I tried to use reverseBystack, reverseBylink and remove.. but I don't know why when i use these functions, it has error like this.
Exception in thread "main" java.lang.NullPointerException
at LinkedQueue$Node.access$200(LinkedQueue.java:44)
at LinkedQueue.reverseBylink(LinkedQueue.java:185)
at LinkedQueue.main(LinkedQueue.java:238)
void reverseByStack() - This method reverses the order of the items in the linked list (first
becomes last and last becomes first) using a stack data strucenter code hereture`
• void reverseByLinks() - This method also reverses the order of the items in the linked list.
It should not create a new list or use a stack. It should only reverse the order of the nodes by
modifying the next values for each node in the list.
• int remove(Item item) - This method scans the queue for occurrences of item and removes
them from the queue. It returns the number of items deleted from the queue.
these are what i want to make.
enter code here public class LinkedQueue<Item> implements Iterable<Item> {
private int N; // number of elements on queue
private Node first; // beginning of queue
private Node last; // end of queue
// helper linked list class
private class Node {
private Item item;
private Node next;
}
public LinkedQueue() {
first = null;
last = null;
N = 0;
assert check();
}
public boolean isEmpty() {
return first == null;
}
public int size() {
return N;
}
public Item peek() {
if (isEmpty()) throw new NoSuchElementException("Queue
underflow");
return first.item;
}
public void enqueue(Item item) {
Node oldlast = last;
last = new Node();
last.item = item;
last.next = null;
if (isEmpty()) first = last;
else oldlast.next = last;
N++;
assert check();
}
public Item dequeue() {
if (isEmpty()) throw new NoSuchElementException("Queue
underflow");
Item item = first.item;
first = first.next;
N--;
if (isEmpty()) last = null; // to avoid loitering
assert check();
return item;
}
public String toString() {
StringBuilder s = new StringBuilder();
for (Item item : this)
s.append(item + " ");
return s.toString();
}
private boolean check() {
if (N == 0) {
if (first != null) return false;
if (last != null) return false;
}
else if (N == 1) {
if (first == null || last == null) return false;
if (first != last) return false;
if (first.next != null) return false;
}
else {
if (first == last) return false;
if (first.next == null) return false;
if (last.next != null) return false;
// check internal consistency of instance variable N
int numberOfNodes = 0;
for (Node x = first; x != null; x = x.next) {
numberOfNodes++;
}
if (numberOfNodes != N) return false;
// check internal consistency of instance variable last
Node lastNode = first;
while (lastNode.next != null) {
lastNode = lastNode.next;
}
if (last != lastNode) return false;
}
return true;
}
void reverseBystack(){
Stack<Item> s = new Stack<>();
Item item;
while (s.isEmpty() != true){
item = dequeue();
s.push(item);
}
while(s.isEmpty() != true){
item = s.pop();
enqueue(item);
}
}
void reverseBylink() {
Node prev = null;
Node current = this.first;
Node next = null;
while (current != null) {
next = current.next;
current.next = prev;
prev = current;
current = next;
}
prev.next = current.next;
}
int remove(Item item){
Node cur = first;
Node prev = last;
while(cur != null) {
if(cur.item.equals(item))
System.out.println(cur.item);
}
cur = cur.next;
prev = cur.next;
return 0;
}
public Iterator<Item> iterator() {
return new ListIterator();
}
private class ListIterator implements Iterator<Item> {
private Node current = first;
public boolean hasNext() { return current != null;
}
public void remove() { throw new
UnsupportedOperationException(); }
public Item next() {
if (!hasNext()) throw new NoSuchElementException();
Item item = current.item;
current = current.next;
return item;
}
}
/**
* Unit tests the <tt>LinkedQueue</tt> data type.
