum = 0;
for (int i = 0; i < numbers.length; i++) {
sum += numbers[i];
}
System.out.println("1+2+...+99 的和 = " + sum);
}
}

19
com/study/demo/test2_2.java
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@@ -1,14 +1,15 @@
package com.study.demo; package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test5 { public class test5 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt(); int a = scanner.nextInt();
int b = scanner.nextInt(); int b = scanner.nextInt();
int c = scanner.nextInt(); int c = scanner.nextInt();
double pi = 3.1415926535; double pi = 3.1415926535;
double area = a * b * c + a * c + (pi * c * c) / 4; double area = a * b * c + a * c + (pi * c * c) / 4;
System.out.printf("%.3f\n", area / 10000); System.out.printf("%.3f\n", area / 10000);
} }
} }

12
com/study/demo/test2_3.java
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@@ -3,10 +3,10 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test6 { public class test6 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int result = 1 << n; int result = 1 << n;
System.out.println(result); System.out.println(result);
} }
} }

16
com/study/demo/test2_4.java
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@@ -3,12 +3,12 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test7 { public class test7 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int x = scanner.nextInt(); int x = scanner.nextInt();
int y = scanner.nextInt(); int y = scanner.nextInt();
int startYear = 2016, startMonth = 8; int startYear = 2016, startMonth = 8;
int totalMonths = (x - startYear) * 12 + y - startMonth + 1; int totalMonths = (x - startYear) * 12 + y - startMonth + 1;
System.out.println(totalMonths); System.out.println(totalMonths);
} }
} }

26
com/study/demo/test2_5.java
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@@ -3,17 +3,17 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test8 { public class test8 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int x = scanner.nextInt(); int x = scanner.nextInt();
int k = scanner.nextInt(); int k = scanner.nextInt();
int a = x / 1000 % k; int a = x / 1000 % k;
int b = x / 100 % 10 % k; int b = x / 100 % 10 % k;
int c = x / 10 % 10 % k; int c = x / 10 % 10 % k;
int d = x % 10 % k; int d = x % 10 % k;
System.out.print(a); System.out.print(a);
System.out.print(b); System.out.print(b);
System.out.print(c); System.out.print(c);
System.out.println(d); System.out.println(d);
} }
} }

30
com/study/demo/test3_1.java
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@@ -3,20 +3,20 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test3_1 { public class test3_1 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int[] arr = new int[n]; int[] arr = new int[n];
for (int i = 0; i < n; i++) { for (int i = 0; i < n; i++) {
arr[i] = scanner.nextInt(); arr[i] = scanner.nextInt();
}
for (int i = 0; i < n / 2; i++) {
int temp = arr[i];
arr[i] = arr[n - 1 - i];
arr[n - 1 - i] = temp;
}
for (int i = 0; i < n; i++) {
System.out.print(arr[i] + (i == n - 1 ? "" : " "));
}
} }
for (int i = 0; i < n / 2; i++) {
int temp = arr[i];
arr[i] = arr[n - 1 - i];
arr[n - 1 - i] = temp;
}
for (int i = 0; i < n; i++) {
System.out.print(arr[i] + (i == n - 1 ? "" : " "));
}
}
} }

32
com/study/demo/test3_2.java
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@@ -3,21 +3,21 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test3_2 { public class test3_2 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int[] a = new int[n]; int[] a = new int[n];
int[] b = new int[n]; int[] b = new int[n];
for (int i = 0; i < n; i++) { for (int i = 0; i < n; i++) {
a[i] = scanner.nextInt(); a[i] = scanner.nextInt();
}
for (int i = 0; i < n; i++) {
b[i] = scanner.nextInt();
}
int sum = 0;
for (int i = 0; i < n; i++) {
sum += a[i] * b[i];
}
System.out.println(sum);
} }
for (int i = 0; i < n; i++) {
b[i] = scanner.nextInt();
}
int sum = 0;
for (int i = 0; i < n; i++) {
sum += a[i] * b[i];
}
System.out.println(sum);
}
} }

