Sort a treemap/hashmap by values

I'm writing a really simple program that creates a treemap and writes it line by line to a text file. I want it to be ordered by the values asociated with the keys, not by the keys themselves.
The map simply has strings for keys, the value with each one is the number of times that string appears in the input text file.
I've looked at the constructor treemap(Comparator c), but didn't really see how I could use it. Is there a simple way to get the text file sorted by values, not the keys?
Thanks!

Do you really need a SortedMap to do this? Is there any point when you really need the data sorted by the String keys?
Probably easier, once you have the collection of String/frequency pairs, just to dump that into a List and sort the List using a comparator that looks at the frequency primarily.

Similar Messages

Sorting the TreeMap

I am trying to sort a TreeMap based on Values like this:-
public class SortedValueTest
public static void main( String[] args )
Map map = new TreeMap();
map.put( "field1", new Integer( 0 ) );
map.put( "field2", new Integer( 2 ) );
map.put( "field3", new Integer( 2 ) );
map.put( "field4", new Integer( 0 ) );
Set set = new TreeSet(
new Comparator()
public int compare( Object o1, Object o2 )
Map.Entry e1 = (Map.Entry)o1;
Map.Entry e2 = (Map.Entry)o2;
Integer d1 = (Integer)e1.getValue();
Integer d2 = (Integer)e2.getValue();
return d1.compareTo( d2 );
set.addAll( map.entrySet() );
for ( Iterator iter = set.iterator(); iter.hasNext(); )
Map.Entry entry = (Map.Entry)iter.next();
System.out.println( entry.getKey() + " = " + entry.getValue() );
The output obtained is like this:-
field1 = 0
field2 = 2
But the required output should not omit the duplicate items.
So the above solution based on TreeSet does not seems to be applicable.
Is there any alternative way to solve this problem?
Thanks in Advance.

SOLVED!!!
import java.io.IOException;
import java.util.*;
* Created by IntelliJ IDEA.
* User: ponmanadiyilv
* Date: 06-Mar-2006
* Time: 11:46:29
* To change this template use File | Settings | File Templates.
public class GoodSort {
public static void main(String[] args) throws Exception {
Map m = new HashMap();
m.put ("field1", new Integer(12));
m.put ("field2", new Integer(2));
m.put ("field3", new Integer(30));
m.put ("field4", new Integer(5555));
m.put ("field5", new Integer(0));
m.put ("field6", new Integer(5555));
ArrayList outputList = sortMap(m);
int count = 0;
count = outputList.size();
while(count > 0) {
Map.Entry entry = (Map.Entry) outputList.get(--count);
System.out.print("Key:" + entry.getKey());
System.out.println("\tValue:" + entry.getValue());
* This method will use Arrays.sort for sorting Map
* @param map
* @return outputList of Map.Entries
public static ArrayList sortMap(Map map) {
ArrayList outputList = null;
int count = 0;
Set set = null;
Map.Entry[] entries = null;
// Logic:
// get a set from Map
// Build a Map.Entry[] from set
// Sort the list using Arrays.sort
// Add the sorted Map.Entries into arrayList and return
set = (Set) map.entrySet();
Iterator iterator = set.iterator();
entries = new Map.Entry[set.size()];
while(iterator.hasNext()) {
entries[count++] = (Map.Entry) iterator.next();
// Sort the entries with your own comparator for the values:
Arrays.sort(entries, new Comparator() {
public int compareTo(Object lhs, Object rhs) {
Map.Entry le = (Map.Entry)lhs;
Map.Entry re = (Map.Entry)rhs;
return ((Comparable)le.getValue()).compareTo((Comparable)re.getValue());
public int compare(Object lhs, Object rhs) {
Map.Entry le = (Map.Entry)lhs;
Map.Entry re = (Map.Entry)rhs;
return ((Comparable)le.getValue()).compareTo((Comparable)re.getValue());
outputList = new ArrayList();
for(int i = 0; i < entries.length; i++) {
outputList.add(entries);
return outputList;
}//End of sortMap

Sorting a HashMap by value

Hi all,
I have a hashMap that I need to sort into descending order by value w/out losing its key.
Example Hash:
301 | 12
302 | 48
303 | 10
304 | 20
Desired Results:
302 | 48
304 | 20
301 | 12
303 | 20
I have searched the forums and found some similar situations but nothing exactly like what I am trying to do.
I started out w/ this:
public void sort(HashMap hash)
List sortedList= new ArrayList(hash.values());
Collections.sort(sortedList);
However I lose my key & the arraylist is sorted ascending...
Any help would be appreciated!

