Implementing a threaded Hash Table
Hiya all,
Would like to know how to create a threaded hash table. I am making a program that should be able to take in different variables such as string and integers, and be able to store then in a Hash table. Would it be possible to retreive these variables (remove them from the hash map) in a threaded scenario?
Unlike the new collection implementations, Hashtable
is synchronized.True, but HashMap is more stable. Its performance stays roughtly the same when it's loaded with different (biased) data sets whereas Hashtable shows much more variation.
Similar Messages
-
How to Implement a Chained Hash Table with Linked Lists
I'm making a migration from C/C++ to Java, and my task is to implement a Chained Hash Table with a Linked List. My problem is to put the strings(in this case names) hashed by the table using de Division Metod (H(k)= k mod N) in to a Linked list that is handling the colisions. My table has an interface implemented(public boolean insert(), public boolean findItem(), public void remove()). Any Help is needed. Thanks for everyone in advance.
OK. you have your hash table. What you want it to do is keep key/value pairs in linked lists, so that when there is a collision, you add the key/value pair to the linked list rather than searching for free space on the table.
This means that whenever you add an item, you hash it out, check to see if there is already a linked list and if not, create one and put it in that slot. Then in either case you add the key/value pair to the linked list if the key is not already on the linked list. If it is there you have to decide whether your requirements are to give an error or allow duplicate keys or just keep or modify one or the other (old/new).
When you are searching for a key, you hash it out once again and check to see if there is a linked list at that slot. If there is one, look for the key and if it's there, return it and if not, or if there was no linked list at that slot, return an error.
You aren't clear on whether you can simply use the provided linked-list implementations in the Java Collections or whether you have to cobble the linked list yourself. In any case, it's up to you.
Is this what you're asking?
Doug -
hi, i have a CountryTable class which i want to implement as a hash table:
import java.util.*;
class CountryTable {
static int count = 0;
private HashMap table = new HashMap();
public void addEntry(Colour key, Country country) {
table.put(key, country);
count++;
public Country getCountry(Colour key) {
return (Country)table.get(key);
static int getCount() {
return count;
The object which are returned from this table is Country:
class Country {
//static variables
static int count = 0;
//instance variables
private String name;
private Colour base;
//constructor
Country(String name, Colour base) {
this.name = name;
this.base = base;
count++;
//return the number of objects created
static int getCount() {
return count;
//return the name
public String getName() {
return name;
public Colour getColour() {
return base;
The key for the has table is the class Colour, which includes a hashCode() method:
class Colour {
public int rgb;
Colour(int rgb) {
this.rgb = rgb;
public int hashCode() {
return rgb * -1;
I implement these classes in a program as follows:
CountryTable index = new CountryTable();
Colour colour1 = new Colour(-3473408);
Country argentina = new Country("Argentina", colour1);
index.addEntry(colour1, argentina);
Colour colour2 = new Colour(-131072);
Country brazil = new Country("Brazil", colour2);
index.addEntry(colour2, brazil);
Colour col = new Colour(or);
Country coun = index.getCountry(col);
System.out.println(coun.getName());
I have a list of many countries which i set up, with their relevant countires with which they are associated.
The variable 'or' contains an RGB value which has been returned elsewhere in the program. The problem that i have is that when a colour is passed into the getCountry() method, nothing is returned and a "nullPointerException" is thrown, even though a colour with which i set up a country was passed in???
Anyone got any ideas where im going wrong?
Many thanks Cathkeeping the other two files same you change the CountryTable to this
import java.util.*;
class CountryTable {
static int count = 0;
private HashMap table = new HashMap();
public void addEntry(Colour key, Country country) {
table.put(key.rgb+"" ,country.getName());
count++;
public String getCountry(Colour key) {
return (String)table.get(key.rgb+"");
static int getCount() {
return count;
public static void main (String args[]){
CountryTable index = new CountryTable();
Colour colour1 = new Colour(-3473408);
Country argentina = new Country("Argentina",colour1);
index.addEntry(colour1, argentina);
Colour colour2 = new Colour(-131072);
Country brazil = new Country("Brazil",colour2);
index.addEntry(colour2, brazil);
System.out.println(index.table);
String coun = index.getCountry(colour2);
System.out.println(coun);
}and now try -
Implementing Hash tables with chaining.
Hi, I'm in a Java data structures class right now and we have a program to do using hash tables. I've read about hash tables and chaining but does anyone know where i can find some examples of code that implement hash tables using chaining. It's all very confusing to me without seeing how it is used in a program.
To give you an idea of what we're doing, the assignment is to create a word processor that looks thru a file and adds different words to the table and also counts how many of each word there is in that file. Keep in mind I'm not asking for the code to this assignment just for some example of how coding hash tables/chaining works.Simple and probably not complete overview:
Suppose you have an array in which you will store objects.
You take an object, and find a "hash code" for it. You then restrict the hash code in to the range of your array. This gives you the index where you can store your object.
But what if another object is already present at that index?
Different solutions to this exist - such as re-hashing. One solution is "chaining". Instead of storing the object directly at the hashed index - you store a list of objects which hashed to the same location.
When you do a lookup, you first get your hash. You then look at the corresponding location in the array. If you find a list rather than the required object, you walk along the list until you find the object you are looking for.