*/
public static void main(String[] args) {
LinkedQueue<String> q = new LinkedQueue<String>();
while (!StdIn.isEmpty()) {
String item = StdIn.readString();
if (!item.equals("-")) q.reverseBylink();
else if (!q.isEmpty()) StdOut.print(q.dequeue() + " ");
}
StdOut.println("(" + q.size() + " left on queue)");
}
}
I am evaluating the performance of Microsoft's implementation of Avro, and at first I thought I was getting phenomenal performance until I realized it just wasn't serializing the entire message ;-)
In the following there is a simple hierarchy of messages decorated with [DataContract] (a base and two derived types). All members are decorated with the [DataMember] attribute. I create a serializer from the base message type and serialize a list of derived messages, but it appears to only serialize/deserialize the base class members. All of the derived message members are missing from the result.
Am I missing something? My application will require mixed message types.
FWIW I don't see any strings from the second derived type in the binary file, so I suspect the derived type members aren't being serialized.
Thanks, Greg
class Program
{
[DataContract(Name = "SideType", Namespace = "AvroMessage")]
public enum EventType
{
Unknown = 0,
One = 1,
Two = 2
}
[DataContract(Name = "MessageBase", Namespace = "AvroMessage")]
public class MessageBase
{
[DataMember(Name = "Subtype")]
public string Subtype;
[DataMember(Name = "Timestamp")]
public DateTime Timestamp;
[DataMember(Name = "GroupName")]
public string GroupName;
public override bool Equals(object obj)
{
MessageBase other = obj as MessageBase;
if (other == null) return false;
return Subtype == other.Subtype &&
Timestamp == other.Timestamp &&
GroupName == other.GroupName;
}
}
[DataContract(Name = "SubMessage1", Namespace = "AvroMessage")]
public class SubMessage1 : MessageBase
{
[DataMember(Name = "Volume")]
public int Volume;
[DataMember(Name = "Count")]
public int Count;
[DataMember(Name = "DetectedSide")]
public EventType Event;
public override bool Equals(object obj)
{
SubMessage1 other = obj as SubMessage1;
if (other == null) return false;
return Subtype == other.Subtype &&
Timestamp == other.Timestamp &&
GroupName == other.GroupName &&
Event == other.Event &&
Volume == other.Volume &&
Count == other.Count;
}
}
[DataContract(Name = "SubMessage2", Namespace = "AvroMessage")]
public class SubMessage2 : MessageBase
{
[DataMember(Name = "Name1")]
public string Name1;
[DataMember(Name = "Volume1")]
public int Volume1;
[DataMember(Name = "Name2")]
public string Name2;
[DataMember(Name = "Volume2")]
public int Volume2;
[DataMember(Name = "PriceMove")]
public double PriceMove;
public override bool Equals(object obj)
{
SubMessage2 other = obj as SubMessage2;
if (other == null) return false;
return Subtype == other.Subtype &&
Timestamp == other.Timestamp &&
GroupName == other.GroupName &&
Volume1 == other.Volume1 &&
Name1 == other.Name1 &&
Volume2 == other.Volume2 &&
Name2 == other.Name2 &&
PriceMove == other.PriceMove;
}
}
public class MessageFactory
{
public static IEnumerable<MessageBase> CreateMessages(int number)
{
Random ran = new Random();
List<MessageBase> retval = new List<MessageBase>();
for (int i = 0; i < number; i++)
{
if (ran.Next(2) == 0)
{
SubMessage1 sub1 = new SubMessage1();
sub1.Timestamp = DateTime.Now;
sub1.GroupName = "Group" + DateTime.Now.Millisecond.ToString();
sub1.Subtype = "SubMessag1";
sub1.Volume = ran.Next(10000);
sub1.Count = ran.Next(100);
if (ran.Next(2) == 0)
{
sub1.Event = EventType.One;
}
else
{
sub1.Event = EventType.Two;
}
retval.Add(sub1);
}
else
{
