如何以较少的重复次数调用set方法。 （JAVA）

Question

你好我有一些我正在制作的程序的while语句，并且每个语句在另一个类中定义了不同的setMethod但是我想以更紧凑的方式执行此操作。我想知道是否某种循环可以做到这一点。或者，如果你有一个setMethod数组。或任何能使这段代码变得紧凑的东西。

  

contestant1是班级参赛者信息的对象，其中包含每个领域的设定方法。

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={"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);
}

您还可以使用反射和调用setter

Answer 2

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 3

如果你正在使用Java 8，你可以这样做：

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);
}