36
com/study/demo/test3_3.java
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@@ -3,23 +3,23 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test3_3 { public class test3_3 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int[] arr = new int[n]; int[] arr = new int[n];
for (int i = 0; i < n; i++) { for (int i = 0; i < n; i++) {
arr[i] = scanner.nextInt(); arr[i] = scanner.nextInt();
}
int maxLen = 1, currentLen = 1;
for (int i = 1; i < n; i++) {
if (arr[i] == arr[i - 1]) {
currentLen++;
} else {
maxLen = Math.max(maxLen, currentLen);
currentLen = 1;
}
}
maxLen = Math.max(maxLen, currentLen);
System.out.println(maxLen);
} }
int maxLen = 1, currentLen = 1;
for (int i = 1; i < n; i++) {
if (arr[i] == arr[i - 1]) {
currentLen++;
} else {
maxLen = Math.max(maxLen, currentLen);
currentLen = 1;
}
}
maxLen = Math.max(maxLen, currentLen);
System.out.println(maxLen);
}
} }

32
com/study/demo/test3_4.java
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@@ -3,21 +3,21 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test3_4 { public class test3_4 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int m = scanner.nextInt(); int m = scanner.nextInt();
int[][] image = new int[n][m]; int[][] image = new int[n][m];
for (int i = 0; i < n; i++) { for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) { for (int j = 0; j < m; j++) {
image[i][j] = scanner.nextInt(); image[i][j] = scanner.nextInt();
} }
}
for (int j = 0; j < m; j++) {
for (int i = n - 1; i >= 0; i--) {
System.out.print(image[i][j] + (i == 0 ? "" : " "));
}
System.out.println();
}
} }
for (int j = 0; j < m; j++) {
for (int i = n - 1; i >= 0; i--) {
System.out.print(image[i][j] + (i == 0 ? "" : " "));
}
System.out.println();
}
}
} }

54
com/study/demo/test3_5.java
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@@ -3,32 +3,32 @@ package com.study.demo;
import java.util.Scanner; import java.util.Scanner;
public class test3_5 { public class test3_5 {
public static void main(String[] args) { public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt(); int n = scanner.nextInt();
int[] t = new int[n - 1]; int[] t = new int[n - 1];
int[] s = new int[n]; int[] s = new int[n];
for (int i = 0; i < n - 1; i++) { for (int i = 0; i < n - 1; i++) {
t[i] = scanner.nextInt(); t[i] = scanner.nextInt();
}
for (int i = 0; i < n; i++) {
s[i] = scanner.nextInt();
}
int x = scanner.nextInt();
int y = scanner.nextInt();
int total = 0;
if (x < y) {
for (int i = x - 1; i < y - 1; i++) {
total += s[i] + t[i];
}
total += s[y - 1];
} else {
for (int i = x - 1; i >= y; i--) {
total += s[i] + (i > 0 ? t[i - 1] : 0);
}
total += s[y - 1];
}
System.out.println(total);
} }
for (int i = 0; i < n; i++) {
s[i] = scanner.nextInt();
}
int x = scanner.nextInt();
int y = scanner.nextInt();
int total = 0;
if (x < y) {
for (int i = x - 1; i < y - 1; i++) {
total += s[i] + t[i];
}
total += s[y - 1];
} else {
for (int i = x - 1; i >= y; i--) {
total += s[i] + (i > 0 ? t[i - 1] : 0);
}
total += s[y - 1];
}
System.out.println(total);
}
} }

48
com/study/demo2/Account.java
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@@ -1,36 +1,36 @@
package com.study.demo2; package com.study.demo2;
public class Account { public class Account {
private String accountId; private String accountId;
private String owner; private String owner;
private double balance; private double balance;
public Account(String accountId, String owner, double balance) { public Account(String accountId, String owner, double balance) {
this.accountId = accountId; this.accountId = accountId;
this.owner = owner; this.owner = owner;
this.balance = balance; this.balance = balance;
} }
public void deposit(double amount) { public void deposit(double amount) {
if (amount > 0) { if (amount > 0) {
balance += amount; balance += amount;
}
} }
}
public void withdraw(double amount) { public void withdraw(double amount) {
if (amount > 0 && amount <= balance) { if (amount > 0 && amount <= balance) {
balance -= amount; balance -= amount;
}
} }
}
public void transfer(Account target, double amount) { public void transfer(Account target, double amount) {
if (amount > 0 && amount <= balance) { if (amount > 0 && amount <= balance) {
this.balance -= amount; this.balance -= amount;
target.balance += amount; target.balance += amount;
}
} }
}
public double getBalance() { public double getBalance() {
return balance; return balance;
} }
} }

