此代码尚未完成，但我一直在输出txt文件（cpu.txt）在输出中变为“null”的问题，是否有人知道我哪里做错了？感谢。
这是输出：
--------------------配置：--------------------
BINGO CALL IS: G50
PLAYER CARDS:
B I N G O B I N G O
1 21 38 58 68
5 29 31 51 73
15 20 F 59 67
4 30 39 53 74
11 28 33 48 69
7 30 32 49 69
8 27 35 58 63
3 17 F 57 68
11 18 45 52 71
12 16 33 54 70
CPU CARDS:
B I N G O B I N G O
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
null null null null null
B 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
I 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
N 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
G 46 47 48 49 * 51 52 53 54 55 56 57 58 59 60
O 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
当前可用积分：0分。 涂抹板 2.打电话给Bingo！ 3.使用奖金（1000分） 4.下一个电话
import java.util.Random;
import java.io.*;
import java.util.Scanner;
public class Bingo_D {
public static void callBoard(int[] un, int turns) {
int t = 1;
int i = 1;
int[] bingo = new int[76];
System.out.print("B" + "\t");
String star= "nothing";
for ( i=1; i < bingo.length; i++){
bingo[i] = i;
for (t = 1; t < un.length; t++){
if(un[t] == bingo[i]){ //un = call, bingo = board
star = Integer.toString(bingo[i]);
star = "*";
System.out.print(star + "\t");
break;
} else if (t == i){
System.out.print(bingo[i] + "\t");
}
}
if (bingo[i] % 15 == 0 ){
System.out.println();
} if (bingo[i] == 15) {
System.out.print("I" + "\t");
} if (bingo[i] == 30) {
System.out.print("N" + "\t");
} if (bingo[i] == 45) {
System.out.print("G" + "\t");
} if (bingo[i] == 60) {
System.out.print("O" + "\t");
}
}
}
public static String randomCall(){
Random object = new Random();
int number = 1+object.nextInt(75);
if (number > 0 && number < 16 ){
System.out.print("B" + number );
} else if ( number > 15 && number < 31){
System.out.print("I" + number );
} else if ( number > 30 && number < 46){
System.out.print("N" + number );
} else if ( number > 45 && number < 61){
System.out.print("G" + number );
} else {
System.out.print("O" + number );
}
String real = Integer.toString(number);
return real;
}
public static boolean checkWinner(String[] check){
int b = 1;
int i = 6;
int n = 11;
int g = 16;
int o = 21;
//vertical victory
while(true){
if (n == 13 && check[b].equals("*") && check[i].equals("*") && check[n].equals("F") && check[g].equals("*") && check[o].equals("*")||
n == 38 && check[b].equals("*") && check[i].equals("*") && check[n].equals("F") && check[g].equals("*") && check[o].equals("*")){
return true;
} else if (check[b].equals("*") && check[i].equals("*") && check[n].equals("*") && check[g].equals("*") && check[o].equals("*")){
return true;
} else {
if(b < 5 || b > 25 && b < 30) {
b++; i++; n++; g++; o++;
}else if( b == 5) {
b+=21; i+=21; n+=21; g+=21; o+=21;
} else {
break;
}
}
}
//horizontal victory
int m = 1;
int p = 2;
int x = 3;
int u = 4;
int w = 5;
while (true){
if (x == 13 && check[m].equals("*") && check[p].equals("*") && check[x].equals("F") && check[u].equals("*") && check[w].equals("*")||
x == 38 && check[m].equals("*") && check[p].equals("*") && check[x].equals("F") && check[u].equals("*") && check[w].equals("*")){
return true;
} else if (check[m].equals("*") && check[p].equals("*") && check[x].equals("*") && check[u].equals("*") && check[w].equals("*")){
return true;
} else if (m < 46){
m+=5; p+=5; x+=5; u+=5; w+=5;
} else {
break;
}
} //diagonal victory
if (check[1].equals("*") && check[7].equals("*") && check[13].equals("F") && check[19].equals("*") && check[25].equals("*")||
check[5].equals("*") && check[9].equals("*") && check[13].equals("F") && check[17].equals("*") && check[21].equals("*")||
check[26].equals("*") && check[32].equals("*") && check[38].equals("F") && check[44].equals("*") && check[50].equals("*")||
check[30].equals("*") && check[34].equals("*") && check[38].equals("F") && check[42].equals("*") && check[46].equals("*")){
return true;
} else
return false;
}
public static void main(String[] args)throws FileNotFoundException{
int [] stars = new int[51];
int [] starstwo = new int[51];
int e = 0;
String[] b = new String[51];
String[] btwo = new String[51];
int tob = 1;
int i = 0;
int itwo = 0;
int cou = 1;
int coutwo = 1;
String star = "";
String startwo = "";
int totalBonus = 0;
int bon =0;
int secondChoice = 0;
int thirdChoice = 0;
for( int turns = 1; turns < 200; turns++){
System.out.print("BINGO CALL IS: ");
String replace = randomCall();
int[] call = new int[76];
int randomNum = Integer.parseInt(replace);
call[turns] = randomNum;
System.out.println();
