arraylist

问题 I'm trying to get five random numbers printed that never repeat, based on a certain range provided by the user. Posted below is the code I have so far. Firstly, I don't know how to list the numbers found in the ArrayList, or even if I should use ArrayList over just an Array. Any thoughts? package h1p2; import java.util.ArrayList; public class test{ public void method (int min, int max){ //Declare and initialize arrays and index variables ArrayList<Integer> rangeOne = new ArrayList<Integer>();

问题 I'm trying to get five random numbers printed that never repeat, based on a certain range provided by the user. Posted below is the code I have so far. Firstly, I don't know how to list the numbers found in the ArrayList, or even if I should use ArrayList over just an Array. Any thoughts? package h1p2; import java.util.ArrayList; public class test{ public void method (int min, int max){ //Declare and initialize arrays and index variables ArrayList<Integer> rangeOne = new ArrayList<Integer>();

问题 Actually I want to sort Array List of objects. I am using Comparable interface for this purpose. It is completely working But the problem is that when I am sorting is is giving these two problems. All name who have 1st letter capital are coming together on the top and all name who have 1st letter small are coming together on the bottom. All the sorted Capital letters word are coming together after that all the small letter words are coming at bottom together. Here is my bean MyShares.java

问题 This question already has answers here : Understanding this removeAll java method with arrayList (3 answers) Closed 2 years ago . This methods duty is to remove all occurrences of the value toRemove from the arrayList. The remaining elements should just be shifted toward the beginning of the list. (the size will not change.) All "extra" elements at the end (however many occurrences of toRemove were in the list) should just be filled with 0. The method has no return value, and if the list has

问题 I want to add the toStrings from items in an Arraylist of Objects to a Jlist through a for loop. I tried this. for (int i = 0; i < customer.slist.size(); i++) { ((DefaultListModel) checkOutList.getModel()).addElement(customer.slist.toString());//slist is an array of objects. } But it didnt work. Also NetBeans tells me .addElement() is not a method for a JList when I tried checkOutList.addElement("anything") 回答1: instead of customer.slist.toString() try: customer.slist.get(i).toString(); in

问题 I'm a little lost here. I'm trying to add a custom object(with 3 integers, 1 double, and 1 date) to an arraylist when a button is clicked. I want the arraylist to be shown in another classes listview. So far this is what I have for the custom class: ublic class Record { private Integer squat, bench, dead; private double total; private Date dateTime; public Record(int squat, int bench, int dead, double total, Date date) { this.bench = bench; this.dateTime = date; this.dead = dead; this.squat =

问题 I'm having some trouble parsing a generic ArrayList with GSON. I've confirmed that this method works if the specific type for the ArrayList is specified (using no generics), but I'd like to write a method which works with generics. Based on other stack overflow's questions, this should work, and I can't really understand why it doesn't. It fails to parse the ArrayList so all I get is a collection of LinkedTreeMap . The generic method is below: public <T> List<T> listFromJson(@NonNull Class<T>

问题 I have an ArrayList of type String . I want to determine whether any element of this ArrayList starts with a specified string and if the ArrayList contains this element, then I want to get the index of this element. In addition, I do not want to loop this ArrayList to get the index of that element. For example : ArrayList<String> asd = new ArrayList<String>(); // We have an array list //We filled the array list asd.add("abcc trtiou"); asd.add("aiwr hiut qwe"); asd.add("vkl: gtr"); asd.add(

问题 I try to insert my ArrayList<LatLng> list1 with a lot of values like this: (99.9999999,99.9999999) to table in database MySQL, exacly to 1 column, something like this: row 1 (99.9999999,99.9999999) row 2 (99.9999999,99.9999999) row 3 (99.9999999,99.9999999) ... all to 1 column. In my opinion, currently i have a good method for this: String sql = "INSERT INTO table1 VALUES("; for(String s : list1) { sql = sql+"'"+s+"'"; } sql = sql+")"; stmt.executeUpdate(sql); but Android Studio underlines

问题 I have tablayout in my app,and i want to set recyclerview in tablayout fragment.if i set static String array it is working fine.but i dont know how can i access custom arraylist in fragment to set data in my recyclerview.following is my code can any one help me with that public class CategoriesActivity extends AppCompatActivity{ private Header myview; private ArrayList<SubcategoryModel> subct; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);