18
com/study/demo2/Account_Main.java
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@@ -1,15 +1,15 @@
package com.study.demo2; package com.study.demo2;
public class Main { public class Main {
public static void main(String[] args) { public static void main(String[] args) {
Account acc1 = new Account("A001", "张三", 1000); Account acc1 = new Account("A001", "张三", 1000);
Account acc2 = new Account("A002", "李四", 500); Account acc2 = new Account("A002", "李四", 500);
acc1.deposit(200); acc1.deposit(200);
acc1.withdraw(100); acc1.withdraw(100);
acc1.transfer(acc2, 300); acc1.transfer(acc2, 300);
System.out.println("账户1余额:" + acc1.getBalance()); System.out.println("账户1余额:" + acc1.getBalance());
System.out.println("账户2余额:" + acc2.getBalance()); System.out.println("账户2余额:" + acc2.getBalance());
} }
} }

57
com/study/demo2/Animal.java
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@@ -1,44 +1,45 @@
package com.study.demo2; package com.study.demo2;
public abstract class Animal { public abstract class Animal {
protected String name; protected String name;
public Animal(String name) { public Animal(String name) {
this.name = name; this.name = name;
} }
public abstract void makeSound(); public abstract void makeSound();
public abstract void move();
public abstract void move();
} }
class Dog extends Animal { class Dog extends Animal {
public Dog(String name) { public Dog(String name) {
super(name); super(name);
} }
@Override @Override
public void makeSound() { public void makeSound() {
System.out.println(name + " 汪汪叫"); System.out.println(name + " 汪汪叫");
} }
@Override @Override
public void move() { public void move() {
System.out.println(name + " 跑动"); System.out.println(name + " 跑动");
} }
} }
class Bird extends Animal { class Bird extends Animal {
public Bird(String name) { public Bird(String name) {
super(name); super(name);
} }
@Override @Override
public void makeSound() { public void makeSound() {
System.out.println(name + " 叽叽喳喳"); System.out.println(name + " 叽叽喳喳");
} }
@Override @Override
public void move() { public void move() {
System.out.println(name + " 飞翔"); System.out.println(name + " 飞翔");
} }
} }

16
com/study/demo2/Animal_Main.java
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@@ -1,12 +1,12 @@
package com.study.demo2; package com.study.demo2;
public class Main { public class Main {
public static void main(String[] args) { public static void main(String[] args) {
Animal dog = new Dog("Buddy"); Animal dog = new Dog("Buddy");
Animal bird = new Bird("Tweety"); Animal bird = new Bird("Tweety");
dog.makeSound(); dog.makeSound();
dog.move(); dog.move();
bird.makeSound(); bird.makeSound();
bird.move(); bird.move();
} }
} }

51
com/study/demo2/Rectangle.java
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@@ -1,37 +1,38 @@
package com.study.demo2; package com.study.demo2;
public class Rectangle { public class Rectangle {
private double width = 1.0; private double width = 1.0;
private double height = 1.0; private double height = 1.0;
public Rectangle() {} public Rectangle() {
}
public Rectangle(double width, double height) { public Rectangle(double width, double height) {
this.width = width; this.width = width;
this.height = height; this.height = height;
} }
public double getArea() { public double getArea() {
return width * height; return width * height;
} }
public double getPerimeter() { public double getPerimeter() {
return 2 * (width + height); return 2 * (width + height);
} }
public double getWidth() { public double getWidth() {
return width; return width;
} }
public void setWidth(double width) { public void setWidth(double width) {
this.width = width; this.width = width;
} }
public double getHeight() { public double getHeight() {
return height; return height;
} }
public void setHeight(double height) { public void setHeight(double height) {
this.height = height; this.height = height;
} }
} }

