我正在制作一个货币跟踪器来跟踪比特币的实时价值。
如果我在自己的 main 方法中运行它,"bitcoinlive"类可以正确运行,但是当我创建文件的实例时它将无法工作。我需要它来打印比特币的实时价值。
我尝试打印出变量"a53",但我不知道我做得是否正确。以下是 bitcoinlive 类的导入列表,因为它一直给我一条错误消息,并且在发布此内容时不允许将其与代码分开。
public static void main(String[] args) {
Dates d = new Dates();
String s = d.getDate();
System.out.println("Date is" + s);
W3 mywallet = new W3();
Bitcoinlive mybitcoinlive = new Bitcoinlive();
L3 myledger = new L3();
Scanner myscanner = new Scanner(System.in);
double buy = 0.0;
int choice = 0;
double bitcoin = 4000;
double USD = 20000;
while (choice != 5) {
System.out.println("Welcome! Enter a command. n"
+ "Enter 1) Buy Bitcoin n"
+ "Enter 2) Sell Bitcoin n"
+ "Enter 3) Print Balance n"
+ "Enter 4) Print History n"
+ "ENTER 5) Exit Programn");
choice = myscanner.nextInt();
if (choice == 1) {
System.out.println("How many? ");
buy = myscanner.nextDouble();
mywallet.add(buy);
bitcoin = bitcoin * buy;
USD = USD - bitcoin;
myledger.save(s);
System.out.println("you have bought:" + mywallet.numcoins);
System.out.println(USD);
System.out.println(mybitcoinlive.a53);
bitcoin = 4000;
} else if (choice == 2 && USD >= bitcoin) {
System.out.println("How many?");
buy = myscanner.nextDouble();
mywallet.subtract(buy);
System.out.println("you have sold:" + mywallet.numcoins);
USD = USD + bitcoin;
System.out.println(USD);
bitcoin = 4000;
myledger.save(s);
} else if (choice == 3) {
System.out.println("Balance:" + mywallet.numcoins);
} else if (choice == 4) {
System.out.println("Transaction history: ");
System.out.println("you have made" + myledger.getsize() + "transactions"
+ d.getDate());
} else if (choice == 5) {
// exit
break;
} else if (choice == 7) {
System.out.println(mybitcoinlive.price);
}
}
System.out.println("Bye");
}
这是我的单独课程
public class Bitcoinlive {
Double a53=0.0;
double price;
Double get() {
try {
String urlcoincapeth13 = "https://api.coinmarketcap.com/v1/ticker/bitcoin/";
Document docblocktradescoincapeth13 = Jsoup.parse(new URL(urlcoincapeth13).openStream(), "UTF-8", "", Parser.xmlParser());
String a13 = docblocktradescoincapeth13.toString();
int a23 = a13.indexOf("price_usd") + 13;
int a33 = a13.indexOf("price_btc") - 4;
String a43 = a13.substring(a23, a33);
a53 = Double.parseDouble(a43);
} catch (Exception e) {
System.out.println("Error accessing bitcoin values");
}
return a53;
}
}
您的类Bitcoinlive
将价格存储在名为 a53
的字段中。您可以通过调用 get()
来更新此字段。但是,看起来您从未调用get()
- 您只是在调用字段:
System.out.println(mybitcoinlive.a53);
尝试将该行替换为:
System.out.println(mybitcoinlive.get());
或者先刷新它:
mybitcoinlive.get();
System.out.println(mybitcoinlive.a53);