arraylist

JSON deserialization throwing exception - Can not deserialize instance of java.util.ArrayList out of START_OBJECT token

由 ≡放荡痞女 提交于 2019-12-23 20:58:07
问题 The below is my JSON response, Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token at [Source: java.io.PushbackInputStream@bce1d9; line: 1, column: 556] (through reference chain: com.totalHours["data"]->com.totalHours["hourly_totals"]) "totalHours": { "hourly_totals": { "2013112101": { "distance": 1324, "calories": 90.0120018125, "steps": 1603, "active_time": 793, "inactive_time": 220, "longest_active

Plain ArrayList Linq c# 2 syntaxes (need a conversion)

由 ╄→гoц情女王★ 提交于 2019-12-23 20:50:53
问题 This question is purely academic for me and a spinoff of a question I answered here. Retrieve object from an arraylist with a specific element value This guy is using a plain ArrayList... I Know not the best thing to do ... filled with persons class Person { public string Name { get; set; } public string Gender { get; set; } public Person(string name, string gender) { Name = name; Gender = gender; } } personArrayList = new ArrayList(); personArrayList.Add(new Person("Koen", "Male"));

How To Access hash maps key when the key is an object

由 落花浮王杯 提交于 2019-12-23 20:10:17
问题 I cannot seem to figure out how to access the values of my hashmap What I am basically trying to do is create a hashmap with an array as one of the values like json style.. If that makes sense? So I want something like hash{key: value1, value2, value3, [number1,number2]} and be able to access it like (pseudocode:) hash.get(3).get(1) public class WebSearch { readFile.ReadFile xfile = new readFile.ReadFile("inputgraph.txt"); HashMap webSearchHash = new HashMap(); ArrayList belongsTo = new

Java第六次作业

由 天涯浪子 提交于 2019-12-23 19:29:52
（一）学习总结 1.用思维导图对本周的学习内容进行总结。 2.当程序中出现异常时，JVM会依据方法调用顺序依次查找有关的错误处理程序。可使用printStackTrace 和getMessage方法了解异常发生的情况。阅读下面的程序，说明printStackTrace方法和getMessage 方法的输出结果分别是什么？并分析异常的传播过程。 public class PrintExceptionStack { public static void main( String args[] ) { try { method1(); } catch ( Exception e ) { System.err.println( e.getMessage() + "\n" ); e.printStackTrace(); } } public static void method1() throws Exception { method2(); } public static void method2() throws Exception { method3(); } public static void method3() throws Exception { throw new Exception( "Exception thrown in method3" ); } }

issue creating a double array list

由 独自空忆成欢 提交于 2019-12-23 19:25:16
问题 Is there any reason the fallowing code would give A compile error ? Import java.util.*; public class Storageclass // class used to store the Student data { // creates the private array list needed. private ArrayList<String> nameList = new ArrayList<String>(); private ArrayList<double> GPAList = new ArrayList<double>(); private ArrayList<double> passedList = new ArrayList<double>(); } this is in a class access by a main file there is more in the class by it not part of this error. when I run

Concurrent Modification Exception in Java [duplicate]

由 ￡可爱￡侵袭症＋ 提交于 2019-12-23 19:23:51
问题 This question already has answers here : Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop (24 answers) Closed 2 years ago . I am getting the ConcurrentModificationException while executing this code. I am unable to figure out why it is happening? private void verifyBookingIfAvailable(ArrayList<Integer> list, int id) { Iterator<Integer> iterator = list.iterator(); while (iterator.hasNext()) { int value = iterator.next(); if (value == id)

contains() method is not working for Arrays.asList in java

由 不问归期 提交于 2019-12-23 18:23:23
问题 I have a string object that looks like: String color = "black, pink, blue, yellow"; Now I want to convert it into an array and find a color. Something like this: boolean check = Arrays.asList(color).contains("pink"); Which always gives false. Can anyone help me with this? 回答1: Your string variable color is not an array, so first of all you need to create array from that string variable with split(String dilemeter) method and create ArrayList from splitted string, like this: List<String>

Printing arraylist into output file?

由 。_饼干妹妹 提交于 2019-12-23 17:53:16
问题 FOLLOW UP QUESTION HERE: Java: Printing Arraylist to Output File? For some reason, it takes an extraordinary amount of time for the ArrayLists to be printed to the output file, usually 20-30 minutes. However, this only happens with the sort methods or the filterTitle or filterArtist methods (methods that concern String inputs). When I run filterRank or filterYear , it runs perfectly fine. When I print the song2 ArrayList directly from the filter methods, the only thing that is printed is [] ,

Java: java.util.ConcurrentModificationException

由 核能气质少年 提交于 2019-12-23 17:27:21
问题 I am making a 2D and currently working on shooting with bullets. The bullet is a seperate class. All the bullets are stored in an arraylist called bullets. I am trying to make it destroy itself when it is out of the side of the screen (< -16), but when I try it gives me this error. Exception in thread "main" java.util.ConcurrentModificationException at java.util.AbstractList$Itr.checkForComodification(Unknown Source) at java.util.AbstractList$Itr.next(Unknown Source) at GameCanvas

Performance when searching for missing numbers in array

由 天大地大妈咪最大 提交于 2019-12-23 16:55:58
问题 Given is a list containing all but 2 numbers between 1-20 (randomly ordered). I need to find those 2 numbers. This is the (working) program I came up with: public static void main(String[] args) { int[] x= {1,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19}; ArrayList al= new ArrayList(); Map map= new HashMap(); for(int i=0;i<x.length;i++) { map.put(x[i], x[i]); } for(int i=1;i<=20;i++) { if(map.get(i)==null) al.add(i); } for(int i=0;i<al.size();i++) { System.out.println(al.get(i)); } } I would
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