You might extract the entry set, convert that to an array and use the static sort method of java.util.Arrays that accepts a Comparator. Implement a Comparator that looks into the entries (which are instances of Map.Entry that contain both key and value) and compares the values for whatever sorting order you want to establish.
You might then iterate over the sorted array and place the values back in a HashMap to regain access via keys. Or maybe you just store Integer instances there, giving the position of the corresponding entry in the array, from where you find the values or keys - whatever you need on each access.
Or you place that HashMap and the array in a new class that maintains them, allows to trigger sorting when needed, and provides access via key or position (internally using the array or the map as needed).
If that class should behave exactly like a map, i.e. implement java.util.Map and ALSO provides the usual iterators and keyset, valueset and entry-collection etc... with all its related behaviors, then beware: That's a major programming task!
Look at the sources of java.util.HashMap if you need to do that. Else do not implement java.util.Map and just implement the functionality that you really need at that point.

Sort ArrayList of HashMaps

Hello all
I have Arraylist that contains HashMaps
how can I sort the ArrayList by some value of HashMaps?
e.g. I have following HashMaps that are put inside a list and need to sort them by there value
ArrayList<HashMap> al = new ArrayList<HashMap>();
HashMap map1 = new HashMap();
map1.add( new Integer( 2 ), "two" );
map1.add( new Integer( 4 ), "four" );
HashMap map2 = new HashMap();
map2.add( new Integer( 22 ), "two2" );
map2.add( new Integer( 42 ), "four2" );
HashMap map3 = new HashMap();
map3.add( new Integer( 23 ), "two" );
map3.add( new Integer( 43 ), "four" );
al.add(map1);
al.add(map2);
al.add(map3);Thanks

Create a Comparator<HashMap> and pass that to Collections.sort. Write the comparator to use whatever rules you need to determine whether a map is "less than" another.
http://java.sun.com/javase/6/docs/api/java/util/Comparator.html
http://java.sun.com/javase/6/docs/api/java/util/Collections.html#sort(java.util.List, java.util.Comparator)
http://java.sun.com/docs/books/tutorial/collections/interfaces/order.html
http://www.javaworld.com/javaworld/jw-12-2002/jw-1227-sort.html

Custom Sorting in TreeMap.

Can I sort the contents of TreeMap according to values.
As default TreeMap is sorted according to Keys. But I want to sort it according to values. Can I met this using comparator?
Thanks in advance for your help.

no, you cannot. besides sorting, the comparator is used by the treemap to locate keys/values given an arbitrary key. if you sorted the map based on the values, you would never be able to find anything in it by key.

Sorting based on a specific value in Columns

Hi All,
Crystal 2008 version I have. And we are connecting to BW queries as source.
In a crosstab, I want to sort my row values based on a column value.
For example, in rows I have an element with three values . In column I have only one element(month), with couple of month values. My requirement is to sort rows based on a specific month (Mar'09 for example).
.....................Jan'09......Feb'09.....Mar'09
ABC...............10.............323...........33....
XYZ...............32..............33............11....
FGH...............5................34.............55...
But when I try to sort based on the Month, I can not select a specific value(mar'09). And it sorts based on the total value (sum of all months).
How can I achieve this problem?
Thanks
Ozan

For {Sort Value}, if you wanted to sort on the Jan column, then substitute the field name that your example shows as 10 in row ABC. For {row value}, substitute the field name that is used in the first column (ABC in the example).
In other words, take the value that you want to sort on, and put it in front of the value currently displaying as the row header. Then, sort on the results.
The purpose of the "000000000.00" is to make the length of the number, when converted to string, a consistent size. This is needed (a) so you know how many characters to strip off when displaying the row value, and (b) so the records don't sort as 1, 12, 2, 234, 235423, 25, 3, ...
HTH,
Carl

Sorting and Grouping by multi-value Choice columns - any options?

