I have an ArrayList that I want to output completely as a String. Essentially I want to output it in order using the toString of each element separated by tabs. Is ... |
Is there a more elegant solution to convert an 'Arraylist' into a 'Arraylist<Type>'?
Current code:
ArrayList productsArrayList=getProductsList();
ArrayList<ProductListBean> productList = new ArrayList<ProductListBean>();
for (Object item : productsArrayList)
{
ProductListBean product = (ProductListBean)item;
productList.add(product);
}
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In Java I want to convert a nested List which contains at the deepest level a uniform type into an multidimensional array of that type. For example, ArrayList<ArrayList<ArrayList<ArrayList<String>>>> into String[][][][]. I've ... |
public class MyGraph<V,E> extends SparseMultigraph<V,E>{
private ArrayList<MyNode> myNodeList;
public MyNode getNode(int nodeId){
myNodeList = new ArrayList<MyNode>();
...
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This sadly doesn't work:
long[] longs = new long[]{1L};
ArrayList<Long> longArray = new ArrayList<Long>(longs);
Is there a nicer way except adding them manually?
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In Java how do you convert a ArrayList into a two dimensional array Object[][]?
From comments: I will describe you the problem with more details: an XML file includes a ... |
How do I convert an array to a list in Java?
I used the Arrays.asList() but the behavior (and signature) somehow changed from 1.4.2 to 1.5.0 and most ... |
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Is there a command in java for conversion of an ArrayList into a object array. I know how to do this copying each object from the arrayList into the object array, ... |
String text = '[["item1","item2","item3"], ["some", "item"], ["far", "out", "string"]]';
I would like to iterate over each individual ArrayList. I don't know how to turn that string into appropriate ArrayList object.
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How t convert string array list to string array in java ?
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How do I converting an ArrayList of strings into a BufferedReader? I'm open to making the ArrayList as an Input Stream instead, but I want an easy way to add strings ... |
How, in Java, do I convert an ArrayList of arrays to a two-dimensional array?
Example:
ArrayList<String[]> results = new ArrayList<String[]>();
String [] columns = {a few strings};
JTable table = new JTable(results.toArray(), columns);
I get the ... |
ArrayList<Object> list = new ArrayList<Object>();
list.add(1);
list.add("Java");
list.add(3.14);
System.out.println(list.toString());
I tried:
ArrayList<String> list2 = (String)list;
But gave me a compile Error.
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so I have this code
int[] tcc = {1,2,3};
ArrayList<Integer> tc = Arrays.asList(tcc);
but then java complains cannot convert from List<int[]> to ArrayList<Integer>
what's wrong with this
why is it List<int[]> and not List<int>
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suppose I have an arraylist of the form ArrayList<ArrayList<E>> ... what would be the most elegant way to convert this into 2 dimensional arrays
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I want to convert a List to a List so that each object on my new list includes the first element of each String[].
Do you know if this is possible to ... |
When I try to convert a double array to a Double list I got the following error:
Exception in thread "main" java.lang.ClassCastException: [D cannot be cast to java.lang.Double
Below is my ... |
I have a menu structure that outputs a list of favourite configuration items.
In the Android SDK in the Views examples there is a view example that I would like to use ... |
Here is my class Structure, and where I am getting error
class SuperClass{
//variables
}
class SubClass1 extends SuperClass{
//variables
}
class SubClass2 extends SuperClass{
//variables
}
class AClass{
List<SuperClass> list;
public AClass(boolean b){
if(b)
list = new ArrayList<SubClass1>();//getting error here
else
list = new ...
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Possible Duplicate:
How to cast from List<Double> to double[] in Java?