SubMessage2 sub2 = new SubMessage2();
sub2.Timestamp = DateTime.Now;
sub2.GroupName = "Group" + DateTime.Now.Millisecond.ToString();
sub2.Subtype = "SubMessag2";
sub2.Volume1 = ran.Next(1000);
sub2.PriceMove = ran.NextDouble() * 100 - 50;
sub2.Volume2 = ran.Next(1000);
sub2.Name1 = "Contract" + (DateTime.Now.Millisecond + ran.Next(5)).ToString();
sub2.Name2 = "Contract" + DateTime.Now.Millisecond.ToString();
retval.Add(sub2);
}
}
return retval;
}
}
public static void TestAvro(int count)
{
bool correct = false;
long serTicks = 0;
long deserTicks = 0;
Stopwatch sw = new Stopwatch();
sw.Reset();
var serializer = Microsoft.Hadoop.Avro.AvroSerializer.Create<MessageBase>();
MessageBase[] messages = new MessageBase[count];
using (var file = File.Create(#"C:\test_avro.bin"))
{
int i = 0;
foreach (var message in MessageFactory.CreateMessages(count))
{
messages[i++] = message;
sw.Start();
serializer.Serialize(file, message);
sw.Stop();
}
}
serTicks = sw.ElapsedTicks;
sw.Reset();
List<int> badMessages = new List<int>();
using (var file = File.OpenRead(#"C:\test_avro.bin"))
{
for (int i = 0; i < count; i++)
{
sw.Start();
MessageBase message = serializer.Deserialize(file);
sw.Stop();
SubMessage1 m1 = message as SubMessage1;
SubMessage2 m2 = message as SubMessage2;
bool areNull = (m1 == null) && (m2 == null); // Always true
if (!messages[i].Equals(message)) badMessages.Add(i);
}
}
deserTicks = sw.ElapsedTicks;
correct = badMessages.Count == 0;
long size = (new FileInfo(#"C:\test_proto.bin")).Length;
Console.WriteLine(String.Format("Correct: {0}, Time Out: {1}, , Time In: {2}, , Size: {3}", correct, serTicks, deserTicks, size));
}
static void Main(string[] args)
{
TestAvro(10000);
Console.ReadLine();
}
}
My bad - I forgot the KnownType attribute on the base class, one for each derived type. It works if you include the attributes.
I am trying to draw a list of all contacts saved in device. Everything is fine but when I select all contacts, I get only those contacts which are drawn on the screen. In other words, list drawing only those contacts which are visible on screen. To get the remaining contacts I have to scroll the list.
Here is my code:
public class CheckboxListField extends VerticalFieldManager implements ListFieldCallback, FieldChangeListener {
private static Vector selectedContacts ;
private ChecklistData[] mListData = new ChecklistData[] {};
private ListField mListField;
private static Vector mContacts;
private ContactList contactList;
private Enumeration allContacts;
private SendEmail sendEmail;
private boolean isChecked=false;
private BlackBerryContact contactItem;
private VerticalFieldManager _mainVFM = new VerticalFieldManager();
private int i;
private int j=0;
private String emails="";
private ButtonField _inviteButton;
private HorizontalFieldManager selectAllHFM;
private CustomButtonField selectAllButton;
private Bitmap _uncheckBmp;
private Bitmap _checkBmp;
private LabelField selectAllLabel;
private CheckboxField selectAllCheckBox;
private VerticalFieldManager contactListVFM;
private boolean listItemChecked=false;
private StringBuffer rowString;
private boolean getCBoxStatus;
// A class to hold the Strings in the CheckBox and it's checkbox state
// (checked or unchecked).
private class ChecklistData {
private String _stringVal;
private boolean _checked;
private String _telNumber;
ChecklistData(String stringVal, boolean checked) {
_stringVal = stringVal;
_checked = checked;
//_telNumber = telNumber;
}
// Get/set methods.
private String getStringVal() {
return _stringVal;
}
private boolean isChecked() {
return _checked;
}
// Toggle the checked status.