I found out the hard way that SharePoint doesn't support sorting or grouping lists by Choice columns that are set to "Allow Multiple Values." I'm stunned by this missing capability, and my project has come to a complete halt without it. It's like Microsoft only implemented hafl the feature -- you can put data in, but then you can't do anything with it. You can't even use the column in a formula in another column, so you can't parse it.
I'm not posting just to gripe though. Does anyone have any suggestions for alternatives? What do you do when you need to let people make multiple selections, and then you want to sort or group by those values? Are there any add-on products that allow this? At this point my only option seems to be to not allow multiple choices, but that's taking away a rather significant feature.
Thanks for any ideas,
Steve

Hi Paul,
Thank you for the reply and the additional questions. For my situation I want to use the multi-value choice to indicate a "belongs to" relationship, as in "this item belongs to projectA, projectB, and project C. Because there are more than 10 projects, I didn't want to create a separate Yes/No checkbox for each one.
For viewing the information, I'm looking primarily for a "group by" function. So if an item belongs to projectA, projectB, and projectC, it would appear three times, once under the grouping for each project. What I don't want is for a row that only belongs to projectA to be grouped separately from a row that belongs to both projectA and projectB. I want to see all the rows that belong to projectA grouped together, regardless of whether they also belong to other projects.
I'll look into using a grid control, but if you have any other suggestions I'll certainly listen.
Steve

How to sort HashMap by values?

?

You can create a TreeMap out of your HashMap using the values as the key. Just remember that the keys can not be duplicates.
Bosun

Sorting with TreeMap vs. quicksort

I've been sorting lists by throwing them into a TreeMap then retrieving them in order (especially for fairly evenly distributed lists of strings), thereby leveraging its binary tree characteristics.
My belief is that sorting this way takes N log N time, just as quicksort (as in Arrays.sort) does -- because adding items to a TreeMap takes log N time -- without any danger of stack overflows from recursing on a huge list as with quicksort, and fewer method calls which can get expensive.
I'm figuring that even if this way of sorting uses more memory than an in-place sort as in Arrays.sort, at least it won't overflow the stack, and will mostly be eligible for garbage collection anyway.
Could someone correct or confirm my conclusions, reasoning or assumptions? And how well do they apply to Collections.sort's merge sort?

Using a tree guarentees worst case O(n log n) for n
inserts.Amazing, my untrained intuition was correct.
As for stack problems these are unlikely to occur until
logn is at least a few thousand (think about stupidly large values of
n).I regularly need to sort lists of tends of thousands of strings.
.. its [quicksort's] gotcha is that
performance can degrade well below this approaching
O(n^2) (might be higher. I cant remember).Yes, O(n^2) for adversarial data. Does mergesort require a shallower recursion than quicksort does?
Since temporary use of the heap is rarely a concern for me, and datasets are very large, it sounds like mergesort and the TreeMap are viable contenders for preferred sorting methods. But I'm still apprehensive about mergesort's use of recursion.
Thank you, I gave you 5 duke dollars and matei 2.

Sorting and null for monetary values in a report

All,
I think this should be an easy one, and I've just missed something obvious.
I have a standard report in APEX 3.2.1 that includes a column with a monetary amount in it. I want the column to show the UK Pound sign, be sortable, and show nulls where appropriate.
The issue I have is I can't find a way to achieve all 3 in a satisfctory way. As I see it the options would be:
1) In the SQL for the report, concat the pound sign to the column required, e.g. SELECT '£'||amount FROM....
The issue is that this makes this field a CHAR field, so sorting would not sort in the same way as for a number field.
2) Use the Number format FML999...etc. in the Column Attribute.
The problem with this is that this is a multi-country database, and the default monetary unit is set to the US dollar.
3) Use the HTML expression box in the Column attribute to display £#COL#
This fulfills the pound sign and retaining the number format, but unfortunately a null value is displayed as a £ sign with no numbers. I can't think how to get it to leave that value in the report as completely blank.
As I said, I'm sure I've missed soemthing obvious. If anyone can spot how to achieve this it'd be much appreciated.
Regards,
Jon.