Of course, with a small array and bad hash distribution, the performance of this solution can degrade fairly quickly.
BTW, in the real world, just use one of the ready made collections in java.util. -
The Born collection classes don't have an alternative implementation of
HashTable. Instead they are wrappers around the Forté Framework classes
using Array, HashTable etc.
Raymond Blum wrote:
>
Eric
Although I have not looked at them in a while, I remember the Born
Collection Classes having some HashTable and Iterator functionality that
might be worth looking at as an alternative.
The last version I had is 1.2 and was offered under the GNU license,
there may be something newer, check out
http://www.born.com
or email
[email protected]
On Thu, 6 May 1999, Fingerhut, Eric wrote:
We have been using the hashtable class in our application, and have recently
hit performance problems that lead us to the following questions:
1) Forte's hashing algorithm - we are concerned that Forte's hashing
algorithm may not be ideal or even adequate for our data; does anyone know
how it works?
2) Hash table performance - any ideas on how to guage it?
3) Is anyone aware of a binary tree implementation that might be
available?
Dr. Thomas Kunst mailto:[email protected]
sd&m GmbH & Co. KG http://www.sdm.de
software design & management
Thomas-Dehler-Str. 27, 81737 Muenchen, Germany
Tel +49 89 63812-221 Fax -444
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>I'm trying to understand what you have and what you are trying to do. First of all, the Web PL/SQL generator requires you to generate Table APIs (TAPIs) for every table referenced in a module component. If you created one based on a view, the only way to get it to work is to generate a TAPI on the view, which Designer doesn't do natively. I've fooled Designer into generating a view TAPI by creating a table definition that looks exactly like the view and has the same name, and generating the TAPI for that table. Even then, I have to hand-modify the resulting TAPI to remove references to ROWID, since views don't have rowids.
I've never tried generating TAPI against a materialized view (MV) - it might work, since there really is a table to instantiate the MV, but it might require the same work around as the view.
As for the reference in the module component definition, I think you have to delete the old table reference and create a new one. I'm not sure what you are doing with "copy object". Remapping is usually done when you are copying an object from one application system to another, and want the references to point at equivalent objects in the new application system, not the objects in the old one. -
We have been using the hashtable class in our application, and have recently
hit performance problems that lead us to the following questions:
1) Forte's hashing algorithm - we are concerned that Forte's hashing
algorithm may not be ideal or even adequate for our data; does anyone know
how it works?
2) Hash table performance - any ideas on how to guage it?
3) Is anyone aware of a binary tree implementation that might be
available?
Much thanks in advance,
Eric
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>We have been using the hashtable class in our application, and have recently
hit performance problems that lead us to the following questions:
1) Forte's hashing algorithm - we are concerned that Forte's hashing
algorithm may not be ideal or even adequate for our data; does anyone know
how it works?
2) Hash table performance - any ideas on how to guage it?
3) Is anyone aware of a binary tree implementation that might be
available?
Much thanks in advance,
Eric
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/> -
i have program that reveived the input through JTextField ,
then i want it to search for that value in hash table and display it in an JTextArea,
i only don't know how to search the value of input in the hash table and display it in JTextArea?xtremliep wrote:
Hi dapim,
have a look at the example here:
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Hashtable.html
If your Hashtable looks like this:
Hashtable numbers = new Hashtable();
numbers.put("one", new Integer(1));
numbers.put("two", new Integer(2));
numbers.put("three", new Integer(3));You could access it like this
Integer n = (Integer)numbers.get(JTextField.getText());
- use the interface not the implementation as declaring type
- use HashMap not Hashtable if it's only accessed by a single thread
- use generics
- use autoboxing to allow the reuse of objects
So this code would look like this:
Map<String, Integer> numbers = new HashMap<String, Integer>();
numbers.put("one", 1);
numbers.put("two", 2);
numbers.put("three", 3);
int n = numbers.get(myTextField.getText());-Puce -
Is it possible to implement a List with a hash table?
The Java "collections" all use different methods of holding the data. Each is suited to different circumstances.
Vector and ArrayList keep the data in a plain vanilla array, but with the magic that they keep track of how much of the array is actually being used, and if you try to add another entry when the array is full, they make a new, bigger array, copy all the data from the old array to the new array, and then make the old array available for garbage collection. (The main difference between Vector and ArrayList is that Vector is synchronized, i.e. it will not become corrupted if multiple threads attempt to access it at the same time. ArrayList is not synchronized, which means that in the normal case where only one thread is accessing it, it is faster.)
In a LinkedList each entry has handles to the next entry in the list and the previous entry.
In a Hashtable the entries are stored in an array, but the index of the array entry is calculated using a formula based on the hash key. The hash formula is basically, divide the hashkey by the number of entries in the array and take the remainder. The hashkey itself depends on the object, but basically it is a formula that generates an integer out of something that can be considered teh "key value" of the object. It is possible -- indeed it happens all the time -- that two different objects will have the same hash key or that two objects with different hash keys will hash to the same index, so hashtable does some extra work to deal with such "collisions".
Each has its advantages. You can find an entry very quickly in a Hashtable: you find the hashkey, perform the hash function, go to that entry in the array, and kablam, you're there. The time to find an entry in the hashtable is independent of the number of entries in the table. Compare this to a Vector or LinkedList, where the only one to find a desired entry is to start at the beginning and search one by one until you find the one you want. The main drawback to a Hashtable is that the order you get out of the hash function is essentially random. You can read a Hashtable sequentially but the order has no particular significance.
