Java打印任意一年的日历

打印一年的年历：编写程序提示用户从键盘上输入一个年份（如2021）和该年第一天是星期几，星期用数字表示，0表示星期日，如图：

代码如下：
用ans变量存储个数，如果等于7就换行
第一天把ans=day,然后循环day次打印空格，对齐
import java.util.Scanner;

public class calendar {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println(“输入年份：(e.g.2021):”);
int year = input.nextInt();//year代表哪一年
System.out.println(“输入当年第一天的星期：(0 星期日):”);
int day = input.nextInt();//day代表星期几
int i = 0;
for (i = 0; i < 12; i++) { //循环12个月
switch (i) {
case 0 -> {
System.out.println(" January " + year);
System.out.println("----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 1 -> {//讨论是否为闰年
if (year / 4 == 0 && year / 100 != 0 || year / 400 == 0 && year / 100 != 0) {
System.out.println(” February " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 29; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
else {
System.out.println(” February " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 28; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
}
case 2 -> {
System.out.println(” March " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 3 -> {
System.out.println(” April " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 30; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 4 -> {
System.out.println(” May " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 5 -> {
System.out.println(” June " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 30; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 6 -> {
System.out.println(” July " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 7 -> {
System.out.println(” August " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 8 -> {
System.out.println(” September " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 30; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 9 -> {
System.out.println(” October " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 10 -> {
System.out.println(” November " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 30; j++) {
if (j < 10)
System.out.print(” " + j + " “);
else System.out.print(j + " “);
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
case 11 -> {
System.out.println(” December " + year);
System.out.println(”----------------------------------");
System.out.println(“Sun Mon Tue Wed Thu Fri Sat”);
int ans = day;
for (int k = 0; k < day; k++) {
System.out.print(" “);
}
for (int j = 1; j <= 31; j++) {
if (j < 10)
System.out.print(” " + j + " ");
else System.out.print(j + " ");
ans++;
if (ans == 7) {
System.out.println();
ans = 0;
}
day = ans;
}
System.out.println();
}
}
}
}
}