24
com/study/demo2/Rectangle_Main.java
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@@ -1,18 +1,18 @@
package com.study.demo2; package com.study.demo2;
public class Main { public class Main {
public static void main(String[] args) { public static void main(String[] args) {
Rectangle rect1 = new Rectangle(5.0, 3.0); Rectangle rect1 = new Rectangle(5.0, 3.0);
System.out.println("面积:" + rect1.getArea()); System.out.println("面积:" + rect1.getArea());
System.out.println("周长:" + rect1.getPerimeter()); System.out.println("周长:" + rect1.getPerimeter());
Rectangle rect2 = new Rectangle(); Rectangle rect2 = new Rectangle();
System.out.println("默认面积:" + rect2.getArea()); System.out.println("默认面积:" + rect2.getArea());
System.out.println("默认周长:" + rect2.getPerimeter()); System.out.println("默认周长:" + rect2.getPerimeter());
rect2.setWidth(2.5); rect2.setWidth(2.5);
rect2.setHeight(4.0); rect2.setHeight(4.0);
System.out.println("修改后面积:" + rect2.getArea()); System.out.println("修改后面积:" + rect2.getArea());
System.out.println("修改后周长:" + rect2.getPerimeter()); System.out.println("修改后周长:" + rect2.getPerimeter());
} }
} }

64
com/study/demo2/Student.java
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@@ -1,40 +1,46 @@
package com.study.demo2; package com.study.demo2;
public class Student { public class Student {
private String id; private String id;
private String name; private String name;
private int[] score = new int[10]; private int[] score = new int[10];
public Student(String id, String name, int[] scores) { public Student(String id, String name, int[] scores) {
this.id = id; this.id = id;
this.name = name; this.name = name;
if (scores.length == 10) { if (scores.length == 10) {
this.score = scores; this.score = scores;
}
} }
}
public double getAverage() { public double getAverage() {
int sum = 0; int sum = 0;
for (int s : score) { for (int s : score) {
sum += s; sum += s;
}
return (double) Math.round((sum / 10.0) * 100) / 100;
} }
return (double) Math.round((sum / 10.0) * 100) / 100;
}
public int getMaxScore() { public int getMaxScore() {
int max = score[0]; int max = score[0];
for (int s : score) { for (int s : score) {
if (s > max) max = s; if (s > max)
} max = s;
return max;
} }
return max;
}
public char getGrade() { public char getGrade() {
double avg = getAverage(); double avg = getAverage();
if (avg >= 90) return 'A'; if (avg >= 90)
else if (avg >= 80) return 'B'; return 'A';
else if (avg >= 70) return 'C'; else if (avg >= 80)
else if (avg >= 60) return 'D'; return 'B';
else return 'E'; else if (avg >= 70)
} return 'C';
else if (avg >= 60)
return 'D';
else
return 'E';
}
} }

15
com/study/demo2/Student_Main.java
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@@ -1,12 +1,11 @@
package com.study.demo2; package com.study.demo2;
public class Main { public class Main {
public static void main(String[] args) { public static void main(String[] args) {
int[] scores = {85, 90, 78, 92, 88, 76, 95, 89, 79, 94}; int[] scores = { 85, 90, 78, 92, 88, 76, 95, 89, 79, 94 };
Student student = new Student("5001", "张三", scores); Student student = new Student("5001", "张三", scores);
System.out.println("平均分: " + student.getAverage());
System.out.println("平均分: " + student.getAverage()); System.out.println("最高分: " + student.getMaxScore());
System.out.println("最高分: " + student.getMaxScore()); System.out.println("等级: " + student.getGrade());
System.out.println("等级: " + student.getGrade()); }
}
} }

9
com/study/demo3/Bicycle.java
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@@ -1,7 +1,8 @@
package com.study.demo3; package com.study.demo3;
public class Bicycle extends Vehicle { public class Bicycle extends Vehicle {
@Override @Override
public void start() { public void start() {
System.out.println("The bike is started"); System.out.println("The bike is started");
} }
} }

