I'm looking for a structure which hashes keys without requiring a value. When queried, it should return true if the key is found and false otherwise. I'm looking for ... |
Freemarker has two collection datatypes, lists and hashmaps
Is there a way to iterate over hashmap keys just as we do with lists?
so if i have a var with data lets say
user ...
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I'm trying to get familiar with Collections. I have a String which is my key, email address, and a Person object (firstName, lastName, telephone, email). I read in the ... |
why is this syntax not legal..? Can you throw some light on what is the design issue in not allowing HashMap to be static with declarations like this.?
static HashMap<String, ...
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Possible Duplicate:
How to Initialise a static Map in Java
How to fill HashMap in Java at initialization time, is possible something like this ?
public static ...
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My Hashmap as declared as HashMap<String, ArrayList<SortableContactList>> where SortableContactList list is a POJO class as
public class SortableContactList {
private long id;
private String displayName;
...
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I would like to know of a Map that works like a regular HashMap/Hashtable except it takes a function which returns the hashcode and performs the equality test rather than letting ... |
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I want a map indexed by two keys (a map in which you put AND retrieve values using two keys) in Java. Just to be clear, I'm looking for the following ... |
Given a list of records, I'm trying to get a count of how many records each author has written. The obvious way is to use a map, with the keys ... |
What is the Java equivalent of http://php.net/manual/en/function.hash-hmac.php ?
I need to specify both the data and the secret key to generate a SHA512 hash.
Best I've found so far is |
Sorry if my questions a bit confusing, it's a little hard to phrase. I'm wanting to implement a collection (a bit like a map but for single values rather than ... |
Hi All, Thanks a lot in advance. We are planning to use cache but we dont have any cache mechanism in the cache actually there should be some thing which provide the key, value and entry iteration that are consistent with an order of entry. For this we came up with two approaches indexing that list and LisnkedHashMap. But dont know ... |
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ok i understood we take some data put in in some cell in the map and in order to use that data we need the key for it so how do use this command equals(Object o) is it like whith objects t.equals(x); because there could be many objects in the map "t" i am puzzled how do we exctract a certain ... |
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I'm not really sure what you're asking with the whole inverted index thing. But I can tell you how I'd probably tackle the overall problem. For each file, I'd read it and create a Map with the term as the key and their frequency as the value. If you have a Map for each file it should be pretty easy to ... |
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - ... |
22. Hash Map coderanch.com |
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I am trying to use the combination rule of "n!/r!(n-r)!" but here is the pbm according to this if I wanted all the combinations for a particular number of pairs eg all two pair values ... eg 1, 2, 3, 4 the outcome would be (1,2) , (2,3) , (3,4) , (1,3) (1,4) , (2,4) but I need all possible pairs ... |
Thank you Ernest, Yes!! null check I should do..But why I did not do so means, I know that, if any key value is equal to mid, there is a value too..because those values I put in Hash map previous..Any ways, But Its good to check for null condition. I will change it. But, to get key is there any other ... |
I have a Game class,Room class and an Item class for this. The room has a hashmap and trying to put items in the room using a hashmap as well almost copying the room class. I get an error in game though when trying to access the method. In game it errors on the second line Room nextRoom = currentRoom.getExit(direction); Item ... |
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Hello the sql query is returning eighty(80) records in five columns where m_product_id cant be null , and fileds url1,url2,url3,url4 .....can be null or not. .i am having 50 urls . but in my hasp map , only 17 values are being inserted String sql = "select m_product_id,coalesce(url_picture_1,''),coalesce(url_picture_2,''),coalesce(url_picture_3,''),coalesce(url_picture_4,'')" + " from m_product where url_picture_1 is not null or " ... |