System.out.println();
File player = new File("player.txt");
Scanner second = new Scanner(player);
System.out.println("PLAYER CARDS:");
//Reformatting the txt file
System.out.format("%3s%4s%4s%4s%4s\t\t\t%3s%4s%4s%4s%4s%n", "B", "I", "N", "G", "O", "B", "I", "N", "G", "O");
for (i= 1; i < 51; i++){
for( cou = 1; cou < 51; cou++){
if ( i == stars[cou]){
b[i] = second.next();
b[i] = "*";
star = "*";
System.out.printf("%4s", star + "\t");
}
}
if ( !star.equals("*")){
b[i] = second.next();
System.out.printf("%s", b[i] + "\t");
}
if(star.equals("*")){
star = "nothing";
}
if(i == bon && !b[i].equals("*")){
b[i]= second.next();
b[i]= "F";
System.out.printf("%s","F" + "\t");
}
if(i % 5 == 0) {
System.out.println();
}
}
System.out.println();
File cpuu = new File("cpu.txt");
Scanner secondtwo = new Scanner(cpuu);
System.out.println("CPU CARDS:");
//Reformatting the txt file
System.out.format("%3s%4s%4s%4s%4s\t\t\t%3s%4s%4s%4s%4s%n", "B", "I", "N", "G", "O", "B", "I", "N", "G", "O");
for (itwo= 1; itwo < 51; itwo++){
for( coutwo = 1; coutwo < 51; coutwo++){
if ( itwo == starstwo[coutwo]){
btwo[itwo] = secondtwo.next();
btwo[itwo] = "*";
startwo = "*";
System.out.printf("%4s", startwo + "\t");
}
}
if ( !startwo.equals("*")){
btwo[itwo] = secondtwo.next();
System.out.printf("%s", btwo[itwo] + "\t");
}
if(startwo.equals("*")){
startwo = "nothing";
}
if(itwo == bon && !b[i].equals("*")){
btwo[itwo] = second.next();
btwo[itwo] = "F";
System.out.printf("%s","F" + "\t");
}
if(itwo % 5 == 0) {
System.out.println();
}
}
System.out.println();
System.out.println();
callBoard(call,turns);
System.out.println();
System.out.println("current points available: " + totalBonus + " point." );
System.out.println(" 1. Daub board");
System.out.println(" 2. Call Bingo!");
System.out.println(" 3. Use bonus (1000 points)");
System.out.println(" 4. Next call");
Scanner input = new Scanner(System.in);
long var = System.currentTimeMillis() / 1000;
int choice = input.nextInt();
if(choice == 1){
long varl = System.currentTimeMillis() / 1000;
if (varl - var <= 3){
int bonus = 400;
for ( e = 1; e < 51; e++){
if ( replace.equals(b[e])){
totalBonus+=bonus;
System.out.println("you daubed " + replace + " on your board(s), " + bonus + " points earned.");
stars[tob]=e;
tob++;
break;
}else if(e==50){
int penalty = 500;
totalBonus-=penalty;
System.out.println("You do not have "+ replace + " on your board(s), 500 points penalty");
}
}
} else if(varl - var == 4) {
int smallBonus = 200;
for ( e = 1; e < 51; e++){
if ( replace.equals(b[e])){
totalBonus+=smallBonus;
System.out.println("you daubed " + replace + " on your board(s), " + smallBonus + " points earned.");
stars[tob]=e;
tob++;
break;
}else if(e==50){
int penalty = 500;
totalBonus-=penalty;
System.out.println("You do not have "+ replace + " on your board(s), 500 points penalty");
}
}
}else{
for ( e = 1; e < 51; e++){
if ( replace.equals(b[e])){
System.out.println("you daubed " + replace + " on your board(s).");
stars[tob]=e;
tob++;
break;
}else if(e==50){
int penalty = 500;
totalBonus-=penalty;
System.out.println("You do not have "+ replace + " on your board(s), 500 points penalty");
}
}
}
secondChoice = input.nextInt();
if (secondChoice == 2){
if (checkWinner(b) == true){
System.out.println("BINGO! congratulation, you have won!");
System.exit(0);
} else {
System.out.println("CHEATER! you lose!");
System.exit(0);
}
}
if(secondChoice == 3){
if( totalBonus >= 1000 ){
Random object = new Random();
bon = 1+object.nextInt(50);
for(int w = 0; w < 10; w++){
if( b[bon].equals("*")){
bon = 1+object.nextInt(50);
}
} System.out.println("Bonus daubs at " + b[bon]);
if (!b[bon].equals("*")) {
System.out.println("Bonus daubs at " + b[bon]);
}
} else {
System.out.println("Not enough Bonus points.");
}
thirdChoice = input.nextInt();
}
if (secondChoice == 4 || thirdChoice == 4){
for ( k = 1; k < 51; k++){
if ( replace.equals(starsCpu[k])){
System.out.println("The computer daubed " + starsCpu[k]);
starsCpu[com] = k;
com++;
if (checkWinner(a) == true){
System.out.println("BINGO! , computer has won!");
}
}else if (k == 50){
System.out.println("The computer do not have " + replace);
}
}
}
}//end of first choice
}
}
}
答案 0 :(得分：0)
当你写
时，你正在阅读并丢弃文件中的大量内容 if ( itwo == starstwo[coutwo]){
btwo[itwo] = secondtwo.next();
btwo[itwo] = "*";
然后，当你写下
btwo[itwo] = secondtwo.next();
System.out.printf("%s", btwo[itwo] + "\t");
没有什么可读的。
但是我仍然不明白这是如何导致你的文本文件被删除和替换的，就像你说的那样。您的示例中没有代码会擦除或写入您的文本文件。