试图为我的java 1类创建一个电影管理器，但是我很难弄清楚如何使冒泡排序方法与arraylist一起使用。 arraylist包含(String name, String genre, String actor, int year)的元素，我希望能够按我想要的任何元素对其进行排序。我使用switch语句提示用户要对其进行排序，然后我将使用重载方法根据发送它的元素进行搜索。
我尝试在线查找一堆类似的代码并使用对他们有用的代码，但是我仍然遇到问题，我不确定在哪里。实际上，我认为我有几处错误，但不确定如何解决。
public void bubbleSort(ArrayList movieList)
{
movieList temp;
for (int i = 0; i < movieList.size(); i++)
{
for (int j = 1; j < (movieList.size() - i); j++)
{
if (this.movieList.get(i).getName().compareToIgnoreCase(String.valueOf(i - 1)) > 0)
{
// System.out.println("Movie found : %s%n", this.movieList);
temp = movieList.get(i);
movieList.set(i, movieList.indexOf(i-1));
movieList.indexOf(i-1) = temp;
}
}
}
}
我只需要对数组进行排序的方法，然后将其显示给用户（我已经可以将其显示回去了。）
*编辑 这是我到目前为止的全部代码
MovieManager类
import java.util.Scanner;
public class MovieManager {
static Scanner stdin = new Scanner(System.in);
public static void main(String[] args)
{
// Movie movie = new Movie();
Driven drivenClass = new Driven();
drivenClass.fillArray();
boolean kill = false;
while (!kill) //!lose validation boolean?
{
System.out.printf("Customer or Employee? %n1: Customer %n2: Employee %nQ: Quit %n");
switch (stdin.next()) //switch to determine if user is customer or employee.
{
case "1": //Customer
//copy and edit employee menu
break;
case "2": //Employee
System.out.println("Enter password to continue or anything else to go back.");
while (stdin.next().equals("123456"))
{
boolean quit = false;
while (!quit) //loop to allow sequential actions
{
System.out.printf("What would you like to do? %n1: Display %n2: Sort %n3: Search %n4: Add %n5: Remove %nQ: Quit %n");
switch (stdin.next())
{
case "1": //display
drivenClass.displayMovies();
//add display by type
break;
case "2": //sort
drivenClass.sortMovies();
break;
case "3": //search
drivenClass.searchMovies();
break;
case "4": //add
drivenClass.addMovies();
break;
case "5": //remove
drivenClass.removeMovies();
break;
case "q":
quit = true;
break;
case "Q":
quit = true;
break;
default:
System.out.println("Must be a number 1-5");
// stdin.next();
}
}
}
break;
case "q": //quit
kill = true;
break;
case "Q": //quit
kill = true;
break;
default:
System.out.println("Must enter a 1, 2, or Q.");
stdin.next();
}
}
}
}
驱动类（我在尝试弄清楚它时使用了一些东西，因此请忽略它）
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class Driven {
Scanner stdin = new Scanner(System.in);
public ArrayList<Movie> movieList = new ArrayList<>();
public void fillArray() //method to populate ArrayList initially
{
movieList.add(new Movie("Kill All Humans", "Sci-fi", "Robot Assassin", 2138));
movieList.add(new Movie("42", "Sci-fi", "Life, the universe, and everything", 5462));
movieList.add(new Movie("Bloody Billy 17 -Yet Another Bloodfest", "Action", "B. J. Blackowitz", 1990));
movieList.add(new Movie("Always Watching", "Documentary", "Big Brother", 1984));
movieList.add(new Movie("Robot Samurai", "Kids", "Deus Ex Machina", 2012));
movieList.add(new Movie("Giant Nuclear Frogs from the South", "Suspense", "Chuck Norris", 1998));
movieList.add(new Movie("How to Make Cyanide from Apple Seeds", "Educational", "Adolf Hitler", 1940));
movieList.add(new Movie("Two Birds with No Stones", "Martial-Arts", "Bruce Lee, Tim Cook, Edward Snowden", 1969));
movieList.add(new Movie("Slow Internet!!!", "Suspense", "Sarah Connar, Linus Torvalds", 2004));
movieList.add(new Movie("I Know Kung Fu", "Romance", "Steven Seagal, Jackie Chan", 2007));
movieList.add(new Movie("Space Voyage", "Sci-fi", "Kirk, Spock", 1967));
movieList.add(new Movie("Pointless Slaughter", "Thriller", "Stephen Hawking, Mike Tyson", 1999));
movieList.add(new Movie("50 Shades of Death 2: Death before Diplomacy", "Thriller", "Donald Trump, Barrack Obama, Lots of Guns", 2023));
movieList.add(new Movie("MTV (Music Television) - The Movie", "Action", "Bob Ross", 2010));
movieList.add(new Movie("Spinach Sailor", "Documentary", "Popeye, Einstein", 1949));
movieList.add(new Movie("Applegeddon - End of Humanity", "Documentary", "Steve Jobs, Steve Wozniak", 2099));
}
public void addMovies() //method to add movies to full list
{ //!when adding 2 in a row it automatically puts a empty name
System.out.println("Input movie name:");
String names = stdin.nextLine();
System.out.println("Input movie genre:");
String genre = stdin.nextLine();
System.out.println("Input movie actors/actresses:");
String actor = stdin.nextLine();
System.out.println("Input movie year:");
while (!stdin.hasNextInt())
{
System.out.println("Must be a whole number");
stdin.next();
}
int year = stdin.nextInt();
movieList.add(new Movie(names, genre, actor, year));
System.out.println("Movie added.");
}
public void removeMovies() //method to delete movies from full list
{ //! add way to quit if chosen by accident
System.out.println("Enter name of movie to remove.");