>
2) Use the Number format FML999...etc. in the Column Attribute.
The problem with this is that this is a multi-country database, and the default monetary unit is set to the US dollar.
>
The NLS currency symbol can be modified on the fly if you have some means of identifying user location/preference: {thread:id=990848} (ignore the last post)
However, it probably doesn't make sense to do that—£100 ≠ $100 (at least I hope not!)—unless there's some kind of conversion occurring in the report? Is there a currency stored along with the amount?
>
3) Use the HTML expression box in the Column attribute to display £#COL#
This fulfills the pound sign and retaining the number format, but unfortunately a null value is displayed as a £ sign with no numbers. I can't think how to get it to leave that value in the report as completely blank.
>
Use 2 columns, one for the amount, and one for the currency, with a switch to include or exclude the latter as necessary:
select
          ename
        , comm amount
        , nvl2(comm, '£', null) currency
from
          emp
where
          job in ('SALESMAN', 'MANAGER')
ENAME      AMOUNT                 CURRENCY
ALLEN      300                    £
WARD       500                    £
JONES
MARTIN     1400                   £
BLAKE
CLARK
TURNER     0                      £                                Then use both columns in the Amount HTML Expression:
#CURRENCY##AMOUNT#

SORTING Partner Result List with value Attributes

Hi Gurus,
I have added two value attribues in partner result list component and trying to sort the same in WEB UI, but is not working alothough I have logic in get_p and on_sort even.
Please help if anyone knows how to sort by value attributes.
Regards.

Hi Ginger,
the problem is because you have no real BOL attribute for your firstname and lastname that the values are not stored.
what you need to do is sort via an internal table.
here is how we did it:
TYPES: BEGIN OF ltyp_cp_sort,
           sort_key1           TYPE string,
           sort_key2           TYPE string,
           sort_key3           TYPE string,
           bp_partner_guid     TYPE bu_partner_guid,
           entity              TYPE REF TO cl_crm_bol_entity,
         END OF ltyp_cp_sort,
         ttyp_cp_sort     TYPE TABLE OF ltyp_cp_sort.
DATA: lt_cp_sort            TYPE ttyp_cp_sort,
        lt_cp_as_sort         TYPE ttyp_cp_sort,
        ls_cp_sort            TYPE ltyp_cp_sort,
        lr_entity             TYPE REF TO cl_crm_bol_entity,
        lv_wrapper            TYPE REF TO cl_bsp_wd_collection_wrapper,
        lv_value              TYPE string,
        lv_firstname          TYPE bu_namep_f,
        lv_lastname           TYPE bu_namep_l.
DATA: lv_bp_partner_guid    TYPE bu_partner_guid,
        lv_partner            TYPE bu_partner.
DATA: lv_archived            TYPE bu_xdele.
FIELD-SYMBOLS:
        <cp_sort>             TYPE ltyp_cp_sort.
FIELD-SYMBOLS:
        <lv_guid>             TYPE crmt_object_guid.
DATA: ls_data_person        TYPE bapibus1006_central_person,
        lo_iterator           TYPE REF TO if_bol_bo_col_iterator.
DATA: lv_number_cp          TYPE i.
Fill up a table with the value of the sort attribute, the entity and its treenode attributes
lv_wrapper = typed_context->result->get_collection_wrapper( ).
lo_iterator = lv_wrapper->get_iterator( ).
lr_entity ?= lv_wrapper->get_first( ).
WHILE lr_entity IS BOUND.
    CLEAR ls_cp_sort.
    CLEAR: lv_value,
           lv_firstname,
           lv_lastname.
    CALL METHOD lr_entity->if_bol_bo_property_access~get_property_as_value
      EXPORTING
        iv_attr_name = 'CONP_GUID'
      IMPORTING
        ev_result    = lv_bp_partner_guid.
here read the firstname and lastname of the BP again in variables
    CALL METHOD lr_entity->if_bol_bo_property_access~get_property_as_value
      EXPORTING
        iv_attr_name = 'ZFIRSTNAME'
      IMPORTING
        ev_result    = ls_cp_sort-sort_key1.
    CALL METHOD lr_entity->if_bol_bo_property_access~get_property_as_value
      EXPORTING
        iv_attr_name = 'ZLASTNAME'
      IMPORTING
        ev_result    = ls_cp_sort-sort_key2.
    TRANSLATE ls_cp_sort-sort_key1 TO UPPER CASE.
    TRANSLATE ls_cp_sort-sort_key2 TO UPPER CASE.
    ls_cp_sort-bp_partner_guid = lv_bp_partner_guid.
    ls_cp_sort-entity          ?= lr_entity.
    INSERT ls_cp_sort INTO TABLE lt_cp_sort.
    lr_entity ?= lv_wrapper->get_next( ).
ENDWHILE.
lv_wrapper->clear( ).
Now you are sorting the way the user wants to sort is, so change this code according to your needs and the users input..
SORT lt_cp_sort BY sort_key1 sort_key2.
UNASSIGN <cp_sort>.
After having sorted the list, add it back to the collection wrapper...
LOOP AT lt_cp_sort ASSIGNING <cp_sort>.
    lv_wrapper->add( <cp_sort>-entity ).
ENDLOOP.
Hope this helps a bit...
KR,
Micha