A LinkedList is a good choice when order is important and there are a lot of inserts and/or deletes in the middle of the list. All that is necessary to add an entry is to change the handles on the entries that come before and after. While in your mind you might picture all the entries after being moved down to make room, physically none of them have to move, all that changes is handles. The main drawbacks to a LinkedList are: (a) there's some overhead involved in storing the handles and keeping them updated; and (b) it's not easy to jump to an arbitrary entry number, like if you want #12, you would have to loop through the first 11.
Vector and ArrayList are fast and simple when you are only or mostly adding or removing from the end of the list, and when you don't often need to search by key. -
Displaying graphical representation of data in hash tables as bar chart?
I want to be able to display results in my hash table as a bar chart i don't know how to do it could someone help me I've looked through tutorials couldn't find any information that actually helped.
In my program it doesnt allow matching the capital and small letters
so for instance if I already have Mike it allows for me to input mike in again so there are 2 Mikes.
I also want to do a simple user interface the tutorial for it is not simple to understand could any one tell me how to create a simple user interface like putting a button into a place wher i want it to be.
im not asking anyone to do it for me i just want people to show me how to do it
thank you
Edited by: Tek_Hedef on Dec 1, 2007 4:30 AMThanks for the ideas pal but I did have a go at it but my bit of code is making it crash but i removed it now so here's what I have so far
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
class StudentDetails extends JFrame implements ActionListener
private JTextField StudentNameTxt, StudentMarkTxt;
private JButton DeleteStudentDetailsBtn, DisplayAllStudentsBtn, SearchStudentBtn, FailedStudentsBtn, PassedStudentsBtn, DistinctionStudentsBtn, AddStudentDetailsBtn, ExitBtn;
private JPanel DisplayStudentDetailsPnl;
private JLabel StudentNameLbl, StudentMarkLbl;
private JTextArea DisplayResultsTxt;
private Hashtable StudentDetailsTbl;
private String StudentName, StudentMark;
public static void main(String[] args)
StudentDetails frame = new StudentDetails();
frame.setSize(600,600);
frame.createGUI();
frame.setVisible(true);
public void display(JPanel DisplayStudentDetailsPnl)
Graphics paper = DisplayStudentDetailsPnl.getGraphics();
paper.setColor(Color.white);
paper.fillRect(0, 0, 500, 500);
paper.setColor(new Color((int)(Math.random()*255),(int)(Math.random()*255),(int)(Math.random()*255) ));
private void createGUI()
setDefaultCloseOperation(EXIT_ON_CLOSE);
Container window = getContentPane();
window.setLayout(new FlowLayout());
StudentDetailsTbl = new Hashtable();
StudentNameLbl = new JLabel("Student Name");
window.add(StudentNameLbl);
StudentNameTxt = new JTextField(15);
window.add(StudentNameTxt);
StudentMarkLbl = new JLabel("Student Mark");
window.add(StudentMarkLbl);
StudentMarkTxt = new JTextField(3);
window.add(StudentMarkTxt);
AddStudentDetailsBtn = new JButton("Add Student and Mark");
window.add(AddStudentDetailsBtn);
AddStudentDetailsBtn.addActionListener(this);
DeleteStudentDetailsBtn = new JButton("Delete Student");
window.add(DeleteStudentDetailsBtn);
DeleteStudentDetailsBtn.addActionListener(this);
DisplayAllStudentsBtn = new JButton("Display all Students and Marks");
window.add(DisplayAllStudentsBtn);
DisplayAllStudentsBtn.addActionListener(this);
SearchStudentBtn = new JButton("Search Student");
window.add(SearchStudentBtn);
SearchStudentBtn.addActionListener(this);
FailedStudentsBtn = new JButton("Students which Failed");
window.add(FailedStudentsBtn);
FailedStudentsBtn.addActionListener(this);
PassedStudentsBtn = new JButton("Students which Passed");
window.add(PassedStudentsBtn);
PassedStudentsBtn.addActionListener(this);
DistinctionStudentsBtn = new JButton("Students with Distinction");
window.add(DistinctionStudentsBtn);
DistinctionStudentsBtn.addActionListener(this);
ExitBtn = new JButton("Exit");
window.add(ExitBtn);
ExitBtn.addActionListener(this);
DisplayResultsTxt = new JTextArea();
DisplayResultsTxt.setPreferredSize(new Dimension(200, 200));
DisplayResultsTxt.setBackground(Color.white);
window.add(DisplayResultsTxt);
DisplayResultsTxt.enable(false);
public void actionPerformed (ActionEvent e)
if (e.getSource()== AddStudentDetailsBtn)
StudentName = StudentNameTxt.getText();
StudentMark = StudentMarkTxt.getText();
DisplayResultsTxt.setText("");
StudentDetailsTbl.put(StudentName, StudentMark);
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
String[] keys = (String[]) StudentDetailsTbl.keySet().toArray(new String[0]);
Arrays.sort(keys);
for (String key : keys)
DisplayResultsTxt.append(key + " : " + StudentDetailsTbl.get(key)+ "\n");
StudentNameTxt.setText("");
StudentMarkTxt.setText("");
if (e.getSource() == DeleteStudentDetailsBtn )
if (StudentDetailsTbl.containsKey(StudentNameTxt.getText().trim()))
DisplayResultsTxt.setText("");
String txt = StudentNameTxt.getText();
Enumeration enumStudentName = StudentDetailsTbl.keys() ;
