为什么这个方法调用不起作用?

时间:2012-05-03 00:54:32

标签: java methods

我正在创建一种方法来接受用户的输入并验证它以确保它是正确的。如果它是正确的,它将调用一个方法并输入用户输入。但由于某种原因,方法调用不起作用。它不会产生任何错误,它只是没有做到。我在代码的末尾放置了一个print语句,以确保它实际到达那里并确实如此,但由于某种原因,它只是没有像它应该的那样调用方法。如果我自己调用它并通过参数输入字符串,则另一种方法可以正常工作。

代码是:

public void getGetScheduledShowByFilmInput()////new - omar////
{
    BufferedReader reader;
    reader = new BufferedReader(new InputStreamReader(System.in));

    String filmInput;
    filmInput = "";

    boolean foundFilm;
    foundFilm = false;

    System.out.println("Here is a list of films that are currently showing:");
    for(Film film : films){
        System.out.println(film.getFilmName());
    }

    System.out.println("");
    System.out.println("Please type the film name that you wish to view the corresponding shows for and press enter.");
    System.out.println("Type 'exit' and press enter to exit this process.");

    while(foundFilm == false){
        try{
            filmInput = reader.readLine();
        }
        catch (IOException e){
            System.out.println("Error");
        }

        //If user enters "exit" then return.
        if(filmInput.equals("exit")){
            return;
        }

        //Check to see if the film name input by the user corresponds to any film showing.
        for(Film film : films){
            if(film.getFilmName() == filmInput){
                foundFilm = true;
                break;
            }
        }

        if(foundFilm = true){
            System.out.println("Film found.");
        }
        else{
            System.out.println("The film name you entered has not been recognised.  Please try again.");
        }
    }

    //Call the function and input the film name input by the user.
    getScheduledShowsByFilm(filmInput);  ////This is the code that seems to be the problem.
    System.out.println("reached bottom");

}

,第二种方法是:

 public void getScheduledShowsByFilm(String inputFilmName)
{
    ArrayList<Show> scheduledShows;
    scheduledShows = new ArrayList<Show>();
    for(Film film : films){
        if(inputFilmName == film.getFilmName()){
            for(Schedule schedule : schedules){
                scheduledShows.add(schedule.getShowsOfFilm(film));
                if(scheduledShows.get(scheduledShows.size() - 1) == null){
                    scheduledShows.remove(scheduledShows.size() - 1);
                }
            }
        }
    }

    for(Show show : scheduledShows){
        System.out.println("**********************************");
        show.getShowDetails();
        System.out.println("**********************************");
    }
}

当我自己调用它并手动输入参数时,第二种方法非常有效。

这可能非常简单,我不理解!哈哈,谢谢你的帮助:)

2 个答案:

答案 0 :(得分:2)

foundFilm永远不会是假的,因为你总是赋予它真实:

 if(foundFilm = true){
            System.out.println("Film found.");
 }

尝试将其更改为:

if(foundFilm)
{
   System.out.println("Film found.");
}

答案 1 :(得分:0)

getGetScheduledShowByFilmInput()getScheduledShowsByFilm(String)中,避免使用相等运算符(==)进行字符串比较。 ==运算符测试对象相等性,但是您想测试两个字符串是否包含相同的字符序列。因此,请改用equals

    //Check to see if the film name input by the user corresponds to any film showing.
    for(Film film : films){
        if(film.getFilmName().equals(filmInput)){
            foundFilm = true;
            break;
        }
    }

for(Film film : films){
    if(inputFilmName.equals(film.getFilmName())){
        for(Schedule schedule : schedules){
            scheduledShows.add(schedule.getShowsOfFilm(film));
            if(scheduledShows.get(scheduledShows.size() - 1) == null){
                scheduledShows.remove(scheduledShows.size() - 1);
            }
        }
    }
}