I am new in Java so please be patient.
It is common to map (convert) lists to lists. Some languages have a map method, some (C#) Select. How is this done with ... |
It would be nice to use for (String item: list), but it will only iterate through one list, and you'd need an explicit iterator for the other list. Or, you ... |
Is there something like a two sided list in Java? Maybe a third party implementation?
Here a little example to demonstrate what I have in mind.
Original state:
A: 0-1-2-3
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I have a Set of keys and a List of key/value pairs. The values are of the form Long,BigInteger.
// key/values pairs: Long,BigInteger
List<Object[]> values;
// id list that corresponds to the keys for ...
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I have a list of Customers. Each customer has an address and some customers may actually have the same address. My ultimate goal is to group customers based on their address. ... |
How can I get a HashMap to a List? Something like:
Map<String, Horse> horses = new HashMap<String, Horse>();
ArrayList<Horse> = horses.toArray();
?
Thanks
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given the following code?
final Map<String, List<E>> map = new HashMap<String, List<E>>();
List<E> list = map.get(mapKey);
if (list == null) {
list = new ArrayList<E>();
map.put(mapKey, list);
}
list.add(value);
If there ... |
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I am using Java and I am looking for String Collections (Sets and Lists) that are optimized in space and are fast. My strings are of fixed size: either 3 or ... |
I want to have a Sorted map as follows:
srcAddr, dstAddr, srcPort, dstPort, protocol as keys
and a List of values as
packetLength, timeArrival for each key.
Is it possible to implement ... |
Possible Duplicate:
Clearest way to combine two lists into a map (Java)?
Given this:
List<Integer> integers = new ArrayList<Integer>();
List<String> ...
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I didnt get the sense of Maps in Java. When is it recommended to use a Map instead of a List?
thanks in advance,
nohereman
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Edit: I've gotten a couple of answers that say what I already said in the question. What I am really interested in is finding corroborating reference material.
I am looking at a ... |
How expensive is calling size() on List or Map in Java? or it is better to save size()'s value in a variable if accessed frequently?
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Collections.unmodifiableList(...) returns a new instance of a static inner class UnmodifiableList. Other unmodifiable collections classes are constructed same way.
Were these classes public, one had two advantages:
- ability to indicate a more specific ...
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I am looking for a Java class that offers both Map (fast lookup) and List (determinate order) characteristics. Any advice?
Thanks!
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How to sort (any kind of sorting) a key of a map(treemap or hashmap)
i have a problem and it goes like this.
i have a map that has a key of ... |
is there a way to sort this numbers stored in a string variable?
TreeMap<String,List<QBFElement>> qbfElementMap = new TreeMap<String, List<QBFElement>>();
this is the map where the key is :
27525-1813,
27525-3989,
27525-4083,
27525-4670,
27525-4911,
27526-558, ...
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I am having the below object
List<Map<String, Object>> listMap = new ArrayList<Map<String, Object>>();
How do i sort this based on the value ("Object") in the Map?
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I am getting a list of results in a map for a particular key. How to sort it?
Thanks in advance.
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There are cases where you use a List, be it array or linked. There are other situations where you use a Map, in java, or Dictionary or something else similar.
Why would ... |
I have one List which contain one map i want to iterate is
List<Map<String, Object>> featureService=featureSubscriptionDao.getUnsubscribedSevice();
my dao method is
@Override
public List<Map<String, Object>> getUnsubscribedSevice() {
String sql="select * from ...
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I have a method which is returning List<Map<String,Object>>.
How to iterate over a list like List<Map<String,Object>>?
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Since all of them are immutable, why would one want it?
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I'm looking for a program that will list the variable names in my Java application, and any non-primitive (preferrably any non-SDK) Object to the class that it's defined in.
Something along the ... |
I have a list of maps as follows
[[AdGenres-b:key:[177, 184],MusicalStyles-b:key:[30],SongTitle:[What
I've
Done],ArtistName:[LinkinPark],MusicVideoRating:[TV-14],MusicalStyles-b:value:[Rock],PlayId:[1367],AdGenres-b:value:[Rock
- Rock, Rock - Alternative],MusicVideoProvider:[Warner Music Group],
AssetId:[91744]],
[[AdGenres-b:key:[177, 184],MusicalStyles-b:key:[30],SongTitle:[What
... |
I am just trying to get everything straight in my mind. When I use lists or maps in Java, the maps and lists don't actually store a copy of the object, ... |
I have problem with this code,when I add map object to list,all previous added object will be changed.how can I declare map as non static?
for(Statment){
map.put(Key,value), ...
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The following code explains my problem:
interface f1 {}
interface f2 extends f1{}
1. List<? extends f1> l1 = new ArrayList<f2>();
2. Map<String, ? extends f1> m1 = new HashMap<String, f2>();
3. Map<String, List<? extends f1>> ...
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I am not able to convert the value which is the List<String>, of the Map into the String.
Source code is as follows:
Map<String ,List<String>> profileFields)
String argValue[] = null;
int ...
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I have a XML data from a SOAP Response like in the following example:
<EMP>
<PERSONAL_DATA>
<EMPLID>AA0001</EMPLID>
<NAME>Adams<NAME>
</PERSONAL_DATA>
...
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Hi Nail, This is my first reply in this forum and I hope it be beneficial. I think it is not possible to apply polymorphism on the Type of the generic collection; the generic Type has to be the same. so this I think it will work List> list = new LinkedList> |
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Until you find out it's going to be difficult, so you'll need to analyze first. Using getClass(), instanceof and casting you can already find out a lot. A recursive call may be quite useful: public static void analyze(Object object, String indent) { if (object == null) { System.out.println(indent + "null"); return; } Class cls = object.getClass(); System.out.println(indent + cls.getName()); if (object ... |
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For a binary search to work, the List must be sorted before use, and the searching must use the same ordering as the sorting. What > means is that whatever type you have in the List must be Comparable, which means it implements the Comparable interface. But Comparable takes a type itself, so it must be comparable ... |
Hello, I have a collection of projects. A project contains a projectname, customername, adress, contractnr, startdate, duration, ...... The intention is to show them into a calendarview. There are about 50 projects a year. The projects are serialized. Do i have to put them into an arraylist, hashset or a map ? Kind regards |
import java.util.*; public class FishFarm { private HashMap findFish; public FishFarm() { Map> findFish = new HashMap>(); } public void fish() { HashMap findFish = new HashMap>(); } public void addFish() { List temp; temp = new ArrayList(); temp.add(new Fish("Shark","Carnavour", "Salt Water",20)); this.findFish.put("Shark", temp); this.findFish.get("Shark").add(new Fish("Shark","Carnavour", "Salt Water",20)); } } |
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/** * Prints the order of the driver information based * on a boolean value. */ public void printLogsByDrivers(boolean ordered) { if(ordered) { // Get the set of entries in the map. Set> set = driverDist.entrySet(); // Create a list entries in the map by decreasing from the set. List> entries = new ArrayList(driverDist.entrySet()); Map.Entry entry = entries.get(0); ... |
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In your for loop, look up the value using the map's get method. As an alternative, iterate over the map's entry set, for each entry, check if the key is in the list, and if so, display the key and the value. I doubt that this apporoach is advantageous over the first one, though. |
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It gave me the below output:- List of drives:- 1 Name:" " Path: "C:\" 2 Name:" " Path: "C:\" 3 Name:" " Path: "C:\" 4 Name:" " Path: "C:\" 5 Name:" " Path: "C:\" 6 Name:" " Path: "C:\" 7 Name:" " Path: "C:\" On my mahcine i have a C:\ and 5 mapped network drives which are currently active and ... |