public void toggleChecked() {
_checked = !_checked;
}
}
public CheckboxListField() {
_mainVFM.add(createContactList(isChecked));
add(_mainVFM);
}
public VerticalFieldManager createContactList(boolean checked){
isChecked = checked;
selectedContacts = new Vector();
//INVITE BUTTON
contactListVFM = new VerticalFieldManager();
_inviteButton=new ButtonField("Invite Friend");
_inviteButton.setChangeListener(this);
_inviteButton.setMargin(2,0,10,0);
//SELECT ALL CHECKBOX
selectAllHFM = new HorizontalFieldManager();
_uncheckBmp = Bitmap.getBitmapResource("Uncheck.png");
_checkBmp = Bitmap.getBitmapResource("checked.png");
selectAllButton = new CustomButtonField(29, "", _uncheckBmp, _checkBmp, ButtonField.CONSUME_CLICK);
selectAllButton.setChangeListener(this);
selectAllButton.setMargin(5,5,5,5);
selectAllCheckBox = new CheckboxField("Select All", isChecked){
protected boolean navigationClick(int status,
int time) {
selectedContacts = new Vector();
emails = "";
boolean getCBoxStatus = selectAllCheckBox.getChecked();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
return true;
}
};
selectAllCheckBox.setChangeListener(this);
selectAllLabel = new LabelField("Select All");
selectAllLabel.setMargin(5,5,5,5);
selectAllHFM.add(selectAllCheckBox);
//selectAllHFM.add(selectAllLabel);
// toggle list field item on navigation click
mListField = new ListField() {
protected boolean navigationClick(int status,
int time) {
toggleItem();
return true;
};
};
// set two line row height
//mListField.setRowHeight(getFont().getHeight() * 2);
mListField.setCallback(this);
//contactListVFM.add(new NullField(NullField.FOCUSABLE));
contactListVFM.add(_inviteButton);
contactListVFM.add(selectAllHFM);
contactListVFM.add(new SeparatorField());
contactListVFM.add(mListField);
//LOAD CONTACTS
// load contacts in separate thread
loadContacts.run();
return contactListVFM;
}
protected Runnable loadContacts = new Runnable() {
public void run() {
reloadContactList();
// fill list field control in UI event thread
UiApplication.getUiApplication().invokeLater(
fillList);
}
};
protected Runnable fillList = new Runnable() {
public void run() {
int size = mContacts.size();
mListData = new ChecklistData[size];
for (int i =0; i < mContacts.size() ; i++) {
contactItem = (BlackBerryContact) mContacts
.elementAt(i);
String displayName = getDisplayName(contactItem);
// String telContact = getContact(item);
mListData[i] = new ChecklistData(
displayName, isChecked);
mListField.invalidate(i);
System.out.println(">>>>>>>>>"+mListData[i]);
}
mListField.setSize(size);
//invalidate();
}
};
protected void toggleItem() {
listItemChecked = true ;
selectAllCheckBox.setChecked(false);
listItemChecked =false ;
// Get the index of the selected row.
int index = mListField.getSelectedIndex();
System.out.println("..............."+index);
if (index != -1) {
// Get the ChecklistData for this row.
ChecklistData data = mListData[index];
// Toggle its status.
data.toggleChecked();
mListField.invalidate(index);
}
}
private boolean reloadContactList() {
try {
contactList = (ContactList) PIM
.getInstance()
.openPIMList(PIM.CONTACT_LIST,
PIM.READ_ONLY);
allContacts = contactList.items();
mContacts = enumToVector(allContacts);
mListField.setSize(mContacts.size());
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,>>>>>>>>>>"+mListField.getSize());
return true;
} catch (PIMException e) {
return false;
}
}
// Convert the list of contacts from an Enumeration to a Vector
private Vector enumToVector(Enumeration contactEnum) {
Vector v = new Vector();
if (contactEnum == null)
return v;
while (contactEnum.hasMoreElements()){
Contact contact = (Contact) allContacts.nextElement();
if(contactList.isSupportedField(Contact.EMAIL)&& (contact.countValues(Contact.EMAIL) > 0)) {
String emailID=contact.getString(Contact.EMAIL, 0);
if(emailID.length() !=0 && emailID != null ){
v.addElement(contact);
}
}
}
return v;
}
public void drawListRow(ListField list,
Graphics graphics, int index, int y, int w) {
rowString = new StringBuffer();
Object obj = this.get(list, index);
if (list.getSelectedIndex() != index) {
graphics.setBackgroundColor(index % 2 == 0 ||index==0 ? Color.WHITE
: Color.LIGHTGRAY);
graphics.clear();
//list.setFocus();
}
BlackBerryContact contact = (BlackBerryContact) mContacts
.elementAt(index);
String email= contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
if (obj != null) {
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
rowString
.append(Characters.BALLOT_BOX_WITH_CHECK);
} else {
selectedContacts.removeElement(email);
rowString.append(Characters.BALLOT_BOX);
}
// Append a couple spaces and the row's text.
rowString.append(Characters.SPACE);
rowString.append(Characters.SPACE);
rowString.append(currentRow.getStringVal());
// Draw the text.
