如何为同一方法传递不同的 object 类型，而不是在 java 中编写具有相同功能和返回类型的两个方法

Question

here is my methods i want to make it dynamic which should accept class type as parameter and then i can use that in my predicate i have tried using instanceof but didnt work

public static String setStatus(List<SmeObject> s) {
    String finalStatus = "";
    Predicate<SmeObject> ifAllCompleted = x.getStatus().equals("Completed");
    Predicate<SmeObject> ifAllNotStarted = x.getStatus().equals("Not Started");

    if (s.stream().allMatch(ifAllCompleted)) {
        finalStatus = "Complete";
    } else if (s.stream().allMatch(ifAllNotStarted)) {
        finalStatus = "Not Started";
    } else {
        finalStatus = "In-progress";
    }
    return finalStatus;
}

public static String setStatus(List<ControllerObject> s) {
    String finalStatus = "";
    Predicate<ControllerObject> ifAllCompleted = x.getStatus().equals("Completed");
    Predicate<ControllerObject> ifAllNotStarted = x.getStatus().equals("Not Started");

    if (s.stream().allMatch(ifAllCompleted)) {
        finalStatus = "Complete";
    } else if (s.stream().allMatch(ifAllNotStarted)) {
        finalStatus = "Not Started";
    } else {
        finalStatus = "In-progress";
    }
    return finalStatus;
}

Answer 1

If ControllerObject and SmeObject share a common parent that exposes the getStatus() method, then you may want to make your method take a list with a List<? extends CommonObjectSuperType> List<? extends CommonObjectSuperType> :

public static String setStatus(List<? extends CommonObjectSuperType> s) {
    String finalStatus = "";
    Predicate<CommonObjectSuperType> ifAllCompleted = x.getStatus().equals("Completed");
    Predicate<CommonObjectSuperType> ifAllNotStarted = x.getStatus().equals("Not Started");

    ...
}

If, however, ControllerObject and SmeObject do not have a common parent that exposes getStatus() and you can't change them, then you're left with the option of making the caller send in a predicate by making the method generic:

public static <T> String setStatus(List<T> s, Predicate<T> allCompletedTest,
        Predicate<T> allNotStartedTest) {
    //use incoming predicates instead of creating them in the method
    ...
}

Then the caller will create the predicates in the context of the actual type.