String currentelement = (String)enumStudentName.nextElement();
StudentDetailsTbl.remove(txt);
DisplayResultsTxt.append(txt + " has been deleted");
if (e.getSource() == SearchStudentBtn)
if (StudentDetailsTbl.containsKey(StudentNameTxt.getText().trim()))
String txt = StudentNameTxt.getText();
String result;
DisplayResultsTxt.setText("");
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
while (enumStudentName.hasMoreElements())
String currentelement = (String)enumStudentName.nextElement();
result = (StudentDetailsTbl.get(currentelement).toString());
if (txt.equals(currentelement))
DisplayResultsTxt.append(currentelement + " " + result);
else JOptionPane.showMessageDialog(null, "Student Name could not be identified");
if (e.getSource() == DisplayAllStudentsBtn)
DisplayResultsTxt.setText("");
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
while (enumStudentName.hasMoreElements())
DisplayResultsTxt.append(enumStudentName.nextElement()+ " " + enumStudentMark.nextElement()+ "\n");
if (e.getSource() == PassedStudentsBtn)
DisplayResultsTxt.setText("");
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
while (enumStudentName.hasMoreElements())
int Mark = Integer.parseInt((String)enumStudentMark.nextElement());
String Name = (String)enumStudentName.nextElement();
if (Mark >=40)
DisplayResultsTxt.append(Name + " " + Mark + "\n");
if (e.getSource() == FailedStudentsBtn)
DisplayResultsTxt.setText("");
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
while (enumStudentName.hasMoreElements())
int Mark = Integer.parseInt((String)enumStudentMark.nextElement());
String Name = (String)enumStudentName.nextElement();
if (Mark <40)
DisplayResultsTxt.append(Name + " " + Mark + "\n");
if (e.getSource() == DistinctionStudentsBtn)
DisplayResultsTxt.setText("");
Enumeration enumStudentName = StudentDetailsTbl.keys();
Enumeration enumStudentMark = StudentDetailsTbl.elements();
while (enumStudentName.hasMoreElements())
int Mark = Integer.parseInt((String)enumStudentMark.nextElement());
String Name = (String)enumStudentName.nextElement();
if (Mark >=75)
DisplayResultsTxt.append(Name + " " + Mark + "\n");
} -
How about use partial key to loop at a hashed table?
Such as I want to loop a Internal table of BSID according to BKPF.
data itab_bsid type hashed table of BSID with unique key bukrs belnr gjahr buzid.
Loop at itab_bsid where bukrs = wa_bkpf-bukrs
and belnr = wa_bkpf-belnr
and gjahr = wa_bkpf-gjahr.
endloop.
I know if you use all key to access this hashed table ,it is certainly quick, and my question is when i use partial key of this internal hashed table to loop it, how about its performance.
Another question is in this case(BSID have many many record) , Sorted table and Hashed table , Which is better in performance.You can't cast b/w data reference which l_tax is and object reference which l_o_tax_code is.
osref is a generic object type and you store a reference to some object in it, right? So the question is: what kind of object you store there? Please note - this must be an object reference , not data reference .
i.e
"here goes some class
class zcl_spfli definition.
endclass.
class zcl_spfli implementation.
endclass.
"here is an OBJECT REFERENCE for it, (so I refer to a class) i.e persistent object to table SPFLI
data oref_spfli type ref to zcl_spfli.
"but here I have a DATA REFERENCE (so I refer to some data object) i.e DDIC structure SPFLI
data dref_spfli type ref to spfli.
So my OSREF can hold only oref_spfli but it not intended for dref_spfli . That's why you get this syntax error. Once you have stored reference to zcl_spfli in osref then you will be able to dereference it and access this object's attributes.
data: osref type osref.
create object osref_spfli.
osref = osref_spfli.
"now osref holds reference to object, you can deference it
oref_spfli ?= osref.
osref_spfli->some_attribute = ....
OSREFTAB is just a table whose line is of type OSREF (so can hold multiple object references - one in each line).
Regards
Marcin -
How to use one hash table inside another hash table
Hi everyone,
Any example of hash table inside another hash table.
Can one here help me how to write one hash table inside another with repeating keys for the first hash table.
Thanks,
kanty.Do you mean you want the 'value' entries in a hash table to themselves be hash tables? Easy but this often indicates a design flaw.
Hashtable<String,<Hashtable<String,Value>> fred = new Hashtable<String,<Hashtable<String,Value>> ();But what do you mean by "with repeating keys for the first hash table"?
Edited by: sabre150 on Jul 2, 2010 10:11 PM
Looks like you have already handled the declaration side in your other thread. I suspect you should be writing your own beans that hold the information and these beans would then be stored in a Map. The problem I have is that your description is too vague so I can't be certain. -
I am trying to build a proof of concept where a WPF form is hosted in a seperate runspace and updates are handled from the primary shell/runspace. I have had some success thanks to a great article by Boe Prox, but I am having an issue I wanted to open up
to see if anyone had a suggestion.