}
graphics.drawText(rowString.toString(), 0, y,
0, w);
}
public static String getDisplayName(Contact contact) {
if (contact == null) {
return null;
}
String displayName = null;
// First, see if there is a meaningful name set for the contact.
if (contact.countValues(Contact.NAME) > 0) {
final String[] name = contact.getStringArray(
Contact.NAME, 0);
final String firstName = name[Contact.NAME_GIVEN];
final String lastName = name[Contact.NAME_FAMILY];
if (firstName != null && lastName != null) {
displayName = firstName + " " + lastName;
} else if (firstName != null) {
displayName = firstName;
} else if (lastName != null) {
displayName = lastName;
}
if (displayName != null) {
final String namePrefix = name[Contact.NAME_PREFIX];
if (namePrefix != null) {
displayName = namePrefix + " "
+ displayName;
}
return displayName;
}
}
return displayName;
}
// Returns the object at the specified index.
public Object get(ListField list, int index) {
Object result = null;
if (mListData.length > index) {
result = mListData[index];
}
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,"+mListData.length);
return result;
}
// Returns the first occurrence of the given String,
// beginning the search at index, and testing for
// equality using the equals method.
public int indexOfList(ListField list, String p, int s) {
return -1;
}
// Returns the screen width so the list uses the entire screen width.
public int getPreferredWidth(ListField list) {
return Graphics.getScreenWidth();
// return Display.getWidth();
}
public void fieldChanged(Field field, int context) {
if(field==_inviteButton){
for(int n=0 ; n<selectedContacts.size() ; n++){
emails= emails + selectedContacts.elementAt(n)+",";
}
//}
String mailBody =": "+Jxa.loginUserName+" invited you on NaijaPings app. Please download NaijaPings Android app from here "+"http://appworld.blackberry.com/webstore/content/77264/?lang=en" ;
sendEmail=new SendEmail(mailBody);
sendEmail.Email(emails,Constant.emailSubject);
emails ="" ;
selectedContacts.removeAllElements();
}else if(field == selectAllCheckBox){
selectedContacts = new Vector();
emails = "";
getCBoxStatus = selectAllCheckBox.getChecked();
//selectedContacts.removeAllElements();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
}
}
}
Here ,in drawListRow() , get() method is called only that many times that is number of contacts are visible on the screen. For remaining contact to add, I have to scroll the list.
In drawListRow() method I am adding those contacts into selectedContacts vector and than using those vector to get contact to send a mail. Contacts will be added only when particular list item will be drawn.
So, how I can get all selected contact without scrolling the list?
This is similar to the problem you had in one of your other recent questions. The problem is that drawListRow() is a callback designed to let you draw the rows that need drawing. It's not meant to do anything else, like assembling a list of contacts to email.
The BlackBerry OS tries to be efficient, so it will only ask you to drawListRow() for the rows that are actually visible to the user (on screen). Anything more would be wasteful.
So, if you want to assemble a list of all selected rows, you should do it somewhere else, not in drawListRow().
It looks to me like you can build a list of all currently selected rows by using this code, wherever you want:
public Vector getSelectedContacts() {
selectedContacts.removeAllElements();
for (int i = 0; i < mListData.length; i++) {
Object obj = mListData[i];
if (obj != null) {
BlackBerryContact contact = (BlackBerryContact) mContacts.elementAt(i);
String email = contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
} else {
// this line is probably not actually needed, since we
// call removeAllElements() at the start of this method
selectedContacts.removeElement(email);
}
}
}
return selectedContacts;
}
in my application i have a Custom text box with BasicEditField.FILTER_NUMERIC. When the user enter the value in the field the comma should be added to the Currency format .
