我正在开发一个从客户接收交易的系统。程序实际运行但当我即将进入新事务时，会出现以下错误：
线程中的异常＆＃34; main＆＃34; java.lang.NullPointerException at Java的机器.problem.pkg2.design.bakery（design.java:180）结果：1
我的代码是这样的：
public static int choice1,choice2,counter,type,tnumber=1000,i=0,x=0,tno=0;
public static char exit='y';
public static String code;
public static int []tcode;
public static Integer []codet;
public static String []tdate;
public static int []ttype;
public static String [][]order;
public static int []total;
public static String []timedelivery;
public static float []payment;
public static int []tablenumber;
public static DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
public static Date date = new Date();
public static DateFormat timeFormat = new SimpleDateFormat("HH:mm");
public static Date time = new Date();
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
void bakery()throws IOException{
mainmenu MM = new mainmenu();
System.out.println("\n+------------------------------------------------------+");
System.out.println("\t\tBu's Bakeshop\n[1] Product Menu\n[2] Transaction Menu\n[3] Exit\nEnter a number: ");
choice1 = Integer.parseInt(br.readLine());
if(choice1==1){
do{
System.out.println("\n+------------------------------------------------------+");
System.out.println("\t\tProduct Menu\n[1] View Product List\n[2] Search for a Product by Product Code\n[3] Back to Main Menu\nEnter a number: ");
choice2 = Integer.parseInt(br.readLine());
System.out.println("\n+------------------------------------------------------+");
if(choice2==1){
System.out.println("Product Code\tProduct Description\t\tAmount");
...
...
System.out.println(" C1010\tChocolate Mousse\t\t290.00");
}
else if(choice2==2){
counter=0;
do{
System.out.println("Enter Product Code: ");
code = br.readLine();
if(code.length() == 5){
char code0 = code.charAt(0);
char code1 = code.charAt(1);
char code2 = code.charAt(2);
char code3 = code.charAt(3);
char code4 = code.charAt(4);
if(code0=='C' || code0=='c'){
if(code1=='1'){
if(code2=='0'){
if(code3=='0'){
if(code4=='1'){
System.out.println("\n+------------------------------------------------------+");
...
...
else{
System.out.println("\n+------------------------------------------------------+");
System.out.println("Product Code not found.");
}
System.out.println("\n+------------------------------------------------------+");
System.out.println("Try searching for Product Code again? [Y/N] ");
exit = br.readLine().charAt(0);
}while(exit=='Y' || exit=='y');
MM.menu();
}
else if(choice2==3){
MM.menu();
}
else{
System.out.println("Invalid input.");
counter = 1;
}
}while(counter==1);
}
else if(choice1==2){
System.out.println("\n+------------------------------------------------------+");
System.out.println("\t\tTransaction Menu\n[1] New Transaction\n[2] View Transaction\n[3] Search for a Transaction by Transaction Code\n[4] Back to Main Menu\nEnter a number: ");
choice2 = Integer.parseInt(br.readLine());
if(choice2==1){
int sum=0,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10;
counter=0;
tcode[i] = tnumber;
tdate[i] = dateFormat.format(date);
do{
System.out.println("Transaction Type:\n[1] Dine In\n[2] Take Out\n[3] Delivery");
ttype[i] = Integer.parseInt(br.readLine());
if(ttype[i]<1 && ttype[i]>3){
System.out.println("Invalid input.\nPlease input [1] Dine In\n[2] Take Out\n[3] Delivery");
counter=1;
}
else if(ttype[i]==1){
tno++;
tablenumber[i] = tno;
}
else if(ttype[i]==3){
timedelivery[i] = timeFormat.format(time);
}
}while(counter==1);
do{
System.out.println("Product Code\tProduct Description\t\tAmount");
...
...
System.out.println("Enter Product Code: ");
code = br.readLine();
if(code.length() == 5){
char code0 = code.charAt(0);
char code1 = code.charAt(1);
char code2 = code.charAt(2);
char code3 = code.charAt(3);
char code4 = code.charAt(4);
if(code0=='C' || code0=='c'){
if(code1=='1'){
if(code2=='0'){
if(code3=='0'){
if(code4=='1'){
order[i][x] = "Belgian Chocolate Bliss";
x++;
do{
System.out.println("How many Belgian Chocolate Bliss? ");
c1 = Integer.parseInt(br.readLine());
if(c1<0){
System.out.println("Input only positive numbers.");
counter=1;
}
}while(counter==1);
int price = 430;
System.out.println("You bought "+c1+" Belgian Chocolate Bliss for "+(price*c1)+".00");
total[i] = total[i] + (price*c1);
}
...
...
else{
System.out.println("\n+------------------------------------------------------+");
System.out.println("Product Code not found.");
}
System.out.println("\n+------------------------------------------------------+");
System.out.println("Try searching for Product Code again? [Y/N] ");
exit = br.readLine().charAt(0);
}while(exit=='Y' || exit=='y');
do{
System.out.println("Total amount: "+total[i]+"\nAmount of Payment: ");
payment[i] = Float.parseFloat(br.readLine());
if(payment[i]==total[i]){
System.out.println("Received the exact amount. Thank you!");
}
else if(payment[i]>total[i]){
System.out.println("Change: "+(payment[i]-total[i])+". Thank you!");
}
else if(payment[i]<total[i]){
System.out.println("Insufficient Amount.");
}
}while(payment[i]<total[i]);
i++;
tnumber++;
}
else if(choice2==2){
if(i>0){
for(int h=0;h<i;h++){
for(int j=0;j<tcode.length;j++){
System.out.println("Transaction Code: "+tcode[i]);
for(j=0;j<tdate.length;j++){
System.out.println("Transaction Date: "+tdate[i]);
for(j=0;j<ttype.length;j++){
if(ttype[i]==1){
System.out.println("Transaction Type: Dine In\nTable Number: "+tablenumber[i]);
}
else if(ttype[i]==2){
System.out.println("Transaction Type: Take Out");
}
else if(ttype[i]==3){
System.out.println("Transaction Type: Delivery\nTime Called: "+timedelivery[i]);
}
for(j=0;j<order.length;j++){
System.out.println("Products Bought: ");
for(j=0;j<order[0].length;j++){
System.out.println(order[i][j]+"\n");
}
for(j=0;j<total.length;j++){
System.out.println("Total Amount: "+total[i]);
}
}
}
}
}
}
}
else{
System.out.println("No Transactions.");
}
}
}
else if(choice2==3){
System.out.println("Enter Transaction Code: ");
int tobesearched = Integer.parseInt(br.readLine());
List list = Arrays.asList(tcode);
if(list.contains(tobesearched)) {
int index = Arrays.asList(tcode).indexOf(tobesearched);
System.out.println("Transaction Number: "+tobesearched);
System.out.println("Transaction Date: "+tdate[index]);
if(ttype[index]==1){
System.out.println("Transaction Type: Dine In\nTable Number: "+tablenumber[index]);
}
else if(ttype[index]==2){
System.out.println("Transaction Type: Take Out");
}
else if(ttype[index]==3){
System.out.println("Transaction Type: Delivery\nTime Called: "+timedelivery[index]);
}
System.out.println("Products Bought: ");
for(int j=0;j<order[0].length;j++){
System.out.println(order[i][j]+"\n");
}
System.out.println("Total Amount: "+total[index]);
}
else{
System.out.println("Transaction Code not found.");
}
}
else{
System.out.println("\n+------------------------------------------------------+");
System.out.println("Invalid input.");
}
MM.menu();
}
}
似乎困境是代码<arrayname>[i]的困境。我怎么能解决这个问题？