arraylist

问题 I have tried to load 6.000.000 (6 mio) strings of 64 characters in length in order to sort them in VBA. What I have noticed is : 1. When I use an Array the memory occupied is around 916 MB 2. When I use an ArrayList the memory occupied goes to 1.105 MB None of them is reasonable to me as the strings size is around 380 MB. What I doing wrong ? As the numbers of strings will grow rapidly I will face 'Out of memory' very soon. Any idea will be welcome. Demetres 回答1: Most of the issue is the fact

问题 I use ArrayList to store the 'shadows' for every rectangle in the level but when I iterate through the like this: for(int n = 0; n < shadows.size(); ++n){ g2d.fillPolygon(shadows.get(n)[0]); g2d.fillPolygon(shadows.get(n)[1]); g2d.fillPolygon(shadows.get(n)[2]); g2d.fillPolygon(shadows.get(n)[3]); g2d.fillPolygon(shadows.get(n)[4]); g2d.fillPolygon(shadows.get(n)[5]); } I get a java.lang.IndexOutOfBoundsException error that looks like this: Exception in thread "AWT-EventQueue-0" java.lang

问题 How would you extract the data as follows: I want to extract from this arraylist: [{itemname=Original, number=12}, {itemname=BBQ, number=23}, {itemname=CatchUp, number=23}] This array: {"Original":12,"BBQ":23,"CatchUp":23} Thanks in advance! Here's the code used to generate the hashmap: ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String,String>>(); for (int i = 0; i<7;i++) { HashMap<String,String> map = new HashMap<String,String>(); map.put("itemname",chips[i]); map.put(

问题 I need to find the most frequent words (n words, so if n = 5, the most frequent 5 words) in an ArrayList. private ArrayList<String> wordList = new ArrayList<String>(); public ArrayList<String> mostOften(int k) { ArrayList<String> lista = new ArrayList<String>(); Set<String> unique = new HashSet<String>(wordList); for (String key : unique) System.out.println(key + ": " + Collections.frequency(wordList, key)); return lista; } The function needs to return a list of the most frequent words,

问题 Thanks Marko. I rewrite the code. try to make it simple. this time it can really compile. but it can only delete duplicate items sit next to each other. for example, if i put in 1 2 3 3 4 4 5 1 -- the output is 1 2 3 4 5 1. it can't pick up the duplicate at the end. (BTW: new to this website, if make any display mess my apologies) here's the new code: import java.util.*; public class SetListDemo{ public static void main(String[] args){ SetListType newList = new SetListType(); Scanner keyboard

问题 I store all static data in the JSON file. This JSON file has up to 1000 rows. How to get the desired data without storing all rows as ArrayList ? My code, I'm using right now and I want to increase its efficiency. List<Colors> colorsList = new ObjectMapper().readValue(resource.getFile(), new TypeReference<Colors>() {}); for(int i=0; i<colorsList.size(); i++){ if(colorsList.get(i).getColor.equals("Blue")){ return colorsList.get(i).getCode(); } } Is it possible? My goal is to increase

问题 I need to select automatically all checkboxes when I launch my app in onViewCreated() . With this code: @Override public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); lv = (ListView)getView().findViewById(R.id.listview); displayPlanetList(); for (int i=0;i<plAdapter.getCount();i++) { Planet p=plAdapter.getItem(i); //if(p.getId()==3) { //System.out.println("NOME PIANETA:" + p.getName()); p.setSelected(true); //} p

问题 I am getting the data in HTML table format from external source - from xml.etree import ElementTree as ET s = """<table> <tr><th>Release</th><th>REFDB</th><th>URL</th></tr> <tr><td>3.7.3</td><td>12345</td><td>http://google.com</td></tr> <tr><td>3.7.4</td><td>456789</td><td>http://foo.com</td></tr> </table> """ For converting html table to dictionary table = ET.XML(s) rows = iter(table) headers = [col.text for col in next(rows)] for row in rows: values = [col.text for col in row] out = dict

问题 In this method I am receiving the ArrayList OkHttpHandler handler = new OkHttpHandler(MainActivity.this,new OkHttpHandler.MyInterface() { @Override public void myMethod(ArrayList result) { Toast.makeText(MainActivity.this, "Connection Succesful", Toast.LENGTH_LONG).show(); GridViewAdapter adapter = new GridViewAdapter(getApplicationContext(), R.layout.grid_item_layout, result); what I want is to send this arraylist to another activity in the gridiview. When the user clicks on the image in

问题 In this method I am receiving the ArrayList OkHttpHandler handler = new OkHttpHandler(MainActivity.this,new OkHttpHandler.MyInterface() { @Override public void myMethod(ArrayList result) { Toast.makeText(MainActivity.this, "Connection Succesful", Toast.LENGTH_LONG).show(); GridViewAdapter adapter = new GridViewAdapter(getApplicationContext(), R.layout.grid_item_layout, result); what I want is to send this arraylist to another activity in the gridiview. When the user clicks on the image in