在以下代码中，我得到了Unreachable catch block for IOException。 IOException } catch (IOException e){中class driver {
public static void main(String[] args) {
// TODO Auto-generated method stub
Customer forrest = new Customer("Forrest Gump", 1,
"42 New Street, New York, New York");
Customer random = new Customer("Random Name", 2,
"44 New Street, New York, New York");
Customer customer[] = { null, forrest, random };
int whichOption = 1;
int id = 0;
char action = ' ';
char accSrc = ' ';
char accDest = ' ';
double amount = 0;
BankAccount src = null;
do {
try{
// process JOptionPane input information
String input = JOptionPane
.showInputDialog("Please enter your transaction information: ");
Scanner s = new Scanner(input);
id = Integer.parseInt(s.next());
action = Character.toUpperCase((s.next().charAt(0)));
if (action == 'T') {
amount = s.nextDouble();
accSrc = s.next().charAt(0);
accDest = s.next().charAt(0);
} else if (action == 'G' || action == 'I') {
accSrc = s.next().charAt(0);
} else {
// if D,W
amount = s.nextDouble();
accSrc = s.next().charAt(0);
}
} catch (IOException e){
}
// taking action accordingly (T)ransfer, (D)eposit, (W)ithdraw, (I)nterest
if (action == 'T') {
(customer[id].getAccount(accSrc)).transfer(amount,
customer[id].getAccount(accDest));
} else if (action == 'G') {
System.out.println("The current balance on your " + accSrc
+ " account is "
+ customer[id].getAccount(accSrc).getBalance() + "\n");
} else if (action == 'D') {
(customer[id].getAccount(accSrc)).deposit(amount);
} else if (action == 'W') {
(customer[id].getAccount(accSrc)).withdraw(amount);
} else if (action == 'I') {
(customer[id].getAccount(accSrc)).computeInterest();
}
whichOption = JOptionPane
.showConfirmDialog(null , "Do you want to continue?");
System.out.println("The balance on " + customer[id].getName()
+ " auto account is " + customer[id].A.balance);
System.out.println("The balance on " + customer[id].getName()
+ " savings account is " + customer[id].S.balance);
System.out.println("The balance on " + customer[id].getName()
+ " checkings account is " + customer[id].C.balance);
System.out.println("The balance on " + customer[id].getName()
+ " loan account is " + customer[id].L.balance + "\n");
} while (whichOption == 0);
}
}
的问题声明正文错误（带下划线）永远不会抛出此异常吗？
{{1}}
答案 0 :(得分：11)
这是因为您在try/catch内执行的任何操作都不会抛出IOException。
根据扫描程序javadoc
大多数Scanner类方法都抛出FileNotFoundException（这不适用于您的情况，因为没有从文件中读取）（或）IllegalArgumentException（或）IllegalStateException
您需要将IOException更改为上述任一异常（或）删除try / catch。
答案 1 :(得分：4)
您可以删除IOException和try catch，因为try catch中的所有语句都没有抛出此异常
答案 2 :(得分：3)
好像你在try区块正在抛出IOException
答案 3 :(得分：3)
该try块中没有方法调用抛出IOException，这就是catch是无法访问的代码的原因。
您可以安全地删除try和catch，因为这种情况永远不会发生。
答案 4 :(得分：3)
您的catch块为空，表示您无论如何都不会真正处理异常。你可能在那里有一些代码让你抓住它，但现在你已经没有它了。只需移除整个周围try-catch，就不会有其他问题。
答案 5 :(得分：1)
try/catch块为空，代码不是抛出IOException，但它可能抛出其他异常。