So far the only method I can get working is to loop through the entire ... |
In Java How do you convert an ArrayList = ['a','b','c'] to a String, the toString stores it as [a,b,c] I want to get rid of the brackets and store it as ... |
I wanted to know if it was possible to change
ArrayList<ArrayList<String>>
to String[][] in java. I do not think that the toArray() function would recurse inside its generic parameter. Any advice ... |
I have a method which converts the Object ( which is an array of primitive or strings) which i have got after invocation of a method (so its in instance of ... |
I have a CSV stored in a String:
Abc, Def, Ghi, Jkl, Mno[CR|LF]
Abc, Def, Ghi, Jkl, Mno[CR|LF]
Abc, Def, Ghi, Jkl, Mno[CR|LF]
Abc, Def, Ghi, Jkl, Mno[CR|LF]
When I open the file in Notepad++ and ... |
What is the most efficient way to convert ArrayLists with EO (Entity Object) into ArrayLists of DTO objects or ArrayLists of Ids. Please, keep in mind that every EO may consist ... |
I have a valid ArrayList object in form of java.lang.Object. i have to again convert Object to ArrayList. I tried this
Object obj2 = from some source . . ;
... |
I have a situation were I want to convert a string into an ArrayList. In my string, I can have an arbitrary number of words which I want added into an ... |
Is there any built-in method in java which allows us to convert comma separated String to some Container (e.g Array, List or Vector)? Or do i need to write custom code ... |
I am in a situation where I need to send the arraylist in the network but I need to convert it in the form of string.
Now at the destination I want ... |
How do we convert java array list of String objects to java script array?
This is what I am doing but I am looking for a better way to do it. I ... |
How can i do this ?
When i stored my fields in HashMap , i did it like simple Objects
HashMap map = new HashMap();
map.put ("Autorul",numelePrenumeleAutorului);
...
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I've been searching a solution for converting an ArrayList to a double[] array. After reading a few questions on the same issue, i figure out a solution. This is how i ... |
Possible Duplicate:
Java: How to convert List to Map
I have arrayList
ArrayList<Product> productList = new ArrayList<Product>();
productList = getProducts(); //Fetch the result from ...
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I want to know if it is safe/advisable to convert from ArrayList to Array?
I have a text file with each line a string:
1236
1233
4566
4568
....
I want to read them into array list and ... |
I have an ArrayList, each element is a String. I want to convert it into an array of String. ArrayList aL = getStringObj(); But "aL.toArray();" can only return me an array of Objects ? Of course, I can do Iterator i = aL.iterator(); String s = new String[aL.size()]; int i = 0; while(i.hasNext()) { s[i++] = i.next().toString(); } return s; where ... |
I have requirement where the user will paste these codes in the text area from the front end and I need to convert this string to Arraylist, can any body please help me with this.. ----------- 222222 333333 444444 555555 666666 777777 888888 999999 ----------- This whole numbers come as String to and need to convert to Arraylist, i treid some ... |
I can create a ArrayList and convert to String[]. How do I convert an ArrayList of String[] to String [][]? import java.util.ArrayList; public class StringArrays { public static void main(String[] args) { String[] stringArray = null; String[][] stringArrayArray = null; ArrayList stringArrayArrayList = new ArrayList(5); for (int j = 0; j < 5; j++) { ArrayList stringArrayList = new ArrayList(5); stringArrayList.add("zero"); ... |
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The version of toArray() that takes no arguments will always return an Object[]. If you want (for example) a String[], then you need to pass a String[] in as an argument. It can be any length, but if you're allocating one anyway, make it the right size and then toArray will use the one you pass in. So... String[] pNames_strArray = ... |
I want to convert ArrayList into String[] array. I tried this. List resultList=new ArrayList(); String[] str = (String[])resultList.toArray(); But i'm getting class cast Exception I tried one more. ArrayList resultList = new ArrayList(); String[] str=new String [resultList.size()]; str = (String []) resultList.toArray(str); But here i'm getting Array-store Exception Can anyone help? Regards, Praveen |
Hey, Thanks for the immedieate reply. String[] name = formattedRows.toArray(); will give us an Object Array and not a String array. However String[] name = (String[])formattedRows.toArray() will be fine. But then,how will I get the values of name now. My requirement is, My ArrayList will contain multiple rows and multiple values. like [a[1,2],b[3,4]] I need to set 1,2,3 and 4 into ... |