104
com/study/demo3/Book.java
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@@ -1,61 +1,57 @@
package com.study.demo3; package com.study.demo3;
public class Book { public class Book {
protected String isbn; protected String isbn;
protected String title; protected String title;
protected boolean available; protected boolean available;
public Book() {
this.available = true;
}
public Book() { public Book(String isbn, String title) {
this.available = true; this.isbn = isbn;
} this.title = title;
this.available = true;
}
public Book(String isbn, String title) {
this.isbn = isbn; public Book(String isbn, String title, boolean available) {
this.title = title; this.isbn = isbn;
this.available = true; this.title = title;
} this.available = available;
}
public Book(String isbn, String title, boolean available) { public String getIsbn() {
this.isbn = isbn; return isbn;
this.title = title; }
this.available = available;
} public void setIsbn(String isbn) {
this.isbn = isbn;
}
public String getIsbn() {
return isbn; public String getTitle() {
} return title;
}
public void setIsbn(String isbn) {
this.isbn = isbn; public void setTitle(String title) {
} this.title = title;
}
public String getTitle() {
return title; public boolean isAvailable() {
} return available;
}
public void setTitle(String title) {
this.title = title; public void setAvailable(boolean available) {
} this.available = available;
}
public boolean isAvailable() {
return available; public void returnBook() {
} if (!this.available) {
this.available = true;
public void setAvailable(boolean available) { System.out.println(
this.available = available; this.title + " (ISBN: " + this.isbn + ") has been returned and is now available.");
} } else {
System.out.println(this.title + " (ISBN: " + this.isbn + ") is already available.");
public void returnBook() {
if (!this.available) {
this.available = true;
System.out.println(this.title + " (ISBN: " + this.isbn + ") has been returned and is now available.");
} else {
System.out.println(this.title + " (ISBN: " + this.isbn + ") is already available.");
}
} }
}
} }

10
com/study/demo3/Car.java
View File

@@ -1,8 +1,8 @@
package com.study.demo3; package com.study.demo3;
public class Car extends Vehicle {
@Override
public void start() { public class Car extends Vehicle {
System.out.println("The car is started"); @Override
} public void start() {
System.out.println("The car is started");
}
} }

49
com/study/demo3/EBook.java
View File

@@ -1,30 +1,35 @@
package com.study.demo3; package com.study.demo3;
public class EBook extends Book { public class EBook extends Book {
private double fileSize; private double fileSize;
public EBook() {
super();
}
public EBook() { public EBook(String isbn, String title, double fileSize) {
super(); super(isbn, title);
} this.fileSize = fileSize;
}
public double getFileSize() {
return fileSize;
}
public void setFileSize(double fileSize) {
this.fileSize = fileSize;
}
public EBook(String isbn, String title, double fileSize) { @Override
super(isbn, title); public String toString() {
this.fileSize = fileSize; return "EBook [ISBN="
} + isbn
+ ", Title="
+ title
public double getFileSize() { + ", FileSize="
return fileSize; + fileSize
} + "MB, Available="
+ available
public void setFileSize(double fileSize) { + "]";
this.fileSize = fileSize; }
}
@Override
public String toString() {
return "EBook [ISBN=" + isbn + ", Title=" + title + ", FileSize=" + fileSize + "MB, Available=" + available + "]";
}
} }

53
com/study/demo3/Library.java
View File

@@ -1,42 +1,37 @@
package com.study.demo3; package com.study.demo3;
import java.util.ArrayList;
import java.util.HashMap; import java.util.HashMap;
import java.util.List; import java.util.List;
import java.util.Map; import java.util.Map;
import java.util.ArrayList;
public class Library { public class Library {
private Map<String, Book> books; private Map<String, Book> books;
public Library() { public Library() {
this.books = new HashMap<>(); this.books = new HashMap<>();
}
public void addBook(Book b) {
String isbn = b.getIsbn();
if (books.containsKey(isbn)) {
System.out.println("The book already exists, adding it failed.");
} else {
books.put(isbn, b);
System.out.println("Book added successfully: " + b.getTitle());
} }
}
public List<Book> searchAvailableBooks() {
List<Book> availableBooks = new ArrayList<>();
for (Book book : books.values()) {
public void addBook(Book b) { if (book.isAvailable()) {
String isbn = b.getIsbn(); availableBooks.add(book);
}
if (books.containsKey(isbn)) {
System.out.println("The book already exists, adding it failed.");
} else {
books.put(isbn, b);
System.out.println("Book added successfully: " + b.getTitle());
}
}
public List<Book> searchAvailableBooks() {
List<Book> availableBooks = new ArrayList<>();
for (Book book : books.values()) {
if (book.isAvailable()) {
availableBooks.add(book);
}
}
return availableBooks;
} }
return availableBooks;
}
} }

