Java编程学习的几个典型实例详解

import java.util.Scanner;public class HotelDemo { //写在类里面，则每个方法都可以访问到，避免了参数传递的繁琐； static int h=5,w=10; static String[][] rooms=new String[5][10]; public static void main(String[] args) {  @SuppressWarnings("resource")  Scanner s=new Scanner(System.in);  while(true){   System.out.println("请输入 in,out,search,quit:");   String temp=s.next();   int room=0;   if("in".equals(temp)){//防止出现空指针异常；    System.out.println("输入房间号：");    room=s.nextInt();    System.out.println("输入名字：");    String name=s.next();    if(in(room,name)) System.out.println("入住完成！");    System.out.println("room"+room+"name"+name);   }else if("out".equals(temp)){    System.out.println("输入房间号：");    room=s.nextInt();    if(out(room)) System.out.println("退房完成！");    System.out.println("out"+room);   }else if("search".equals(temp)){    System.out.println("输入房间号（-1代表全部）：");    room=s.nextInt();    search(room);   }else if("quit".equals(temp)||"exit".equals(temp)){    break;   }else{    System.out.println("命令错误！");   }  } } private static boolean search(int room) {  if(room==-1){   //打印所有的信息；   for(int i=0;i<h;i++){    for(int j=0;j<w;j++){     int room2=(i+1)*100+j+1;     System.out.print(room2+"/t");    }    System.out.println();    for(int k=0;k<w;k++){     System.out.print(rooms[i][k]==null?"empty":rooms[i][k]);     System.out.print("/t");    }    System.out.println();    System.out.println();   }   return true;     }else{   int r=room/100-1;   int c=room%100-1;   if(r<0||r>=h||c<0||c>=w){    System.out.println("房间号错误！");    return false;   }   System.out.println(rooms[r][c]==null?"empty":rooms[r][c]);   return true;  } } private static boolean out(int room) {  int r=room/100-1;  int c=room%100-1;  if(r<0||r>=h||c<0||c>=w){   System.out.println("房间号错误！");   return false;  }  if(rooms[r][c]==null||"".equals(rooms[r][c])){//   System.out.println("此房间没有人！");   return false;  }  rooms[r][c]=null;  return true; } private static boolean in(int room, String name) {  int r=room/100-1;  int c=room%100-1;  if(r<0||r>=h||c<0||c>=w){   System.out.println("房间号错误！");   return false;  }  if(rooms[r][c]!=null){//   System.out.println("此房间已经有人！");   return false;  }  rooms[r][c]=name;  return true; }}

import java.util.Scanner; public class SpiralSquare01{  public static void main(String[] args) {  @SuppressWarnings("resource")  Scanner s=new Scanner(System.in);  System.out.println("请输入螺旋方阵的长");  int indexY=s.nextInt();  System.out.println("请输入螺旋方阵的宽");  int indexX=s.nextInt();  if(indexX<=0||indexY<=0){   System.out.println("输入的数字不合法！");   return;  }  int[][] square=new int[indexX][indexY];  int x=0;  int y=0;  for(int i=1;i<=indexX*indexY;){   while(y<square[x].length-1&&square[x][y+1]==0){    square[x][y++]=i++;   }   while(x<square.length&&square[x][y]==0){    square[x++][y]=i++;   }   while(y>0&&square[x-1][y-1]==0){    square[x-1][--y]=i++;   }   --x;   while(x>1&&square[x-1][y]==0){    square[--x][y]=i++;   }   y++;  }  for(int i=0;i<square.length;i++){   for(int j=0;j<square[i].length;j++){    System.out.print(square[i][j]+"/t");   }   System.out.println();  } }}

public class TestBrick { public static void main(String[] args) {  int manNum=0;  int womanNum=0;  for(int i=0;i<=9;i++){   for(int j=0;j<12;j++){      if(((i*4+j*3+(36-i-j)/2)==36)&&((36-i-j)%2==0)){     //注意：孩子的人数必须是偶数，否则会出现一个孩子一次也没有搬的情况，不符合题意     manNum=i;     womanNum=j;     System.out.println("男的的人数是"+manNum);     System.out.println("女的的人数是"+womanNum);     System.out.println("孩子的人数是"+(36-manNum-womanNum));    }   }  }  } }

import java.util.Scanner; public class TestTime {  /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub  @SuppressWarnings("resource")  Scanner s=new Scanner(System.in);  System.out.println("请输入秒数：");  int second =s.nextInt();  int hour=second/3600;  int minite=second%3600/60;  int sec=second%60;   System.out.println("转换后为："+hour+"小时"+minite+"分"+sec+"秒");    } }

//密码的自动生成器：密码由大写字母/小写字母/数字组成，生成六位随机密码;import java.util.Random; public class TestPassword {  /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub    char[] pardStore=new char[62];     //把所有的大写字母放进去     for(int i=0;i<20;i++){      pardStore[i]=(char)('A'+i);     }     //把所有的小写字母放进去     for(int i=26;i<52;i++){      pardStore[i]=(char)('a'+i);     }          //吧0到9放进去     for(int i=52;i<62;i++){      pardStore[i]=(char)('0'+(i-52));     }          //生成6位随机密码     Random r=new Random();     for(int i=0;i<6;i++){      int n=r.nextInt(62);      System.out.print(pardStore[n]);     }    } }

import java.util.Random;//写一个彩票的生成代码： 1-33随机选7个不重复的数字；public class TestLuckyTicket { /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub   int[] luckTickets=new int[7];      Random r=new Random();   for(int i=0;i<luckTickets.length;i++){    luckTickets[i]=r.nextInt(8)+1;    for(int j=0;j<i;j++){     if(luckTickets[i]==luckTickets[j]){      i--;      break;     }    }   }   for(int i=0;i<luckTickets.length;i++){    System.out.print(luckTickets[i]+",");   } }}

public class TestPoet {  /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub   String str="床前明月光，疑是地上霜。举头望明月，低头思故乡。";   char[] poet=str.toCharArray();   int l=18;   boolean flag=true;   int i=0;   while(flag){    for(int j=l;j>=(0+i);){     System.out.print(poet[j]);     j=j-6;    }    System.out.println();    l++;    i++;    if(l==24){flag=false;}   } } }

import java.util.Scanner;public class JiuGongGe { /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub  @SuppressWarnings("resource")  Scanner s=new Scanner(System.in);  System.out.println("请输入一个大于等于3的奇数");  int length=s.nextInt();  if(length<3||length%2==0){   System.out.println("输入的数字不合法！");   return;  }   int[][] nineTable=new int[length][length];  int indexX=0;  int indexY=0;  indexY=(nineTable.length-1)/2;  nineTable[indexX][indexY]=1;  for(int i=1;i<nineTable.length*nineTable.length;i++){   indexX--;   indexY++;   if(indexY>=nineTable.length&&indexX>=0){    indexY=0;   }else if(indexX<0&&indexY<nineTable.length){    indexX=nineTable.length-1;   }else if(indexY>=nineTable.length&&indexX<0){    indexY--;    indexX=indexX+2;   }else if(nineTable[indexX][indexY]!=0){    indexY--;    indexX=indexX+2;   }   nineTable[indexX][indexY]=i+1;     }  for(int i=0;i<nineTable.length;i++){   for(int j=0;j<nineTable[i].length;j++){    System.out.print(nineTable[i][j]+" ");   }   System.out.println();   System.out.println();  }   } }