List « string « Java Data Type Q&A

1. Best way to concatenate List of String objects?

I am thinking of doing this way:

    List sList = new ArrayList();

    // Add elements.

    if (sList != null)

2. What's the most elegant way to concatenate a list of values with delimiter in Java?

I have never found a neat(er) way of doing the following. Say I have a list/array of strings.

and I want to concatenate them into a single string delimited by a comma ...

3. Efficient intersection of two List in Java?

Question is simple: I have two List

List<String> columnsOld = DBUtils.GetColumns(db, TableName);
List<String> columnsNew = DBUtils.GetColumns(db, TableName);
And I need to get the intersection of these. Is there a quick way to achieve this?

4. Is there a utility method to separate a list by given string?

Is there something like the following in Apache Common Lang or Spring Utils or do you write your own Util method for this?

List<String> list = new ArrayList<String>();

String enumeratedList = Util.enumerate(list, ", ...

5. Converting List to String[] in Java

How do I convert a list into an array? The following code returns an error.

public static void main(String[] args) {
    List<String> strlist = new ArrayList<String>();

6. How to convert comma delimited String to List of T in Core Java

"first time long time" as they say on the radio talk shows... I'm trying to parse a delimited property into a List. Simple enough, but for some reason I can't figure ...

7. Best way to build a delimited string from a list in java

I have a list of objects, and each object has a string property. For example, I have a List<Person> and each Person has a firstName property. I want to build a ...

8. Saving List of Strings in Java

am having problem in Saving some data in my Java code. I have like three different methods which do some respective tasks. Am calling these methods using Hessian from Php client. ...

9. Join String list elements with a delimiter in one step

Is there a function like join that returns List's data as a string of all the elements, joined by delimiter provided?

 List<String> join; ....
 String join = list.join('+");
 // join == "Elem ...

10. Why does my profanity filter not work?

List<String> cursewords = new ArrayList<String>();
cursewords.add("darn it");
cursewords.add("gee whiz");

String text = " Golly ";

if (cursewords.contains(text.trim().toLowerCase())  {
    System.out.println("found curse:" + text);
Is there a better way to do this? My filter is ...

11. Java - Optimize finding a string in a list

I have an ArrayList of objects where each object contains a string 'word' and a date. I need to check to see if the date has passed for a list of ...

12. seperate a list of input in string

i have this kind of input in string david=michael,sarah,tina,justin david is a father and michael,sarah,tina and justin are his children.i want to make an array name michael and inside the array are ...

13. How do you list the string that been internalized in a jvm?

Possible Duplicate:
Java - tell if a String is interned?
I would like to have a list of the string that have been internalized by a ...

14. Convert List to delimited String

Possible Duplicate:
Java: convert List<String> to a join()d string
Having this:
List<String> elementNames = Arrays.asList("h1", "h2", "h3", "h4", "h5", "h6");
What is an elegant way to get String ...

15. Changing list of NAMES TYPED IN CAPITALS to Names Typed In Capitals with Java

Lets say I have file with sever hundred lines of text all in capital letters. How should I go about changing the words on each line to lower case with only the ...

16. Load List in Java from its String representation?

I know this can easily be done by writing a function, however, I was wondering if there was a quick and convenient way to load a List in Java from its ...

17. Strings copied continuously despite having reinitialized for every different object

private List<String> longStr = new java.util.ArrayList<String>();
private List aList = null;
private String [] noRow = null;
private static int arrayCtr = 0;

try {
CSVReader reader1 = new CSVReader(new   FileReader(inputFilePath),';');

18. Swt table getData() to string list

I have populated swt Table and it displays it OK, but now I want to get data from swt Table to Is there any solution to get data to array or ...

19. Adding values in List dynamically

Every time a new String is generated but the List is having null value for it.

<h:dataTable value="#{add.periods}" var="prd">
        <h:column><h:inputText value="#{prd}"  /></h:column>

20. Handling large String lists in java

I've got a task, where I've got to go through several billion string lines and check, whether each of those is unique. All the lines themselves cannot be accommodated within the ...

21. Is there an existing Java utility method that can join a list of Strings on "," and "and"?

I'm looking for something to augment the function of the apache commons join() function, basically that will do what makePrettyList() does

public String makePrettyList(List<String> items) {
    String list = ...

22. Searching a word within a list, then taking all the strings between two points in the list

I have a huge list of names, I need to search for a word or number within this list and then take out all the strings in a seperate list. The ...

23. How to represent CNF (a ? ¬b ? c) ? (¬a ? d) as list or string in JAVA

For example (a ? ¬b ? c) ? (¬a ? d) to "(a !b c) (!a d)" or ((a (not b) c) ((not a) d)) I may ...

24. Joining a List in java with commas and and

Given a list

List<String> l = new ArrayList<String>();
I have a method
String join(List<String> messages) {
        if (messages.isEmpty()) return "";

25. join list of strings

26. is object a list of string or only a string?

you can always use the Collections.checkedMap(...) method. This will give you runtime type safety. This way the exception will be thrown when code attempts to add something to the map that isn't allowed (i.e. a String when you want a List ;) instead of when you want to get it out of the Map. [ October 23, 2008: Message edited by: ...