EX:1,234,567,8.... like this.
In my code i tried like this.
protected boolean keyUp(int keycode, int time) {
String entireText = getText();
if (!entireText.equals(new String(""))) {
double val = Double.parseDouble(entireText);
String txt = Utile.formatNumber(val, 3, ",");// this will give the //comma separation format
setText(txt);// set the value in the text box
}
return super.keyUp(keycode, time);
}
it will give the correct number format... when i set the value in the text box it will through the IllegalArgumentException. I know BasicEditField.FILTER_NUMERIC will not allow the charector like comma(,)..
How can i achieve this?
I tried this way and it works fine...
public class MyTextfilter extends TextFilter {
private static TextFilter _tf = TextFilter.get(TextFilter.REAL_NUMERIC);
public char convert(char character, int status) {
char c = 0;
c = _tf.convert(character, status);
if (c != 0) {
return c;
}
return 0;
}
public boolean validate(char character) {
if (character == Characters.COMMA) {
return true;
}
boolean b = _tf.validate(character);
if (b) {
return true;
}
return false;
}
}
and call like this
editField.setFilter(new MyTextfilter());
I have added a BasicEditField to a GridFieldManager. When I test it, it allows input values like 11.11.11. How can I make my BasicEditField accept only correct double numbers, like 101.1 or 123.123. That is, allow only one decimal point.
gfm = new GridFieldManager(1, 2, 0);
gfm.add(new LabelField(" Enter value : "));
bef = new BasicEditField(BasicEditField.NO_NEWLINE|BasicEditField.FILTER_REAL_NUMERIC);
bef.setFilter(TextFilter.get(NumericTextFilter.REAL_NUMERIC));
bef.setFilter(TextFilter.get(TextFilter.REAL_NUMERIC));
bef.setText("1");
bef.setMaxSize(8);
gfm.add(bef);
add(gfm);
i had tried everything that i can. but the problem is yet in my app. can anyone give me a proper way to design a input field tha accepts decimal numbers?
Please add all the objects into the mainScreen with add(field);.
and then trying to get value of that fields.
now in your code put
String s = bef.getText();
Dialog.alert(s);
after
add(gfm);
and
To accept number like 1.1111.
then add
BasicEditField.FILTER_REAL_NUMERIC
in BasicEditFieldConstructor.
Now i think you got your solution.
finally i got the solution for a forum(forgot to copy the link)..
here it is...
inside my class i put the variables...
private int maxIntDigits = -1;
private int maxFractDigits = -1;
private String old;
i had added a BasicEditField, bef..
bef = new BasicEditField("","1");
bef.setMaxSize(8);
bef.setChangeListener(this);
add(bef);
And then in its fieldChanged().
public void fieldChanged(Field field, int context)
{
if(field==bef)
{
String str = bef.getText();
if(str.equals(""))
{
old = "";
//return;
}
if(str.indexOf('.') == str.lastIndexOf('.'))
{
if(str.indexOf('-') >= 0)
{
bef.setText(old);
}
if(validateIntPart(str) && validateFractPart(str))
{
old = str;
//return;
}
else
{
bef.setText(old);
}
}
else
{
bef.setText(old);
//return;
}
}
}
and then two functions in it...
private boolean validateIntPart(String str) {
if(maxIntDigits == -1) {
return true; //no limit has been set
}
int p = str.indexOf('.');
if(p == -1) {
p = str.length();
}
int digits = str.substring(0, p).length();
if(digits > maxIntDigits) {
return false;
} else {
return true;
}
}
private boolean validateFractPart(String str) {
if(maxFractDigits == -1) {
return true; //no limit has been set
}
int p = str.indexOf('.');
if(p == -1) {
return true; //if no '.' found then the fract part can't be too big
}
int digits = str.substring(p + 1, str.length()).length();
if(digits > maxFractDigits) {
return false;
} else {
return true;
}
}