Sort on an unknown variable value

Can anyone tell me how to sort a report whether it be EVDRE or EVGTS on a derived value..
i.e.
Actual_Turnover, Budget_Turnover, Turnover_Variance
*1000000, 1500000, -500000
I want to sort on the variance without having it stored in the application as a member.
The problem I have is that I am using 4.2 sp3 which is pre the evdre builder.

As you noted in 4.2 sp3, sortcol and sort range are not part of the EVDRE. You have two options, one is to use an EVENE fuction to sort the memberset during the query using MDX or you can return an EVDRE or EVEXP expansion and use an excel macro to sort. The first option requires MDX knowledge and may decrease performance depending on the size of the resultset but would be returned sorted using built in webexcel refresh. The second option would require a button (with refresh and sort macro code) and results would only be sorted when the user refreshes through the button and not the toolbar refresh. Remember when sorting with a macro to select the entire data range and rowkey range.

Sorting array double or int value and keeping the associated identifier.

Hi,
How would I sort an array which contains a double or int value (I know how to do that) but I also want to keep the unique identifier which is associated to array element after the array has been sorted:
example:
identifier: 15STH7425042735
double: 742500.000
Thanks,
John J. Mitchell

Please define an it in form of entity first and then think of operating on structured data.
a better approach here would be please create an instances of appropriate structured data arrange them in form of a list and then apply specified logic on them
here is an example which you might think of implementing it and would more appropriate as per your stated requirements.
public class SampleBean implements Serializable{
   private String uniqueIdentifier = new String();
   private double appValue = 0.0;
   public void setUniqueIdentifier(String uniqueIdentifier){
       this.uniqueIdentifier = uniqueIdentifier;
   public String getUniqueIdentifier(){
      return this.uniqueIdentifier;
   public void setAppValue(double appValue){
          this.appValue = appValue;
   public double getAppValue(){
        return this.appValue;
}Sample Comparators:
Comparator comparator4AppValue = new Comparator(){
      public int compare(Object obj1,Object obj2){
              return Double.compare(((SampleBean)obj1).getAppValue(),((SampleBean)obj2).getAppValue());
Comparator comparator4UniqueIdentifier = new Comparator(){
      public int compare(Object obj1,Object obj2){
              return ((SampleBean)obj1).getUniqueIdentifier().compareTo( ((SampleBean)obj2).getUniqueIdentifier());
};Assuming that you have acquired an Array or List 'N' Elements of SampleBean with appropriate values.
the belows is the method of how to sort specified Array/List
In case of array
SampleBean sb[] = this.getSampleBeansArray();
// in order to sort using double value inside SampleBean array.
Arrays.sort(sb,comparator4AppValue);
// in order to sort using unique Identifier value inside SampleBean array.
Arrays.sort(sb,comparator4UniqueIdentifier);In case of a list
List sb = this.getSampleBeansList();
// in order to sort using double value inside SampleBean array.
Collections.sort(sb,comparator4AppValue);
// in order to sort using unique Identifier value inside SampleBean array.
Collections.sort(sb,comparator4UniqueIdentifier);Hope this might give you some idea of how to go about.:)
REGARDS,
RaHuL