i have a hash map that stores user name and password; Map userData = new HashMap(); -this map stores a username of type string and password stoerd as hash value i can successfully add user (user name& password) i need help in implementing a getPassword(): this method must ask the user to enter username and should return the associated ... |
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Hi All, We created a custom class to act as a key for HashMap as follows : import org.apache.commons.lang.builder.HashCodeBuilder; import com.CommonUtils; public class CustomKey { private String id1 = null; private String id2 = null; private String id3 = null; private String id4 = null; private String id5 = null; public CustomKey(String id1, String id2, String id3, String id4, String id5){ ... |
Shorter Version - What are the traits of a HashMap key? Extended Version - A certain someone asked me a question for which, I frankly had no clue where to start looking for the answer! We know a HashMap is made up of key and value pairs. In most cases I've worked with key being an integer type which suffices for ... |
Hi All , I i have the data in below format: Name Age Skill Company Vass 21 Java Zylog Samy 24 PB HP Lee 18 ADF CTS Reng 16 Java Info I converted this data into java collections List like this. import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; public class HashMapDemo { public static void main(String[] args) { // ... |
Hi, I am maintaing a map of key, value pairs. The key is a POJO and the value is a list So it goes Map - HashMap While browsing an array, some elements of the array describe the pojo and the rest describe the object that go in the list So, new POJO(). setProp1(arr[0]); new POJO(). setProp2(arr[1]); new POJO(). setProp2(arr[2]);.... ... |
go through this import java.util.*; public class English { public static void main (String[] args) { SortedMap ma=new TreeMap(); char letter; for (letter = 'z'; letter>='a'; letter--) { ma.put(letter,letter); } Iterator iterator = ma.keySet().iterator(); while (iterator.hasNext()) { Object key = iterator.next(); System.out.println("key : " + key + " value :" + ma.get(key)); } } } if got idea and got as ... |
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I am currently doing an estate agency java project. I have properties and buyers both stored in two different Hash Maps. In the following method I am trying to display the number of sold houses (there is a buyer). I keep getting an error message saying: for each not applicable to expression type. Here is my code: /** * Displays the ... |
Hi all, I have following questions: 1)Is there any other way to sort a hashmap(based on key ordering) without using treemap? 2)IF there is a way to sort a hashmap without creating a new instance of treemap,so it is consume lots of time as compare to sorting it with creating a new of treemap?? Please help me to solve my puzzle. ... |
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I am trying to figure out how to use Comparator / Comparable to sort a Hash Map by value within the object. I have been searching for examples but haven't quite found what I am looking for. I'll post a generic situation below. Program asks user if they would like to sort by id number, Name or School. public ... |
/** * Return who has given book * Null if not checked out. */ public Patron whoHas(Item i) { return checkoutsMap.get(i); } /** *Uses WhoHas() method for this public boolean checkOutItem(Item i, Patron p) { if(whoHas(i)) { return null; } checkoutsMap.put(i, p); //Assign item variable to patron variable in the Hash Map } |
public class ClassUsingStaticData { public static void main(String[] args) { for(Map.Entry e : ClassWithStaticData.map.entrySet()) { System.out.format("map[%s]=%s%n", e.getKey(), e.getValue()); } } } Can you tell me that what is the meaning of Map.Entry e : which is present in the for loop.. First of all there is no method like Entry ... So kindly tell me that why you ... |
Do you realise that, in general, there may be multiple keys which map to the same value? That said there are two ways you could go: (1) If the key/value mapping is actually 1-1, use two maps where the keys of one are the values of the other and vice versa. Use one map to find values (as you illustrated), and ... |
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Explain how TreeMaps represent maps. Explain how HashMaps represent maps. What are the advantages and disadvantages of TreeMaps compared to HashMaps? When should a program use TreeMaps, and when should it use HashMaps? Maps can also be implemented using two arrays, one of which stores keys and the other of which stores values (the ith member of the value array records ... |
from what I understand : Here, this.isForceMonth => is the boolean value being referenced in your class. StringUtils.getBoolean( => getBoolean is a static method being refered from a class called StringUtils.This method takes in a String value and a boolean as a parameter, and checks for null or true, and then returns the boolean value or the default value. (String)argumentList.get("isForceMonth"),false); => ... |