My goals are as follows:
1.) Set control properties from the primary runspace (Completed)
2.) Get control properties from the primary runspace (Completed)
3.) Respond to WPF form events in the UI runspace from the primary runspace (Kind of broken).
I have the ability to read/write values to the form, but I am having difficulty with events. Specifically, I can fire and handle events, but the minute I try to reference the $SyncHash from within the event it appears to cause a blocking condition hanging both
runspaces. As a result, I am unable to update the form based on an event being fired by a control.
In the example below, the form is loaded and the following steps occur:
1.) Update-Combobox is called and it populates the combobox with a list of service names and selects the first item.
2.) update-textbox is called and sets the Text property of the textbox.
3.) The Text value of the textbox is read by the function read-textbox and output using write-host.
4.) An event handle is registered for the SelectionChanged event for the combobox to call the update-textbox function used earlier.
5.) If you change the selection on the combobox, the shell and UI hangs as soon as $SyncHash is referenced. I suspect this is causing some sort of blocking condition from multiple threads trying to access the synchronized nature of the hash table, but I am
unsure as to why / how to work around it. If you comment out the line "$SyncHash.TXT_Output.Dispatcher.Invoke("Send",[action]{$SyncHash.TXT_Output.Text = $Value})" within update-textbox the event handler will execute/complete.
$UI_JobScript =
try{
Function New-Form ([XML]$XAML_Form){
$XML_Node_Reader=(New-Object System.Xml.XmlNodeReader $XAML_Form)
[Windows.Markup.XamlReader]::Load($XML_Node_Reader)
try{
Add-Type –AssemblyName PresentationFramework
Add-Type –AssemblyName PresentationCore
Add-Type –AssemblyName WindowsBase
catch{
Throw "Unable to load the requisite Windows Presentation Foundation assemblies. Please verify that the .NET Framework 3.5 Service Pack 1 or later is installed on this system."
$Form = New-Form -XAML_Form $SyncHash.XAML_Form
$SyncHash.Form = $Form
$SyncHash.CMB_Services = $SyncHash.Form.FindName("CMB_Services")
$SyncHash.TXT_Output = $SyncHash.Form.FindName("TXT_Output")
$SyncHash.Form.ShowDialog() | Out-Null
$SyncHash.Error = $Error
catch{
write-host $_.Exception.Message
#End UI_JobScript
#Begin Main
add-type -AssemblyName WindowsBase
[XML]$XAML_Form = @"
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Window.Resources>
<DataTemplate x:Key="DTMPL_Name">
<TextBlock Text="{Binding Path=Name}" />
</DataTemplate>
</Window.Resources>
<DockPanel LastChildFill="True">
<StackPanel Orientation="Horizontal" DockPanel.Dock="Top">
<Label Name="LBL_Services" Content="Services:" />
<ComboBox Name="CMB_Services" ItemTemplate="{StaticResource DTMPL_Name}"/>
</StackPanel>
<TextBox Name="TXT_Output"/>
</DockPanel>
</Window>
$SyncHash = [hashtable]::Synchronized(@{})
$SyncHash.Add("XAML_Form",$XAML_Form)
$SyncHash.Add("InitialScript", $InitialScript)
$Normal = [System.Windows.Threading.DispatcherPriority]::Normal
$UI_Runspace =[RunspaceFactory]::CreateRunspace()
$UI_Runspace.ApartmentState = [System.Threading.ApartmentState]::STA
$UI_Runspace.ThreadOptions = [System.Management.Automation.Runspaces.PSThreadOptions]::ReuseThread
$UI_Runspace.Open()
$UI_Runspace.SessionStateProxy.SetVariable("SyncHash",$SyncHash)
$UI_Pipeline = [PowerShell]::Create()
$UI_Pipeline.Runspace=$UI_Runspace
$UI_Pipeline.AddScript($UI_JobScript) | out-Null
$Job = $UI_Pipeline.BeginInvoke()
$SyncHash.ServiceList = get-service | select name, status | Sort-Object -Property Name
Function Update-Combobox{
write-host "`nBegin Update-Combobox [$(get-date)]"
$SyncHash.CMB_Services.Dispatcher.Invoke($Normal,[action]{$SyncHash.CMB_Services.ItemsSource = $SyncHash.ServiceList})
$SyncHash.CMB_Services.Dispatcher.Invoke($Normal,[action]{$SyncHash.CMB_Services.SelectedIndex = 0})
write-host "`End Update-Combobox [$(get-date)]"
Function Update-Textbox([string]$Value){
write-host "`nBegin Update-Textbox [$(get-date)]"
$SyncHash.TXT_Output.Dispatcher.Invoke("Send",[action]{$SyncHash.TXT_Output.Text = $Value})
write-host "End Update-Textbox [$(get-date)]"
Function Read-Textbox(){
write-host "`nBegin Read-Textbox [$(get-date)]"
$SyncHash.TXT_Output.Dispatcher.Invoke($Normal,[action]{$Global:Return = $SyncHash.TXT_Output.Text})
$Global:Return
remove-variable -Name Return -scope Global
write-host "End Read-Textbox [$(get-date)]"
#Give the form some time to load in the other runspace
$MaxWaitCycles = 5
while (($SyncHash.Form.IsInitialized -eq $Null)-and ($MaxWaitCycles -gt 0)){
Start-Sleep -Milliseconds 200
$MaxWaitCycles--
Update-ComboBox
Update-Textbox -Value $("Initial Load: $(get-date)")
Write-Host "Value Read From Textbox: $(Read-TextBox)"
Register-ObjectEvent -InputObject $SyncHash.CMB_Services -EventName SelectionChanged -SourceIdentifier "CMB_Services.SelectionChanged" -action {Update-Textbox -Value $("From Selection Changed Event: $(get-date)")}Thanks again for the responses. This may not be possible, but I thought I would throw it out there. I appreciate your help in looking into this.