Sorting members within Currency and Value Dimension

In HFM 9.3.1, how do you alphabetize the currencies within the value dimension? I tried sorting the members within the Currency dimension (because it is linked to the value dimension) and then loading the metadata to hfm as a replace. This works for Account and Entity members, however the currency dimension does not have a hierarchy (tree-structure) section in the metadata, so it does not work.
Any advice or solution would be helpful.
Thanks!

I have added a new currency in HFM 9.3.1. I added it to the metadata in alphabetical order, and it is in alphabetical order when creating a grid or extracting the metadata, yet it is showing up at the top of the [Currencies] system member list availalbe in Custom1 and Custom2, and not in alphabetical order here.
How can I resort this [Currencies} member list?

Why h:dataTable can have hashmap as value

I have a question about the book of core java sever faces. It's in chapter 12 and the title is how do i generate a popup window. page 591.
The book uses <h:dataTable value="#{bb.states[param.country]}" var="state">
But bb.states is a hashmap in backing bean bb. How can it be used as array.
Actually value attribute of <h:dataTable> has to be one of 4 types (array, list, Result, ResultSet).
param.country is the url parameter, it could be USA or Canada.
The book says, "the sates property of the backing bean bb yields a map whose index is the country name"
But hashmap doesn't have index. Could you please help?
Thanks,
Jie
the BackingBean.java is listed below:
package com.corejsf;
import java.util.HashMap;
import java.util.Map;
public class BackingBean {
private String country = "USA";
private String state = "";
private static Map states;
// PROPERTY: country
public String getCountry() { return country; }
public void setCountry(String newValue) { country = newValue; }
// PROPERTY: state
public String getState() { return state; }
public void setState(String newValue) { state = newValue; }
public Map getStates() { return states; }
public String[] getStatesForCountry() { return (String[]) states.get(country); }
static {
states = new HashMap();
states.put("USA",
new String[] {
"Alabama", "Alaska", "Arizona", "Arkansas", "California",
"Colorado", "Connecticut", "Delaware", "Florida", "Georgia",
"Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas",
"Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts",
"Michigan", "Minnesota", "Mississippi", "Missouri", "Montana",
"Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico",
"New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma",
"Oregon", "Pennsylvania", "Rhode Island", "South Carolina",
"South Dakota", "Tennessee", "Texas", "Utah", "Vermont",
"Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"
states.put("Canada",
new String[] {
"Alberta", "British Columbia", "Manitoba", "New Brunswick",
"Newfoundland and Labrador", "Northwest Territories",
"Nova Scotia", "Nunavut", "Ontario", "Prince Edward Island",
"Quebec", "Saskatchewan", "Yukon"

The book uses <h:dataTable
value="#{bb.states[param.country]}" var="state">
But bb.states is a hashmap in backing bean bb. How can
it be used as array.
Actually value attribute of <h:dataTable> has to be
one of 4 types (array, list, Result, ResultSet).The value of that expression is the String[] of states.
Notice in your code, you are populating the states Hashmap with String keys and String[] values. The above expression translates to java as:
// grab bb's states property which is a map
Map statesMap = bb.getStates();
// our actual value from the expression is 'states'
String[] states = (String[]) statesMap.get("USA");The DataTable will iterate over the String[] of 'states', which again, is the value of the expression #{bb.states[param.country]} and one of the 4 types you mentioned above.

Sort a treemap/hashmap by values

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