So This is what i could come up with, i just created one class Dictionary , now I am able to search for the meaning of the word specified by me, and I am able to print all the words and there meanings added to the hashmap, but i am not able to figure out how to add a new word ... |
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50. Hash Map forums.oracle.com |
My while loop doesnt seem to work in a hash map, it works fine when I loop an array list. It compiles but it doesnt seem to find any employees, should I use another loop? {code public Employee find(String id) { Employee foundEmployee = null; int index = 0; boolean found = false; while(index < register.size() && !found){ Employee right = ... |
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53. Hash maps forums.oracle.comHi everyone, I would like to create a map with three different values in a map, which will be the name of an item (String), its price and the quantity (integers). But according to the java API you can only create an hash map with two values: the key, and the value. Do I have to create two different hash map? ... |
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url2----------------05_eclipse320_QSSrun_debug_arg.png url3----------------INVOICE_1.gif url4----------------inv.bmp url1--------------INVOICE_1.gif url2----------------s8.gif url3---------------- url4---------------- url1-------------- url2----------------Shipment2.jpg url3----------------INVOICE_for Pos1.gif url4---------------- url1--------------s8.gif url2----------------s6_r.gif url3----------------s6_r.gif url4----------------inv.bmp url1--------------Ok32.png url2---------------- url3----------------05_eclipse320_QSSrun_debug_arg.png url4---------------- url1-------------- url2----------------Ok32.png url3---------------- url4----------------s8.gif url1--------------s8.gif url2----------------s6_r.gif url3----------------s6_r.gif url4----------------Shipment2.jpg url1-------------- url2---------------- url3---------------- url4----------------Ok32.png url1--------------Shipment2.jpg url2---------------- url3----------------s6_r.gif url4---------------- url1--------------s8.gif url2----------------s8.gif url3----------------Shipment2.jpg url4----------------s6_r.gif url1-------------- url2---------------- url3---------------- url4----------------Ok32.png url1--------------Ok32.png url2----------------05_eclipse320_QSSrun_debug_arg.png url3---------------- url4---------------- url1--------------inv.bmp url2---------------- url3---------------- url4----------------INVOICE_for Pos1.gif url1-------------- url2----------------inv.bmp url3----------------05_eclipse320_QSSrun_debug_arg.png url4---------------- url1--------------s5_g.gif url2----------------05_eclipse320_QSSrun_debug_arg.png url3----------------s5_g.gif url4---------------- ... |
56. hash map forums.oracle.com |
Okay that was the reason why i asked OP to use LinkedHashMap as per the discussed senario. and if he is looking to Create a Map by sorting values he might have define what should happen when a null value is encountered as HashMap accepts null values & You can consider other cases too. where he might insert Objects of different ... |
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61. Hash map forums.oracle.com |
62. hash map forums.oracle.comcan anyone just help me with hash table/ im trying to call the put() method inside a if loop. so that i wanted to incriment the key value of the put() every time it enters the loop. if (condition==true) { i++; hm.put(i,"value") } first the 1 should be 1 ,then 2 etc....could anyone help me sorry if i explained it wrongly. ... |
The code you wrote above won't compile. What you're trying to do probably won't work either, although you can force it to work by violating enough Java idioms for solid code. You can violate a few less such idioms and still do the same thing, but it will still be poor design. The best solution is almost certainly to refactor your ... |
64. Hash Map forums.oracle.com |
apologies if this has already been posted, but i have a hashmap with integers in the values. what i need to do is add up all the values together and print out on the console the total. have no problems with console printing, just the adding of the values. any help would be appreciated matt |
Hello Techies, I have a drop down list which is used to select a contry name. I also contains " All " option which is used to select all countries. I am using HashMap for this drop down list for getting corresponding value. Now, my requirement is the " All " should display as the first in the drop down list. ... |
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