To clarify the "Respond to control events in the main runspace"... I'm would like to have an event generated by a form object in the UI runspace (ex: combo box selectionchanged event) trigger a delegate within the main runspace and have that delegate in
the main runspace update the form in the UI runspace.
ex:
1.) User changes selection on combo box generating form event
2.) Event calls delegate (which I have gotten to work)
3.) Delegate does some basic processing (works)
4.) Delegate attempts to update form in UI runspace (hangs)
As to the delegates / which runspace they are running in. I see the $synchash variable if I run get-var within a delegate, but I do not see the $Form variable so I am assuming that they are in the main runspace. Do you agree with that assumption? -
How Hash tables can be used in PI mapping
Hi Experts,
I'm don't have any idea how we store the values in hash tables and how to implement them in mapping.
In my scenario I have two fields matnum and quantity.if matnum is not null ,then we have to check whether the matnum exists in hash table and also check whether the hash table is empty or not.
How we can do this in graphical message mapping?
how to store the variable matnum in a table?
If global variables are used, how to implement in mapping.how we call the keys from hash table ?Divya,
We have a similiar requirement for getting different values. Below param1 may you be matnum,param2 is quantity
What you need to do is first declare global varaible(A), fill hash table as below(B) and retrieve(C) based on index. You can tweak code based on your requirement
(A) Declare global variable(last icon in message mapping tool bar)
String globlalString[] = new String[10];
(B) Fill Hash Table
import java.util.Hashtable;
public void saveparam1(String[] param1,String[] param2,ResultList result,Container container){
Hashtable htparam1 = new Hashtable();
int Indx = 0;
for (int i = 0 ;i < param1.length ; i++) {
String strparam1 = param1<i>.trim();
if (strparam1.length() > 0) {
Object obj = htparam1.get(strparam1);
if (obj == null){
globlalString[Indx++] = strparam1 ;
htparam1.put(strparam1,strparam1);
if (Indx < globalString.length) {
for (int i = 0; i < param2.length ; i++) {
String strparam2 = param2<i>.trim();
if (strparam2.length() > 0) {
Object obj = htparam1.get(strparam2);
if (obj == null){
globalString[Indx++] = strparam2 ;
htparam1.put(strparam2,strparam2);
result.addValue(globalString[0]); // for first value
(C) for subsequent reading/accessing
//pass constant whatever number is required to this function
String retValue = "";
int indx = Integer.parseInt(index);
indx = indx - 1;
if ((indx >= 0) && (indx < globalString.length)){
retValue = globalString[indx];
return retValue;
Hope this helps! -
How to create hashed table in runtime
hi experts
how to create hashed table in runtime, please give me the coading style.
please help me.
regards
subhasisHi,
Have alook at the code, and pls reward points.
Use Hashed Tables to Improve Performance :
report zuseofhashedtables.
Program: ZUseOfHashedTables **
Author: XXXXXXXXXXXXXXXXXX **
Versions: 4.6b - 4.6c **
Notes: **
this program shows how we can use hashed tables to improve **
the responce time. **
It shows, **
1. how to declare hashed tables **
2. a cache-like technique to improve access to master data **
3. how to collect data using hashed tables **
4. how to avoid deletions of unwanted data **
Results: the test we run read about 31000 rows from mkpf, 150000 **
rows from mseg, 500 rows from makt and 400 from lfa1. **
it filled ht_lst with 24500 rows and displayed them in **
alv grid format. **
It needed about 65 seconds to perform this task (with **
all the db buffers empty) **
The same program with standard tables needed 140 seconds **
to run with the same recordset and with buffers filled in **
Objetive: show a list that consists of all the material movements **
'101' - '901' for a certain range of dates in mkpf-budat. **
the columns to be displayed are: **
mkpf-budat, **
mkpf-mblnr, **
mseg-lifnr, **
lfa1-name1, **
mkpf-xblnr, **
mseg-zeile **
mseg-charg, **
mseg-matnr, **
makt-maktx, **
mseg-erfmg, **
mseg-erfme. **
or show a sumary list by matnr - menge **
You'll have to create a pf-status called vista - **
See form set_pf_status for details **
tables used -
tables: mkpf,
mseg,
lfa1,
makt.
global hashed tables used
data: begin of wa_mkpf, "header
mblnr like mkpf-mblnr,
mjahr like mkpf-mjahr,
budat like mkpf-budat,
xblnr like mkpf-xblnr,
end of wa_mkpf.
data: ht_mkpf like hashed table of wa_mkpf
with unique key mblnr mjahr
with header line.