27. Converting a string into list .

28. Convert List to comma delimited string

I'm converting some code to use some of the new features in Java 1.5. The old code looks something like this: List myList = new ArrayList(); // Add items to List String newString = ""; for (Iterator it = myList.iterator() ; it.hasNext() ; ){ newString +=; if (it.hasNext()) { newString += ", "; } } Is there a similar way ...

29. List to String

Hi I am stuck in a palce where the values are in a List and i have to save this value into a string I tried list.toString(); //not give the string i am looking 4 means it includes hashcode also (String) list.get(index) //gives me a class cast exception... Any other way out to solve this problemo... Kaustubh

31. Strings in a List

A String is immutable, and a List contains references to its contents. Any amount of fudging around won't change the String referenced from the List. The only valid approach will be to remove the string form the list, and add the parsed string in its place (or at the end if order isn't an issue).

32. how to get filtered values from list

Hi guys, I have a requirement of applying filter on list. I am building a list say cityNamesList, which contains values like below: KOTHAPETA,PEDDAPALLE,KUPPAM,SIRCILLA,KAKINADA RURAL,PONNUR etc.. I am having a text box in the user interface side. When the user types a character in the text box, i capture that character and have to show the city names containing that character ...

33. What class functions like list of strings?

34. convert string to list

Instead of using ArrayList and List, use the proper format ArrayList, ArrayList, that sort of thing. That way you might actually find out what you are storing in the List. You have been told several times now that you are trying to cast a List (which is what list1.get(0) is returning) into a String, and that is an illegal operation.

35. string object add in list

36. convert from list to string

hi cotton m, yea i am new to java.. so i'm posting on the "NEW TO JAVA" forum my problem is, i just need to assure what i'm doing is correct i've finish my project anyway.. cotton.m u never been in my position?when u are still learning the language, ure not good at it.. and try to get help from any ...

38. Link List w/Objects (not Strings)

public Person() { name = "No name yet."; } public Person(String initialName) { name = initialName; } public void setName(String newName) { name = newName; } public String getName() { return name; } public void writeOutput() { System.out.println("Name: " + name); } public boolean sameName(Person otherPerson) { return (; } }// end of person class***********************************************8

39. List of strings

40. Find strings in a list using startsWith?

Hi I hope someone can help me with this problem. Before I start, my apologies as I am a student still trying to learn Java and have got to the murky ground of data structures.To help me better understand this I tried a sample program (which surprisingly was working fine til now ha). So I have a list of songs by ...

41. Updating elements in a List

42. How to typecast a String [] to a List ??

43. Convert String to List

44. how to convert string to list?

47. Converting List to String?

Is something wrong with it? What's it doing? I'd recommend using the code tags for your code. Makes it easier to read. Also, maybe use friendlier variable names... x, y, z... and j? Makes it ever so confusing. [ Edit ] For starters, your for-loop is overwriting any previous assignments to your z String every time it loops.

48. TypeCasting String To List

49. Parse a String[] and put the vales into a list of "beans"

I'm sorry, but you have been told any number of times why. It formates the code rather than letting the browser mash everything up against the right side or causing array indexing using the variable name i to swallow the indexing part and begin showing the rest of the post in italicised (or bold if b was the variable name) text. ...

50. Parse a String[] and put the vales into a list of "beans"

public String[] parse(String compositeString, String delimiter) { return compositeString.split(delimiter); } } import java.util.List; public final class IdValueObject { private String id; private List childrenIdList; public List getChildrenIdList() { return childrenIdList; } public void setChildrenIdList(List childrenIdList) { this.childrenIdList = childrenIdList; } public String getId() { return id; } public void setId(String id) { = id; } }

51. How i can adjust combo box drop down list width to longest string?

When i have specific width (e.g.: 400px) but very long string of text to display (e.g.: Strategic and Cooperative Action for the Conservation of Biodiversity in North America), the text is not completely showing (e.g.: Strategic and Cooperative Action for the Conservation of Bio). I am pretty sure somebody developed a method to adjust the drop down list width to longest ...

52. compressing and decompressing a string list

Try something like this : Compressing : ByteArrayOutputStream aos = new ByteArrayOutputStream(); GZIPOutputStream gos = new GZIPOutputStream(aos); byte[] ba = "the_string_to_compress".getBytes(); gos.write(ba,0,ba.length); gos.flush(); String compressed_string = aos.toString(); gos.close(); Decompressing : GZIPInputStream zin = new GZIPInputStream( new ByteArrayInputStream( compressed_string.getBytes() ) ); StringBuffer dat = new StringBuffer(); byte[] buf = new Byte[128]; for(int r; (!=-1;) dat.append( new String(buf,0,r) ); zin.close(); String org_string = ...

53. List

54. Getting strings from a list

Hi, I got a JList and everytime I select an item on the list it performs an action. What I am trying to do is get the string of the list and display it on a text field, I am using the following code to do so: public void valueChanged(ListSelectionEvent ev) { int nr; nr = stationList.getSelectedIndex(); switch (nr) { case ...

55. How can i get list elements as Strings?

56. How to identify whether it is list of any class or string?

i have a List of HashMap which contains the data form database. Also, i have prepared a map of property and column name which contains the value of property. My functionality gets the value from list of hashmap and set to the appropriate property using the map i prepared. So, if its is list of string then i traverse through list ...

57. Allow only String to List