linkedhashmap

Why doesn't LinkedHashMap provide access by index?

由 痴心易碎 提交于 2019-12-05 01:36:38
From Javadoc: Hash table and linked list implementation of the Map interface, with predictable iteration order. This implementation differs from HashMap in that it maintains a doubly-linked list running through all of its entries. If it is so, then why doesn't it provide object access like List in java, list.get(index); UPDATE I had implemented LRU Cache using LinkedHashMap. My algorithm required me to access LRU Object from the cache. That's why I required random access, but I think that will cost me bad performance, so I have changed the logic and I am accessing the LRU object just when

Static Linkedhashmap or Sharedpreference?

由 偶尔善良 提交于 2019-12-04 17:35:43
Android App with two solution for passing data between activities (No Intent Extras Please!) public class A { public static LinkedHashMap<String,String> hashStore = new LinkedHasMap<String,String>(); public void doHttp(){ //Some HTTP call and store some json value hashStore.put("data","jsonKeyValue"); } public void onDestroy(){ hashStore.remove(key);// remove data key hashStore.clear(); } } public class B { public void getHttp(){ //Some HTTP call String extra = A.hashStore.get("data"); }} // SharedPreference Call public class A{ SharedPreference hashPref ; //declaration on onCreate public void

How do I get a keyIterator for a LinkedHashMap?

由 风流意气都作罢 提交于 2019-12-04 16:52:14
问题 By looking at the source code for LinkedHashMaps from Sun, I see that there is a private class called KeyIterator, I would like to use this. How can I gain access? 回答1: You get it by calling myMap.keySet().iterator(); You shouldn't even need to know it exists; it's just an artifact of the implementation. For all you know, they could be using flying monkeys to iterate the keys; as long as they're iterated according to the spec, it doesn't matter how they do it. By the way, did you know that

Soft reference LinkedHashMap in Java?

由 ◇◆丶佛笑我妖孽 提交于 2019-12-04 13:24:03
问题 Is there softreference-based LinkedHashMap in Java? If no, has anyone got a snippet of code that I can probably reuse? I promise to reference it correctly. Thanks. 回答1: WeakHashMap doesn't preserve the insertion order. It thus cannot be considered as a direct replacement for LinkedHashMap. Moreover, the map entry is only released when the key is no longer reachable. Which may not be what you are looking for. If what you are looking for is a memory-friendly cache, here is a naive

ConcurrentModificationException with LinkedHashMap

由 帅比萌擦擦* 提交于 2019-12-04 09:09:14
问题 Not sure what is triggering a java.util.ConcurrentModificationException when I iterate over the LinkedHashMap structure in the code below. Using the Map.Entry approach works fine. Did not get a good explanation on what is triggering this from the previous posts. Any help would be appreciated. import java.util.LinkedHashMap; import java.util.Map; public class LRU { // private Map<String,Integer> m = new HashMap<String,Integer>(); // private SortedMap<String,Integer> lru_cache = Collections

GSON issue with String

由 為{幸葍}努か 提交于 2019-12-03 04:46:15
问题 String s = "m\\"+"/m\\/m/m/m/m/m"; LinkedHashMap<String, String> hm = new LinkedHashMap<>(); hm.put("test", s); System.out.println(hm+" Hash map = "+hm.toString()); Fine Output is {test=m\/m\/m/m/m/m/m} Hash map = {test=m\/m\/m/m/m/m/m} String s2 = new Gson().toJson(hm.toString()); System.out.println("Json result is "+s2); Not Fine Output is Json result is "{test\u003dm\\/m\\/m/m/m/m/m}" Is GSON going mad or is it something that I am doing wrong? What is happening to with Back Slashes and

Best structure for list of key-value (integer, string) to be shuffled

由 大城市里の小女人 提交于 2019-12-03 03:10:53
I need to implement a structure in Java that is a key-value list (of types Integer-String) and I want to shuffle it. Basically, I would like to do something like that. public LinkedHashMap<Integer, String> getQuestionOptionsMap(){ LinkedHashMap<Integer, String> shuffle = new LinkedHashMap<Integer, String> (); if (answer1 != null) shuffle.put(new Integer(1), answer1); if (answer2 != null) shuffle.put(new Integer(2), answer2); if (answer3 != null) shuffle.put(new Integer(3), answer3); if (answer4 != null) shuffle.put(new Integer(4), answer4); Collections.shuffle(shuffle); return shuffle; }

How to retrieve value from linkedhashmap using iterators in Struts2…?

由 杀马特。学长 韩版系。学妹 提交于 2019-12-02 20:01:08
问题 I have function which return LinkedHashMap in Struts2 and i just came to know that we cannot use for loop in struts2 instead we have to use Iterators, and am new to struts can any on help me to retrieve value from linkedhashmap using iterators, below is how values are lined up in hashmap: LinkedHashMap<String, ArrayList<String>> topSuppliers = new LinkedHashMap<String, ArrayList<String>>(); while(resultset.next()){ ArrayList<String> innerList = new ArrayList<String>(); String manufId =

GSON issue with String

由 随声附和 提交于 2019-12-02 17:57:40
String s = "m\\"+"/m\\/m/m/m/m/m"; LinkedHashMap<String, String> hm = new LinkedHashMap<>(); hm.put("test", s); System.out.println(hm+" Hash map = "+hm.toString()); Fine Output is {test=m\/m\/m/m/m/m/m} Hash map = {test=m\/m\/m/m/m/m/m} String s2 = new Gson().toJson(hm.toString()); System.out.println("Json result is "+s2); Not Fine Output is Json result is "{test\u003dm\\/m\\/m/m/m/m/m}" Is GSON going mad or is it something that I am doing wrong? What is happening to with Back Slashes and from where does this u003d appears? I knew that there exists a bug of this nature a long time ago but it

ConcurrentModificationException Woes [duplicate]

由 末鹿安然 提交于 2019-12-02 15:58:40
问题 This question already has answers here : Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop (24 answers) Closed 5 years ago . I have a method test(), in which I am trying to compare two LinkedHashMaps against each other and modify the contents of one of the maps by removing the key/value pair if it is found in both LHM's. I keep getting a ConcurrentModificationException when running this method. I understand WHY I am getting the exception
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