data: begin of wa_mseg, " line items
mblnr like mseg-mblnr,
mjahr like mseg-mjahr,
zeile like mseg-zeile,
bwart like mseg-bwart,
charg like mseg-charg,
matnr like mseg-matnr,
lifnr like mseg-lifnr,
erfmg like mseg-erfmg,
erfme like mseg-erfme,
end of wa_mseg.
data ht_mseg like hashed table of wa_mseg
with unique key mblnr mjahr zeile
with header line.
cache structure for lfa1 records
data: begin of wa_lfa1,
lifnr like lfa1-lifnr,
name1 like lfa1-name1,
end of wa_lfa1.
data ht_lfa1 like hashed table of wa_lfa1
with unique key lifnr
with header line.
cache structure for material related data
data: begin of wa_material,
matnr like makt-matnr,
maktx like makt-maktx,
end of wa_material.
data: ht_material like hashed table of wa_material
with unique key matnr
with header line.
result table
data: begin of wa_lst, "
budat like mkpf-budat,
mblnr like mseg-mblnr,
lifnr like mseg-lifnr,
name1 like lfa1-name1,
xblnr like mkpf-xblnr,
zeile like mseg-zeile,
charg like mseg-charg,
matnr like mseg-matnr,
maktx like makt-maktx,
erfmg like mseg-erfmg,
erfme like mseg-erfme,
mjahr like mseg-mjahr,
end of wa_lst.
data: ht_lst like hashed table of wa_lst
with unique key mblnr mjahr zeile
with header line.
data: begin of wa_lst1, " sumary by material
matnr like mseg-matnr,
maktx like makt-maktx,
erfmg like mseg-erfmg,
erfme like mseg-erfme,
end of wa_lst1.
data: ht_lst1 like hashed table of wa_lst1
with unique key matnr
with header line.
structures for alv grid display.
itabs
type-pools: slis.
data: it_lst like standard table of wa_lst with header line,
it_fieldcat_lst type slis_t_fieldcat_alv with header line,
it_sort_lst type slis_t_sortinfo_alv,
it_lst1 like standard table of wa_lst1 with header line,
it_fieldcat_lst1 type slis_t_fieldcat_alv with header line,
it_sort_lst1 type slis_t_sortinfo_alv.
structures
data: wa_sort type slis_sortinfo_alv,
ls_layout type slis_layout_alv.
global varialbes
data: g_lines type i.
data: g_repid like sy-repid,
ok_code like sy-ucomm.
selection-screen
"text: Dates:
select-options: so_budat for mkpf-budat default sy-datum.
"text: Material numbers.
select-options: so_matnr for mseg-matnr.
selection-screen uline.
selection-screen skip 1.
"Text: show summary by material.
parameters: gp_bymat as checkbox default ''.
start-of-selection.
perform get_data.
perform show_data.
end-of-selection.
FORM get_data *
form get_data.
select mblnr mjahr budat xblnr
into table ht_mkpf
from mkpf
where budat in so_budat. " make use of std index.
have we retrieved data from mkpf?
describe table ht_mkpf lines g_lines.
if g_lines > 0.
if true then retrieve all related records from mseg.
Doing this way we make sure that the access is by primary key
of mseg.
The reason is that is faster to filter them in memory
than to allow the db server to do it.
select mblnr mjahr zeile bwart charg
matnr lifnr erfmg erfme
into table ht_mseg
from mseg
for all entries in ht_mkpf
where mblnr = ht_mkpf-mblnr
and mjahr = ht_mkpf-mjahr.
endif.
fill t_lst or t_lst1 according to user's choice.
if gp_bymat = ' '.
perform fill_ht_lst.
else.
perform fill_ht_lst1.
endif.
endform.
form fill_ht_lst.
refresh ht_lst.
Example: how to discard unwanted data in an efficient way.
loop at ht_mseg.
filter unwanted data
check ht_mseg-bwart = '101' or ht_mseg-bwart = '901'.
check ht_mseg-matnr in so_matnr.
read header line.
read table ht_mkpf with table key mblnr = ht_mseg-mblnr
mjahr = ht_mseg-mjahr.
clear ht_lst.
* note : this may be faster if you specify field by field.
move-corresponding ht_mkpf to ht_lst.
move-corresponding ht_mseg to ht_lst.
perform read_lfa1 using ht_mseg-lifnr changing ht_lst-name1.
perform read_material using ht_mseg-matnr changing ht_lst-maktx.
insert table ht_lst.
endloop.
endform.
form fill_ht_lst1.
refresh ht_lst1.
Example: how to discard unwanted data in an efficient way.
hot to simulate a collect in a faster way
loop at ht_mseg.
filter unwanted data
check ht_mseg-bwart = '101' or ht_mseg-bwart = '901'.
check ht_mseg-matnr in so_matnr.
* note : this may be faster if you specify field by field.
read table ht_lst1 with table key matnr = ht_mseg-matnr
transporting erfmg.
if sy-subrc <> 0. " if matnr doesn't exist in sumary table
" insert a new record
ht_lst1-matnr = ht_mseg-matnr.
perform read_material using ht_mseg-matnr changing ht_lst1-maktx.
ht_lst1-erfmg = ht_mseg-erfmg.
ht_lst1-erfme = ht_mseg-erfme.
insert table ht_lst1.
else." a record was found.
