如何以更少的重复调用 set 方法。 (Java)

Question

你好，我有一堆 do while 语句用于我正在制作的程序，每个语句都有一个不同的 setMethod 在另一个 class 中定义，但是我想以更紧凑的方式执行此操作。我想知道某种循环是否可以做到这一点。或者如果你可以有一个 setMethod 数组。或者任何可以使此代码紧凑的东西。

contestant1 is an object of the class contestant information which contains the set methods for each field.

do {
    try {
        flag = false;
        System.out.println("Please enter your first name.");
        String firstName = Scanner.nextLine();
        contestant1.setName(firstName);
    } catch (InvalidInputException e) {
        System.out.println(e.getMessage());
        flag = true;
    }
} while (flag);

do {
    try {
        flag = false;
        System.out.println("Please enter your last name.");
        String lastName = Scanner.nextLine();
        contestant1.setLastName(lastName);
    } catch (InvalidInputException e) {
        System.out.println(e.getMessage());
        flag = true;
    }
} while (flag);

do {
    try {
        flag = false;
        System.out.println("Please enter your street number.");
        String streetNumber = Scanner.nextLine();
        contestant1.setStreetNumber(streetNumber);
    } catch (InvalidInputException e) {
        System.out.println(e.getMessage());
        flag = true;
    }
} while (flag);

Answer 1

String[] setMethodNames={"First Name","Last Name","Street"};
for(String s:setMethodNames){
    do{
        try{
            flag=false;
            System.out.println("Please enter your "+s+" :");
            String inp=scanner.nextLine();
            callSetFunction(contestant1,s,inp);
         }catch(InvalidInputException e){
            System.out.println(e.getMessage());
            flag = true;
         }
    }while(flag)
}


private void callSetFunction(Contestant contestant1,String s,String inp){
    switch(s){
        case "First Name":
            contestant1.setFirstName(inp);
            break
        case "Last Name":
            contestant1.setLastName(inp);
            break;
        case "Street":
            contestant1.setStreet(inp);
            break;
        default:
            //do something
    }
}

Answer 2

如果您使用的是 Java 8，您可以这样做：

List<String> labels = Arrays.asList(
    "Please enter your first name.",
    "Please enter your last name.",
    "Please enter your street number."
);

Function<String, Void> setters = Arrays.asList(
    contestant1::setName,
    contestant1::setLastName,
    contestant1::setStreetNumber
);

Iterator<String> label = labels.iterator();
for(Function<String, Void> setter : setters) {
    do {
        try {
            flag = false;
            System.out.println(label.next());
            String value = Scanner.nextLine();
            setter.apply(value);
        } catch (InvalidInputException e) {
            System.out.println(e.getMessage());
            flag = true;
        }
    } while (flag);
}

Answer 3

String[] setMethodNames={"FirstName","LastName","Street"};
Class cls = Class.forName("<qualifiedname>Contestant");
Class parameterTypes = String.class;

for(String s:setMethodNames){
    do{
        try{
            flag=false;
            System.out.println("Please enter your "+s+" :");
            String inp=scanner.nextLine();
            cls.getDeclaredMethod("set"+s, parameterTypes ).invoke(contestant1, inp);

         }catch(InvalidInputException e){
            System.out.println(e.getMessage());
            flag = true;
         }
    }while(flag);
}

你也可以使用反射并调用setter

如何以更少的重复调用 set 方法。 (Java)

How to call set methods with less repetition . (Java)

java

syntax