Originally posted by mark reyes: But I'm just wondering why my first code does not work whereas I declare my arrayList as String. I know I'm missing something here. Please help. Look at the API. toArray() returns an Object[]. This is created as an Object[], not a String[]. Therefore, you cannot cast it to String[]. toArray(T[]) returns a T[] (for whatever ... |
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Hi I have this arrayList and I need to return this as List. Is there any way I could load the data from arrayList to List my ArrayList which is called list is doing this list.add(parseResultSetRow(rs)); The method parseResultSetRow() is returning TransactionSummary type. Hope this makes sense. BTW you probably can tell i am very new at this... so please hlp. ... |
Hello, I want to convert from a HashMap, Key Value pair 1 to 1, to a HashMap where the Keys are Strings and the Values are arraylist. This way, I can have 1 key mapped to many values. This is the code: import java.util.AbstractMap; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import java.io.*; Map> map = new HashMap>(); public void ... |
I guess it's just a matter of differences in style. I like to avoid creating objects you throw away immediately. I usually go for the "toArray(new Integer[c.size()])" solution, but when that would make the line too long I will use a temp variable to increase readability. Let's drop this, shall we? In the end the code examples both you and John ... |
I have read in data from a file (which is currently in an arrayList). I need to convert this arrayList into Object (ie. - Object[][] addresses = {{"Hancock", "Bob", "01202719029", "07676101393", "1 Seseme Street, London, AB8 8AE"}}; ) because I then need to display all the data from that file in a table(DefaultTabelModel) I've got the data in an arraylist at ... |
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I have seen the discussion initiated by Dav Marzek in April 2008 on Multidimensional ArrayList to an Object[][] array. I need a solution with a re-entrant function including the ArrayList.toArray(), because the objects of my ArrayLists - are situated at various level of the multidimensional structure (up to 8) (not a square ArrayList), - are of various types : String, Boolean, ... |
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If I have an array of a class like Student[] students = initializeStudentArray(); how do I convert this "student" array into a list and make sure the objects in the list are all of type "Student" I know Arrays.asLIst() is useful. But it does not seem to ensure the objects in the list created is the same type as "Student". What's ... |
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No. Turning a String[] into an ArrayList - not a problem. Turning an ArrayList into a String[] - not a problem. But because you need to convert each String into a Long you have no other option than to use a loop. Actually, all solutions include a loop. The loop may be hidden for you (e.g. the ArrayList(Collection) constructor, List.toArray(...)) but ... |
I am writing a Client and Server instant message application. It is well on its way with multiple color support, private messaging, hacker protection, mod privileges (only me for now) that can boot people off permanently or once, etc, etc. Anyway, my point is that it is working fine and well. In my clients, I have a filter. It filters out ... |
Good morning world! I am trying to edit an array code and make it into an ArrayList code instead. I have both codes, and I am trying to finish it, but I am getting an error...... I am sorry for the long post - I will post the regular array code, then what I have, and then the errors. Long post, ... |
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import java.util.Random; public class CarLot { private static int [] tile; public CarLot() { car = new int[3]; for (int i = 0; i < 4; i++) { Random generator = new Random(); int random = generator.nextInt(9) + 1; car[i] = random; } } public Car(int [] startingCar) { tile = (startingCar; } }// end NumberTile |
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Is there any efficient and good technique to convert an ArrayList into a 2-D array? Suppose I have an ArrayList that contains objects of my defined class and then I would like to convert this ArrayList into a 2-D array. Can someone please help me out here? Your help will be really appreciated! Edited by: ti_ma on Mar 18, 2008 4:59 ... |
XML is for modeling data ArrayList is for storing data If you want to display something, you need to be more clear. But basically you can read an XML file or document and parse the data out with JAXB or whatever and you can store your data in an ArrayList. But so far you've been pretty vague about what you need ... |
hello, please i need to know how to convert types like Arraylist or multi dimensional arrays etc. Converting single types like integer is easy ( like (int)Object), but when i need to convert for example ArrayList to String[] i try: ArrayList something = new ArrayList(); String[] converted = (String[])something.toArray(); I needed to convert it to String[] because toArrayMethod returned Object[]. It ... |