String search = stdin.nextLine();
for (int i = 0; i < movieList.size(); i++)
{
if (movieList.get(i).getName().equalsIgnoreCase(search))
{
System.out.printf("Remove this movie Y/N. %nName: %s %nGenre: %s %nActor: %s %nYear: %s %n %n", movieList.get(i).getName(), movieList.get(i).getGenre(), movieList.get(i).getActor(), movieList.get(i).getYear());
if (stdin.next().equalsIgnoreCase("y"))
{
movieList.remove(i);
System.out.println("Movie removed.");
}
}
}
}
public void displayMovies() //method to output the full list
{
for (Movie movie : movieList)
{
System.out.printf("Name: %s %nGenre: %s %nActor: %s %nYear: %s %n %n", movie.getName(), movie.getGenre(), movie.getActor(), movie.getYear());
}
}
public void sortMovies()
{
System.out.printf("Sort by: %n1: Title %n2: Genre %n3: Actor/actress %n4: Year %n");
boolean validChoice = false;
while (!validChoice)
{
switch (stdin.next())
{
case "1": //sort by title
System.out.println("Enter sort method. 1 for bubble sort. 2 for selection sort.");
// displayMovies();
bubbleSort(movieList);
// Collections.sort(movieList, new Comparator<Movie>() {
// @Override
// public int compare(Movie o1, Movie o2) {
// return 0;
// }
// });
// movieList.get().getName().sort();
// movieList.sort(Collections.reverseOrder());
// System.out.println("sorted");
// displayMovies();
// movieList.sort(movieList.get(i).getName());
// Collections.sort(movieList.get().getName());
validChoice = true;
break;
case "2": //sort by genre
System.out.println("Enter sort method. 1 for bubble sort. 2 for selection sort.");
validChoice = true;
break;
case "3": //sort by actor
System.out.println("Enter sort method. 1 for bubble sort. 2 for selection sort.");
validChoice = true;
break;
case "4": //sort by year
System.out.println("Enter sort method. 1 for bubble sort. 2 for selection sort.");
validChoice = true;
break;
default:
validChoice = false;
System.out.println("Must enter 1-4");
stdin.next();
}
}
}
public void searchMovies() //method to search for specific movie name
{ //!make it so spacing doesnt matter
System.out.println("Enter name of movie to find.");
String search = stdin.nextLine().toLowerCase();
for (int i = 0; i < movieList.size(); i++) {
if (movieList.get(i).getName().matches(search)) {
System.out.printf("%s.%nName: %s %nGenre: %s %nActor: %s %nYear: %s %n %n", i+1, movieList.get(i).getName(), movieList.get(i).getGenre(), movieList.get(i).getActor(), movieList.get(i).getYear());
}
}
}
// public ArrayList setmovieList()
// {
// this.movieList = movieList;
// }
public ArrayList getmovieList()
{
return movieList;
}
private ArrayList bubbleSort()
{
getmovieList();
Movie temp;
for (int i = 0; i < movieList.size(); i++)
{
for (int j = 1; j < (movieList.get() - i); j++)
{
Movie jMovie = movieList.get(j).getMovie();
// String compareLists = movieList.get(i-1).getName().toLowerCase();
// System.out.println(compareLists);
if (movieList.get(i).(movieList.get(i - 1).getName()) < 0)
// if (movieList.get(i).getName().toLowerCase().matches(compareLists))
{
System.out.println("Movie found ");
temp = movieList.get(i);
movieList.set(i, movieList.get(i-1));
movieList.set(i-1, temp);
}
}
}
}
// public ArrayList<Movie> getmovieList() //!Lose?
// {
// return movieList;
// }
}
//// Java program to demonstrate working of Collections.sort()
//import java.util.*;
//
//public class Collectionsorting
//{
// public static void main(String[] args)
// {
// // Create a list of strings
// ArrayList<String> al = new ArrayList<String>();
// al.add("Geeks For Geeks");
// al.add("Friends");
// al.add("Dear");
// al.add("Is");
// al.add("Superb");
//
// /* Collections.sort method is sorting the
// elements of ArrayList in ascending order. */
// Collections.sort(al);
//
// // Let us print the sorted list
// System.out.println("List after the use of" +
// " Collection.sort() :\n" + al);
// }
//}
电影课
import java.util.ArrayList;
public class Movie {
private String name;
private String genre;
private String actor;
private int year;
public Movie(String name, String genre, String actor, int year){
this.name = name;
this.genre = genre;
this.actor = actor;
this.year = year;
} //movie constructor
// public Movie() { }
public int getYear()
{
return year;
}
public String getActor()
{
return actor;
}
public String getGenre()
{
return genre;
}
public String getName()
{
return name;
}
public Movie getMovie(int i)
{
Movie temp = Driven.(getName(), getGenre().indexOf(i), getActor(i), getYear(i));
return Movie();
}
}
答案 0 :(得分：0)
我会给你一些提示。冒泡排序应该只需要从索引1开始对列表进行一次遍历。将它与它下面的索引进行比较。如果compareTo返回<0，则将该项目保留在原处。否则，交换两个项目，然后再次将其与左侧的项目进行比较。因此，第二个for循环应朝索引0倒数，并且当compareTo返回> = 0时，应中断该循环。
您已经接近这一行，但是您正在与i-1的字符串版本进行比较，而不是与i-1列表中的字符串进行比较。
if (this.movieList.get(i).getName().compareToIgnoreCase(movieList.get(i - 1).getName()) < 0)