arraylist | 易学教程

GroovySql: How to update a table with Arraylist variables

阅读更多关于 GroovySql: How to update a table with Arraylist variables

问题 I am trying to write an GroovySQL script that will have three different Arraylist variable. A1[1,2,3],A2[4,5,6],A3[7,8,9]. I want to update the table such that three rows of the three columns of the table are updates as Data should be (in row wise) R1: 1,4,7 R2: 2,5,8 R3: 3,6,9 def sql = Sql.newInstance("jdbc:mysql://localhost:3306/words", "Test", "test", "com.mysql.jdbc.Driver") def nid = 1 def newupdate = "hello world" sql.executeUpdate("update word set spelling = ? where word_id = ?", [

Full content is not written into a file

阅读更多关于 Full content is not written into a file

问题 I've the below set of data in my text file. 10 100 3 5 75 25 200 7 150 24 79 50 88 345 3 8 8 2 1 9 4 4 56 90 3 542 100 230 863 916 585 981 404 316 785 88 12 70 435 384 778 887 755 740 337 86 92 325 422 815 650 920 125 277 336 221 847 168 23 677 61 400 136 874 363 394 199 863 997 794 587 124 321 212 957 764 173 314 422 927 783 930 282 306 506 44 926 691 568 68 730 933 737 531 180 414 751 28 546 60 371 493 370 527 387 43 541 13 457 328 227 652 365 430 803 59 858 538 427 583 368 375 173 809 896

Calling Stored Procedure With List Parameter

阅读更多关于 Calling Stored Procedure With List Parameter

问题 I am unable to figure out how to send a list as a parameter to SQL Server Stored Procedure using myBatis call sp(List<Object>) I have a stored procedure inside a SQL Server(2012) which takes a parameter of type list. CREATE TypeTable of Table ( @FKId IN @FKId INT @FKId INT @FKId INT @FKId INT @userName VARCHAR ) My Stored Procedure call ALTER PROCEDURE SP(@TypeTableList Typetable READONLY ) AS BEGIN /* My DB Operations To Enter New Records and Thier Child Records */ END MyMapper <select id=

ArrayList vs LinkedList for both Random-Access & Additions-Removals

阅读更多关于 ArrayList vs LinkedList for both Random-Access & Additions-Removals

问题 I am well versed with pros and cons of ArrayList and LinkedList. ArrayList is preferred for random access, when additions and removals are less, and vice versa. What if I need a data structure where I need to do both random access, and need to add & remove items from the list often? Which one to choose? 回答1: These data structures are API-compatible, just benchmark/profile your code with both. Another hint: with ArrayList assume you perform N lookups and N mutations. This totals to O(N) + O(N

How to get contents of arraylist from first activity in second activity

阅读更多关于 How to get contents of arraylist from first activity in second activity

问题 All Task.java public class AllTask extends AppCompatActivity{ ArrayList<Company> companyList; Bundle extras; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.task_list); companyList=new ArrayList<>(); companyList.add(new Company("Kony Labs","10:30","Good")); companyList.add(new Company("Delloite","12:30","Very Good")); companyList.add(new Company("Accenture","14:30","Average")); companyList.add(new Company("Microsoft",

Convert List of ArrayList of Objects into Object [][]

阅读更多关于 Convert List of ArrayList of Objects into Object [][]

问题 Do anyone have an idea how to convert 2 dimension List: private List<ArrayList<Object>> data = new ArrayList<ArrayList<Object>>(); into array: Object [][] data; ? I noticed that data.asList( new Object[i][j] ); is returning only 1 dimension like T[] . Of course j dimension is always constant. 回答1: You could use a for loop and call toArray() for each inner list. Object[][] arr = new Object[data.size()][]; int i = 0; for(ArrayList<Object> list : data){ arr[i++] = list.toArray(); } With java-8,

Array inside arraylist access

阅读更多关于 Array inside arraylist access

问题 I am trying to access a variable that is stores as part of an object that is in an array. However that array is in an arraylist. How can access that variable? To make it clear, I have a car object that has speed. I placed 4 cars in an array. And that array is duplicated and put in an arraylist. public int getSpeedOfCarA (int index) {//used to access the variable speed in an array return garage [index].getSpeed (); } Now I was trying this but got stuck. public int getSpeedOfCarB(int n){

Array inside arraylist access

阅读更多关于 Array inside arraylist access

第七章：集合类

阅读更多关于第七章：集合类

7.1集合概述类可以存储任意类型的对象，并且长度可变，统称为集合。这些类都位于java.util包中。集合按照其存储结构可以分为两大类，即单列集合Collection和双列集合Map,这两种集合的特点具体如下。 Collection：单列集合类的根接口，用于存储一系列符合某种规则的元素，它有两个重要的子接口，分别是list和set。其中，list的特点是元素有序、元素可重复。set的特点是元素无序并且不可重复。list接口的主要实现类有ArrayList和LinkedList，set接口的主要实现类有HashSet和TreeSet。 Map：双列集合类的根接口，用于存储具有键(Key)、值(Value)映射关系的元素，每个元素都包含一对键值，在使用Map集合时可以通过指定的Key找到对应的value，例如根据一个学生的学号就可以找到对应的学生。Map接口的主要实现类有HashMap和TreeMap。 7.2 Collection接口 Collection是所有单列集合的父接口。 Collection接口的方法 Boolean add(Object o)：向集合中添加一个元素 Boolean addAll(Collection c)：将指定Collection中的所有元素添加到该集合中 Void clear()：删除该集合中的所有元素 Boolean remove(Object

Removing items from ArrayList upon collision (Java)?

阅读更多关于 Removing items from ArrayList upon collision (Java)?

问题 As a preface, I have searched the forums but found nothing relating to my specific situation. I just started learning Java about a week ago, and this is my first foray into object oriented programming. I'm building a basic game (think somewhat like Space Invaders when it comes to mechanics). I have a "Projectile" class, a "FallingThings" class (which is the parent class to the classes I have for objects falling down (Money, Friend, Enemy)). Each projectile that is shot is stored in an