hashmap

could not persist data of format map<string,Arraylist> in jdo

由 一个人想着一个人 提交于 2020-01-06 08:10:31
问题 iam trying to persist a Hashmap data in JDO. initially i created a Hashmap like Map<Integer,String> dat=new HashMap<Integer,String>(); and this worked perfectly and i was able to save data., but when i tried Map<Integer, ArrayList<String>> dat=new HashMap<Integer,ArrayList<String>>(); i got an error like this data: java.util.ArrayList is not a supported property type. am i using a non supported data type ?? is there a better alternative ?? i am just doing this for learning purpose ...so your

LinkedCaseInsensitive map casting issue with HashMaps with Spring higher version

由 ≯℡__Kan透↙ 提交于 2020-01-06 07:17:28
问题 The LinkedCaseInsensitiveMap is part of the Spring Framework and extends the LinkedHashMap The hierarchy goes like this: java.lang.Object java.util.AbstractMap java.util.HashMap java.util.LinkedHashMap org.springframework.util.LinkedCaseInsensitiveMap For information refer : https://docs.spring.io/spring/docs/3.2.4.RELEASE_to_4.0.0.M3/Spring%20Framework%203.2.4.RELEASE/org/springframework/util/LinkedCaseInsensitiveMap.html Now I have this code : List<HashMap<String, String>> l_lstResult =

Default hash values

由 白昼怎懂夜的黑 提交于 2020-01-06 06:58:26
问题 I'd like to have a hash with params members with defaults default values: var defaults = { item1: "def1", item2: "def2" }; var params = { item2: "param2", item3: "param3" }; var result = // some clever code here... console.log(result); // { item1: "def1", item2: "param2", item3: "param3" }; The most clever code I can figure out is to iterate defaults members and add them into params if they are missing there. I wonder if there is some native solution instead of writing own code? Prototyping

Error “Cannot use object of type stdClass as array” when accessing a clearly existing, integer type data from Laravel Database query result

由 ≡放荡痞女 提交于 2020-01-06 04:50:15
问题 I got my data from Laravel database query command: $group = DB::table('groups')->where("id", $group_id)->first(); When I var dump my data, I get: object(stdClass)#200 (7) { ["id"]=> int(1) ["levels_id"]=> int(1) ["title"]=> string(8) "Novice 1" ["description"]=> string(11) "Lorem Ipsum" ["max_question_display"]=> int(5) ["created_at"]=> NULL ["updated_at"]=> NULL } I want to access the max_question_display . But when I do: var_dump($group["max_question_display"]); PHP returns error Cannot use

Getting value from Nested HashMap into another Map

由 自古美人都是妖i 提交于 2020-01-06 03:14:08
问题 Hi, I wanted to store key and value of a nested Map that looks like this: Map<ArrayList <String>, Map<String, Integer>> NestedMap = new HashMap<ArrayList<String>, Map<String, Integer>(); into another variable let say getKeyFromInsideMap and getValueFromInsideMap. So it would be the values of the inside Map String and Integer that am interested in accessing. How do I this in a code? I tried several examples here in the forum but I don't know how the syntax would look like. Could you please

Unordered map for unique keys and hashing

由 ╄→尐↘猪︶ㄣ 提交于 2020-01-05 09:15:21
问题 I am working in a library in which some elements, that do not matter here, must be identified with a name (i.e. values are associated to names). Names are strings for the user, whatever their internal representation is, and should behave transparently. Names are constant and initialized with strings literals. They are known at compile-time. Two names that were initialized with different strings must compare different , whatever their internal representation is. Names may be of arbitrary

Unordered map for unique keys and hashing

由 北慕城南 提交于 2020-01-05 09:15:12
问题 I am working in a library in which some elements, that do not matter here, must be identified with a name (i.e. values are associated to names). Names are strings for the user, whatever their internal representation is, and should behave transparently. Names are constant and initialized with strings literals. They are known at compile-time. Two names that were initialized with different strings must compare different , whatever their internal representation is. Names may be of arbitrary

Java: Using Classes as a value in hashmap [duplicate]

由 北战南征 提交于 2020-01-05 08:53:25
问题 This question already has answers here : Casting to a Class which is determined at run-time (2 answers) Closed 6 years ago . I'm trying to use custom Class as a value in a Map<String, Class<?>> . Following are relevant parts of code: Following is declaration and initialization of Map in main() : public static Map<String, Class<?>> mapQuery2ResponseType = new HashMap<String, Class<?>>(); static { mapQuery2ResponseType.put("string1", CustomClass1.class); mapQuery2ResponseType.put("string2",

How to iterate nested map in velocity template?

由 会有一股神秘感。 提交于 2020-01-05 07:16:58
问题 How to iterate nested map in velocity template? I have HashMap<String, HashMap<String, HashMap<String, List<MealPlanGroup>>>> termPlans=new HashMap<String, HashMap<String, HashMap<String, List<MealPlanGroup>>>>(); this map i filled data in java and render to html page but not able to iterate on html page 回答1: Given that you have that scary variable bound to termPlans variable inside a template, you could do the following: #foreach( $level1 in $termPlans ) <!-- Iterating over the values of the

java之map的基本介绍

由 若如初见. 提交于 2020-01-05 04:45:58
map简介 在讲解Map排序之前，我们先来稍微了解下map。map是键值对的集合接口，它的实现类主要包括：HashMap,TreeMap,Hashtable以及LinkedHashMap等。其中这四者的区别如下（简单介绍）： HashMap 我们最常用的Map，它根据key的HashCode 值来存储数据,根据key可以直接获取它的Value，同时它具有很快的访问速度。HashMap最多只允许一条记录的key值为Null(多条会覆盖);允许多条记录的Value为 Null。非同步的。 TreeMap 能够把它保存的记录根据key排序,默认是按升序排序，也可以指定排序的比较器，当用Iterator 遍历TreeMap时，得到的记录是排过序的。TreeMap不允许key的值为null。非同步的。 Hashtable 与 HashMap类似,不同的是:key和value的值均不允许为null;它支持线程的同步，即任一时刻只有一个线程能写Hashtable,因此也导致了Hashtale在写入时会比较慢。 LinkedHashMap 保存了记录的插入顺序，在用Iterator遍历LinkedHashMap时，先得到的记录肯定是先插入的.在遍历的时候会比HashMap慢。key和value均允许为空，非同步的 map的排序 TreeMap的排序 TreeMap默认是升序的
订阅 hashmap