55
com/study/demo3/LibraryTest.java
View File

@@ -1,44 +1,39 @@
package com.study.demo3; package com.study.demo3;
import java.util.List; import java.util.List;
public class LibraryTest { public class LibraryTest {
public static void main(String[] args) { public static void main(String[] args) {
Library lib = new Library(); Library lib = new Library();
EBook e1 = new EBook("E001", "Java Basics", 5.2);
EBook e1 = new EBook("E001", "Java Basics", 5.2); e1.setAvailable(false);
e1.setAvailable(false); PrintedBook p1 = new PrintedBook("P001", "Design Patterns", 3);
lib.addBook(e1);
lib.addBook(p1);
PrintedBook p1 = new PrintedBook("P001", "Design Patterns", 3); lib.addBook(p1);
System.out.println("\n--- 可借阅图书列表 (available = true) ---");
List<Book> availableList = lib.searchAvailableBooks();
lib.addBook(e1); if (availableList.isEmpty()) {
lib.addBook(p1); System.out.println("No books are currently available for loan.");
} else {
for (Book book : availableList) {
System.out.println("- " + book.getTitle() + " (ISBN: " + book.getIsbn() + ")");
lib.addBook(p1); }
System.out.println("\n--- 可借阅图书列表 (available = true) ---");
List<Book> availableList = lib.searchAvailableBooks();
if (availableList.isEmpty()) {
System.out.println("No books are currently available for loan.");
} else {
for (Book book : availableList) {
System.out.println("- " + book.getTitle() + " (ISBN: " + book.getIsbn() + ")");
}
}
e1.returnBook();
System.out.println("\n--- 恢复 e1 后可借阅图书列表 ---");
availableList = lib.searchAvailableBooks();
for (Book book : availableList) {
System.out.println("- " + book.getTitle() + " (ISBN: " + book.getIsbn() + ")");
}
} }
e1.returnBook();
System.out.println("\n--- 恢复 e1 后可借阅图书列表 ---");
availableList = lib.searchAvailableBooks();
for (Book book : availableList) {
System.out.println("- " + book.getTitle() + " (ISBN: " + book.getIsbn() + ")");
}
}
} }

44
com/study/demo3/Main3.java
View File

@@ -1,34 +1,30 @@
package com.study.demo3; package com.study.demo3;
public class Main { public class Main {
public static void main(String[] args) { public static void main(String[] args) {
System.out.println("--- 测试 EBook ---"); System.out.println("--- 测试 EBook ---");
EBook ebook = new EBook("123-456", "Java Programming", 2.5); EBook ebook = new EBook("123-456", "Java Programming", 2.5);
System.out.println("EBook Status (Initial): " + ebook.toString()); System.out.println("EBook Status (Initial): " + ebook.toString());
ebook.setAvailable(false);
System.out.println("EBook Status (Borrowed): " + ebook.toString());
ebook.setAvailable(false); ebook.returnBook();
System.out.println("EBook Status (Borrowed): " + ebook.toString()); System.out.println("EBook Status (After Return): " + ebook.toString());
System.out.println("\n--- 测试 PrintedBook ---");
PrintedBook pbook = new PrintedBook();
pbook.setIsbn("789-012");
pbook.setTitle("Python Guide");
pbook.setStock(10);
System.out.println("PBook Status (Initial): " + pbook.toString());
ebook.returnBook(); pbook.setAvailable(false);
System.out.println("EBook Status (After Return): " + ebook.toString()); System.out.println("PBook Status (Borrowed): " + pbook.toString());
pbook.returnBook();
System.out.println("\n--- 测试 PrintedBook ---"); System.out.println("PBook Status (After Return): " + pbook.toString());
PrintedBook pbook = new PrintedBook(); }
pbook.setIsbn("789-012");
pbook.setTitle("Python Guide");
pbook.setStock(10);
System.out.println("PBook Status (Initial): " + pbook.toString());
pbook.setAvailable(false);
System.out.println("PBook Status (Borrowed): " + pbook.toString());
pbook.returnBook();
System.out.println("PBook Status (After Return): " + pbook.toString());
}
} }