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Hi all. I have a ArrayList which whose elements are instances of String.i.e say ArrayList list contains elements as Element1:"ABC" Element2: "DEF" Now I have to convert this ArrayList to array of Strings. I tried using list.toArray(), but it returns handle to array of Object. I guess the other way is to iterate thru the list using iterator and populate the ... |
gimbal2 wrote: turning the list into an array is redundant. Just Hmmm... that advise is "generally true" (ergo: generally speaking converting from a List (especially an ArrayList) to an array is just a waste of energy).... and it is definately true for the code shown... BUT I'm guessing that's just an SCCEE, and that the OP needs a String[] for some ... |
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Hi I have this arrayList and I need to return this as List. Is there any way I could load the data from arrayList to List my ArrayList which is called list is doing this list.add(parseResultSetRow(rs)); The method parseResultSetRow() is returning TransactionSummary type. Hope this makes sense. BTW you probably can tell i am very new at this... so please hlp. ... |
public ArrayList buscarEstudiante(int codigo) { Estudiante estudiante = new Estudiante(); try { String query ="SELECT codigo FROM estudiante WHERE codigo ='"codigo"'"; Connection conn= conex(); PreparedStatement ps = (PreparedStatement) conn.prepareStatement(query); ResultSet rset = ps.executeQuery(); /*System.out.println("Resultado de la consulta: "+ rset); System.out.println("Cedula: "+ rset.getInt("cedula")); System.out.println("Nombre: "+ rset.getString("nombre")); */ if (rset.next()){ System.out.println("la consulta arrojo resultados"); //System.out.println("se paso como login: "+log);//estaba comenntado //System.out.println("se paso como ... |
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HI, I have defined an Array list as follows : ArrayList input= new ArrayList(); and then populated it with integers. Now i defined an integer array as : int a[] = new int[input.size()]; a = input.toArray(a); is there something in this. It gives the following errors : cannot find symbol method toArray(int[]); Do i need to import some package?? i have ... |
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There are many ways you could convert it. 1) HashMap hashMap; List> list = new ArrayList>(hashMap.entrySet()); 2) HashMap hashMap; List list = new ArrayList(hashMap.keySet()); list.addAll(hashMap.value()); Generally it doesn't make sense to convert between a Map and a List, so if you think you need to do this I would suggest you have a re-think about your design. |
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Right. You're trying to add a two dimensional array into a variable that's only defined as a one-dimensional array. if distances1 is two dimensional, then you would need a THREE dimensional array to store a list of those arrays; does that make sense? An ArrayList(by default) is used to store a list of arrays (a one-dimensional list of (times) one-dimensional arrays ... |
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? I'm having trouble imaging this at all. Does your code compile?? Please repost with code tags. After you have pasted your code into the Message window, highlight a block of code and click the "code" button above the message window. Do this for each block of code, then press the "post" button. |
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Looks good to me. If you know the size of the Map up front, you might want to pass that as the initial size (look at the constructors of HashMap), as to avoid having to resize the Map multiple times (it's done for you, behind the scene, but it still is work that has to be done). Why do you need ... |
Hi, What would be the best solution for converting an ArrayList to and array? Currently, I use (the ArrayList contains Strings) ArrayList l = new ArrayList(); l.add(...); ... String [] v = new String [l.size()]; v = (String []) l.toArray(v); But I think this could be better or shortes. Specially, following did not work: String [] v = (String []) l.toArray(); ... |
Since it is an "old system" I doubt that is feasible. Also I believe that this was intentionally left out of the API because specifying the array type is more natural than the Class object and using the normal approach you get back the same zero-length array that you passed in if the collection is of size zero. It does look ... |
Hi, I have an ArrayList containing a list of my required parameters. in the design of a JDBC driver, I have to use a method that takes WebRowSet format of the values in the ArrayList as an argument. What is the procedure to convert a ArrayList to WebRowSet? Edited by: Junnu on Feb 23, 2011 8:51 AM |