hashmap

how to write code for Json Array Inside Json Array as Category and subcategory with android

由 点点圈 提交于 2020-01-07 08:28:07
问题 My requirement is simple. i have a json pattern like below. i want to help in JSON parsing. as category and subcategory following way. category- DIY subcategory- Accessories subcategory- Garden etc.. full pattern will be like DIY Accessories Garden Tools Gifts Decorative Fathers day Valentines Day { "CategoryList": [{ "MainCategory": { "Attribute_Name": "DIY", "Attribute_Value": "125", "StockKeepingunit": null }, "SubCategory": [{ "Attribute_Name": "126", "Attribute_Value": "Accessories",

HashMap storing same values for all Keys

由 时光怂恿深爱的人放手 提交于 2020-01-07 08:27:11
问题 I want to store different values for unique coordinates.I am using integer array to store those values in HashMap to corresponding coordinates but every key maps to last calculated value. Code : import java.util.*; import java.awt.Point; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; public class Solution { @SuppressWarnings("empty-statement") public static void main(String[] args) { Scanner

How to implement nested XML structure into 2 ListViews?

由 荒凉一梦 提交于 2020-01-07 08:26:11
问题 I am trying to parse an XML file with the following structure: <groups> <group> <id>...</id> <name>...</name> <description>...</description> <actions> <action>...</action> <action>...</action> </actions> </group> <group> <id>...</id> <name>...</name> <description>...</description> <actions> <action>...</action> <action>...</action> <action>...</action> </actions> </group> <group> <id>...</id> <name>...</name> <description>...</description> <actions> <action>...</action> </actions> </group> <

issue to pass arraylist from an intent to another

由 一世执手 提交于 2020-01-07 06:58:35
问题 Before asking here, i first search how to pass an arraylist from an intent to another. Thanks to one of the post made on SO, I thought i found a way to do so. The thing is, when i try to display the elements from the arraylist of my target activity, i only get one of the numerous elements i originally have in my departure activity. To put it in clear, here is my code in my fisrt activity : HashMap map = new HashMap<String,String>(); map.put("key1","value1"); map.put("key2","value2");

failing in inserting values in maps java

由 你。 提交于 2020-01-07 05:12:36
问题 I am trying to insert values into maps in java to loop on them and do some calculations so what I am doing is to read a folder of 11k files which containing somethings like these: ps: all the files have the same structure SFrm EFrm SegAScr Phone 0 36 -158051 SIL 37 105 -644247 +NONTRANS+ 106 109 -96452 l SIL w b 110 112 -125055 w l aa i 113 115 -150550 aa w 7 i 116 118 -146662 7 aa i i 119 122 -46757 i 7 d i 123 126 -58440 d i SIL e 127 146 -90776 +MUSIC+ 147 152 -61098 t SIL u b 153 158

failing in inserting values in maps java

由 百般思念 提交于 2020-01-07 05:11:05
问题 I am trying to insert values into maps in java to loop on them and do some calculations so what I am doing is to read a folder of 11k files which containing somethings like these: ps: all the files have the same structure SFrm EFrm SegAScr Phone 0 36 -158051 SIL 37 105 -644247 +NONTRANS+ 106 109 -96452 l SIL w b 110 112 -125055 w l aa i 113 115 -150550 aa w 7 i 116 118 -146662 7 aa i i 119 122 -46757 i 7 d i 123 126 -58440 d i SIL e 127 146 -90776 +MUSIC+ 147 152 -61098 t SIL u b 153 158

All elements are replaced by last element in an arraylist of hashmap

由 痴心易碎 提交于 2020-01-07 03:10:11
问题 I have values as Question Q-id Q1 1 Q2 2 ...and so on I want to retrieve them by calling a function. So i used an arraylist of HashMaps as follows.. public ArrayList<HashMap<String,String>> getAllQuestions(Integer id) { try { HashMap<String,String> QuesList = new HashMap<String,String>(); ArrayList<HashMap<String, String>> QuestionArrayList = new ArrayList<HashMap<String, String>>(); // Select All Query String selectQuery = <some query here>; cursor = mDb.rawQuery(selectQuery, null); //

HashMap源码分析

由 帅比萌擦擦* 提交于 2020-01-07 00:19:29
HashMap 简介 HashMap 主要用来存放键值对，它基于哈希表的Map接口实现，是常用的Java集合之一。 JDK1.8 之前 HashMap 由 数组+链表 组成的，数组是 HashMap 的主体，链表则是主要为了解决哈希冲突而存在的（“拉链法”解决冲突）.JDK1.8 以后在解决哈希冲突时有了较大的变化，当链表长度大于阈值（默认为 8）时，将链表转化为红黑树（将链表转换成红黑树前会判断，如果当前数组的长度小于 64，那么会选择先进行数组扩容，而不是转换为红黑树），以减少搜索时间，具体可以参考 treeifyBin 方法。 底层数据结构分析 JDK1.8之前 JDK1.8 之前 HashMap 底层是 数组和链表 结合在一起使用也就是 链表散列。HashMap 通过 key 的 hashCode 经过扰动函数处理过后得到 hash 值，然后通过 (n - 1) & hash 判断当前元素存放的位置（这里的 n 指的是数组的长度），如果当前位置存在元素的话，就判断该元素与要存入的元素的 hash 值以及 key 是否相同，如果相同的话，直接覆盖，不相同就通过拉链法解决冲突。 所谓扰动函数指的就是 HashMap 的 hash 方法。使用 hash 方法也就是扰动函数是为了防止一些实现比较差的 hashCode() 方法 换句话说使用扰动函数之后可以减少碰撞。 JDK 1.8

HashMap源码学习笔记（一）

由 天涯浪子 提交于 2020-01-06 21:40:00
HashMap源码学习笔记（一） HashMap中的部分属性 /** * The default initial capacity - MUST be a power of two. * 默认的初始化容量 */ static final int DEFAULT_INITIAL_CAPACITY = 1 << 4; // aka 16 /** * The maximum capacity, used if a higher value is implicitly specified * by either of the constructors with arguments. * MUST be a power of two <= 1<<30. * 最大容量 */ static final int MAXIMUM_CAPACITY = 1 << 30; /** * The load factor used when none specified in constructor. * 默认的加载因子 */ static final float DEFAULT_LOAD_FACTOR = 0.75f; /** * The bin count threshold for using a tree rather than list for a * bin. Bins are converted

Get click from button on every row in listview

由 会有一股神秘感。 提交于 2020-01-06 14:05:11
问题 I generated a ListView as seen below I don't have enough rep to post images, you'll have to decipher my URL: image The blue rows in the above image are populated using HashMap : private void showListView(JSONArray rows, JSONArray totals){ final ListView list = (ListView) findViewById(R.id.historylist); ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>(); HashMap<String, String> map; String[] titles = new String[]{"recordID","date","description","num1","num2"};
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