48
com/study/demo3/PrintedBook.java
View File

@@ -1,29 +1,35 @@
package com.study.demo3; package com.study.demo3;
public class PrintedBook extends Book { public class PrintedBook extends Book {
private int stock; private int stock;
public PrintedBook() {
super();
}
public PrintedBook() { public PrintedBook(String isbn, String title, int stock) {
super(); super(isbn, title);
} this.stock = stock;
}
public int getStock() {
return stock;
}
public PrintedBook(String isbn, String title, int stock) { public void setStock(int stock) {
super(isbn, title); this.stock = stock;
this.stock = stock; }
}
@Override
public int getStock() { public String toString() {
return stock; return "PrintedBook [ISBN="
} + isbn
+ ", Title="
public void setStock(int stock) { + title
this.stock = stock; + ", Stock="
} + stock
+ ", Available="
@Override + available
public String toString() { + "]";
return "PrintedBook [ISBN=" + isbn + ", Title=" + title + ", Stock=" + stock + ", Available=" + available + "]"; }
}
} }

39
com/study/demo3/StudentManager.java
View File

@@ -1,28 +1,29 @@
package com.study.demo3; package com.study.demo3;
import java.util.*; import java.util.*;
public class StudentManager { public class StudentManager {
public static void main(String[] args) { public static void main(String[] args) {
List<String> studentNames = new ArrayList<>(); List<String> studentNames = new ArrayList<>();
Map<String, Integer> studentScores = new HashMap<>(); Map<String, Integer> studentScores = new HashMap<>();
studentNames.add("张三"); studentNames.add("张三");
studentNames.add("李四"); studentNames.add("李四");
studentNames.add("王五"); studentNames.add("王五");
studentScores.put("张三", 85); studentScores.put("张三", 85);
studentScores.put("李四", 77); studentScores.put("李四", 77);
studentScores.put("王五", 99); studentScores.put("王五", 99);
System.out.println("--- 所有学生姓名 ---"); System.out.println("--- 所有学生姓名 ---");
for (String name : studentNames) { for (String name : studentNames) {
System.out.println(name); System.out.println(name);
}
studentScores.put("张三", 70);
Integer zhangsanScore = studentScores.get("张三");
System.out.println("\n--- 修改后张三的成绩 ---");
System.out.println("张三的成绩: " + zhangsanScore);
} }
studentScores.put("张三", 70);
Integer zhangsanScore = studentScores.get("张三");
System.out.println("\n--- 修改后张三的成绩 ---");
System.out.println("张三的成绩: " + zhangsanScore);
}
} }

9
com/study/demo3/Train.java
View File

@@ -1,7 +1,8 @@
package com.study.demo3; package com.study.demo3;
public class Train extends Vehicle { public class Train extends Vehicle {
@Override @Override
public void start() { public void start() {
System.out.println("The train is started"); System.out.println("The train is started");
} }
} }

27
com/study/demo3/Vehicle.java
View File

@@ -1,20 +1,21 @@
package com.study.demo3; package com.study.demo3;
public class Vehicle { public class Vehicle {
protected String name; protected String name;
public Vehicle(String name) { public Vehicle(String name) {
this.name = name; this.name = name;
} }
public Vehicle() { public Vehicle() {
this.name = "Unknown Vehicle"; this.name = "Unknown Vehicle";
} }
public void start() { public void start() {
System.out.println("Vehicle Start"); System.out.println("Vehicle Start");
} }
public void stop() { public void stop() {
System.out.println("Vehicle Stop"); System.out.println("Vehicle Stop");
} }
} }