" collect erfmg. To do so, fill in the unique key and add
" the numeric fields.
ht_lst1-matnr = ht_mseg-matnr.
add ht_mseg-erfmg to ht_lst1-erfmg.
modify table ht_lst1 transporting erfmg.
endif.
endloop.
endform.
implementation of cache for lfa1.
form read_lfa1 using p_lifnr changing p_name1.
read table ht_lfa1 with table key lifnr = p_lifnr
transporting name1.
if sy-subrc <> 0.
clear ht_lfa1.
ht_lfa1-lifnr = p_lifnr.
select single name1
into ht_lfa1-name1
from lfa1
where lifnr = p_lifnr.
if sy-subrc <> 0. ht_lfa1-name1 = 'n/a in lfa1'. endif.
insert table ht_lfa1.
endif.
p_name1 = ht_lfa1-name1.
endform.
implementation of cache for material data
form read_material using p_matnr changing p_maktx.
read table ht_material with table key matnr = p_matnr
transporting maktx.
if sy-subrc <> 0.
ht_material-matnr = p_matnr.
select single maktx into ht_material-maktx
from makt
where spras = sy-langu
and matnr = p_matnr.
if sy-subrc <> 0. ht_material-maktx = 'n/a in makt'. endif.
insert table ht_material.
endif.
p_maktx = ht_material-maktx.
endform.
form show_data.
if gp_bymat = ' '.
perform show_ht_lst.
else.
perform show_ht_lst1.
endif.
endform.
form show_ht_lst.
"needed because the FM can't use a hashed table.
it_lst[] = ht_lst[].
perform fill_layout using 'full display'
changing ls_layout.
perform fill_columns_lst.
perform sort_lst.
g_repid = sy-repid.
call function 'REUSE_ALV_GRID_DISPLAY'
exporting
i_callback_program = g_repid
i_callback_pf_status_set = 'SET_PF_STATUS'
is_layout = ls_layout
it_fieldcat = it_fieldcat_lst[]
it_sort = it_sort_lst
tables
t_outtab = it_lst
exceptions
program_error = 1
others = 2.
endform.
form show_ht_lst1.
"needed because the FM can't use a hashed table.
it_lst1[] = ht_lst1[].
perform fill_layout using 'Sumary by matnr'
changing ls_layout.
perform fill_columns_lst1.
perform sort_lst.
g_repid = sy-repid.
call function 'REUSE_ALV_GRID_DISPLAY'
exporting
i_callback_program = g_repid
i_callback_pf_status_set = 'SET_PF_STATUS'
is_layout = ls_layout
it_fieldcat = it_fieldcat_lst1[]
it_sort = it_sort_lst
tables
t_outtab = it_lst1
exceptions
program_error = 1
others = 2.
endform.
form fill_layout using p_window_titlebar
changing cs_layo type slis_layout_alv.
clear cs_layo.
cs_layo-window_titlebar = p_window_titlebar.
cs_layo-edit = 'X'.
cs_layo-edit_mode = space.
endform. " armar_layout_stock
form set_pf_status using rt_extab type slis_t_extab.
create a new status
and then select extras -> adjust template -> listviewer
set pf-status 'VISTA'.
endform. "set_pf_status
define add_lst.
clear it_fieldcat_lst.
it_fieldcat_lst-fieldname = &1.
it_fieldcat_lst-outputlen = &2.
it_fieldcat_lst-ddictxt = 'L'.
it_fieldcat_lst-seltext_l = &1.
it_fieldcat_lst-seltext_m = &1.
it_fieldcat_lst-seltext_m = &1.
if &1 = 'MATNR'.
it_fieldcat_lst-emphasize = 'C111'.
endif.
append it_fieldcat_lst.
end-of-definition.
define add_lst1.
clear it_fieldcat_lst.
it_fieldcat_lst1-fieldname = &1.
it_fieldcat_lst1-outputlen = &2.
it_fieldcat_lst1-ddictxt = 'L'.
it_fieldcat_lst1-seltext_l = &1.
it_fieldcat_lst1-seltext_m = &1.
it_fieldcat_lst1-seltext_m = &1.
append it_fieldcat_lst1.
end-of-definition.
form fill_columns_lst.
set columns for output.
refresh it_fieldcat_lst.
add_lst 'BUDAT' 10.
add_lst 'MBLNR' 10.
add_lst 'LIFNR' 10.
add_lst 'NAME1' 35.
add_lst 'XBLNR' 15.
add_lst 'ZEILE' 5.
add_lst 'CHARG' 10.
add_lst 'MATNR' 18.
add_lst 'MAKTX' 30.
add_lst 'ERFMG' 17.
add_lst 'ERFME' 5.
add_lst 'MJAHR' 4.
endform.
form fill_columns_lst1.
set columns for output.
refresh it_fieldcat_lst1.
add_lst1 'MATNR' 18.
add_lst1 'MAKTX' 30.
add_lst1 'ERFMG' 17.
add_lst1 'ERFME' 5..
endform.
Regards,
Ameet -
How to implement "SelectAll" function in table view?
hi, experts
i want to implement "SelectAll" function in table view, just like the SelectAll function in ALV,how to do?
and, can table view has it's tool bar ,may be on top of it.
pls help and thanks a lot!!Search this forum. You will find plenty of threads on the same...
Raja
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