Search Results

Search found 32961 results on 1319 pages for 'java'.

Page 316/1319 | < Previous Page | 312 313 314 315 316 317 318 319 320 321 322 323  | Next Page >

  • synchronizing reads to a java collection

    - by jeff
    so i want to have an arraylist that stores a series of stock quotes. but i keep track of bid price, ask price and last price for each. of course at any time, the bid ask or last of a given stock can change. i have one thread that updates the prices and one that reads them. i want to make sure that when reading no other thread is updating a price. so i looked at synchronized collection. but that seems to only prevent reading while another thread is adding or deleting an entry to the arraylist. so now i'm onto the wrapper approach: public class Qte_List { private final ArrayList<Qte> the_list; public void UpdateBid(String p_sym, double p_bid){ synchronized (the_list){ Qte q = Qte.FindBySym(the_list, p_sym); q.bid=p_bid;} } public double ReadBid(String p_sym){ synchronized (the_list){ Qte q = Qte.FindBySym(the_list, p_sym); return q.bid;} } so what i want to accomplish with this is only one thread can be doing anything - reading or updating an the_list's contents - at one time. am i approach this right? thanks.

    Read the article

  • Java: Converting UTF 8 to String

    - by kujawk
    When I run the following program: public static void main(String args[]) throws Exception { byte str[] = {(byte)0xEC, (byte)0x96, (byte)0xB4}; String s = new String(str, "UTF-8"); } on Linux and inspect the value of s in jdb, I correctly get: s = "ì–´" on Windows, I incorrectly get: s = "?" My byte sequence is a valid UTF-8 character in Korean, why would it be producing two very different results?

    Read the article

  • Simple Array in java

    - by user1311590
    I need to create the following in my main method. Create an array of size 100 doubles. write a loop to sotr the number 150.0 - 249.0 in the 100 location. public class Lab6_2 { public static void main(String[] args) { double[] values; values = new double [100]; double i = 0; for(double i = 150.0; i<249.0;i++){ System.out.println(values[99]); } } }

    Read the article

  • what databases can be used with java?

    - by aadersh patel
    I am doing an undergrad final project, and need to justify my choice of MySQL for the database element of my project. Truth is, it's the only one I can really use, and hence I went for it. What other database systems could I have used? Any advantages and disadvantages of these over MySQL?

    Read the article

  • Secure Desktop Mode effect for java application

    - by Aiden Strydom
    Does anyone now how to achieve a "Secure-Desktop Mode" (effect) such as one gets from the Windows Vista/7 UAC consent-blocks? I assume it is some function which will remove pixels here-and-there (and possibly graying them) and then finally drawing that to screen... I would like to apply it to my application to keep the user from doing anything until the another user connects to the system (but that is besides the point) I would really appreciate the advise. Kind regards A EDIT: i was really only looking for this graphicsFX.setColor(new Color(0, 0, 0, 0.8f)); graphicsFX.fillRect(0, 0, 800, 600); the defering of input i can do quite well... Thanks for all....

    Read the article

  • Java reading files......

    - by user69514
    Ok this is a homework questions, but I cannot find the answer anywhere, not even in the book. Path to Files If the user wants to specify a path for a file, the typical forward slash is replaced by ________. can you help?

    Read the article

  • Parsing XML with XPath in Java

    - by Mg
    I have a XML with a structure similar to this: <category> <subCategoryList> <category> </category> <category> <!--and so on --> </category> </subCategoryList> </category> I have a Category class that has a subcategory list (List<Category>). I'm trying to parse this XML file with XPath, but I can't get the child categories of a category. How can I do this with XPath? is there a better way to do this? Thanks in advance.

    Read the article

  • java.lang.NumberFormatException: unable to parse '' as integer one more time

    - by Quzziy
    I will take two numbers from user, but this number from EditText must be converted to int. I think it should be working, but I still have problem with compilation code in Android Studio. CatLog show error in line with: int wiek = Integer.parseInt(wiekEditText.getText().toString()); Below is my full Android code: public class MyActivity extends ActionBarActivity { int Wynik; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); int Tmax, RT; EditText wiekEditText = (EditText) findViewById(R.id.inWiek); EditText tspoczEditText = (EditText) findViewById(R.id.inTspocz); int wiek = Integer.parseInt(wiekEditText.getText().toString()); int tspocz = Integer.parseInt(tspoczEditText.getText().toString()); Tmax = 220 - wiek; RT = Tmax - tspocz; Wynik = 70*RT/100 + tspocz; final EditText tempWiekEdit = wiekEditText; TabHost tabHost = (TabHost) findViewById(R.id.tabHost); //Do TabHost'a z layoutu tabHost.setup(); TabHost.TabSpec tabSpec = tabHost.newTabSpec("Calc"); tabSpec.setContent(R.id.Calc); tabSpec.setIndicator("Calc"); tabHost.addTab(tabSpec); tabSpec = tabHost.newTabSpec("Hints"); tabSpec.setContent(R.id.Hints); tabSpec.setIndicator("Hints"); tabHost.addTab(tabSpec); final Button Btn = (Button) findViewById(R.id.Btn); Btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(),"blablabla"+ "Wynik",Toast.LENGTH_SHORT).show(); } }); wiekEditText.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { Btn.setEnabled(!(tempWiekEdit.getText().toString().trim().isEmpty())); } @Override public void afterTextChanged(Editable s) { } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.my, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }

    Read the article

  • Negative look ahead java

    - by venu
    I need an expression to capture a string like this "A"[A string that is NOT atleast 5 and atmost 6 digits]"B", In other words capture anything that is NOT the following A[0-9][0-9][0-9][0-9][0-9]B A[0-9][0-9][0-9][0-9][0-9][0-9]B I have tried the negative look ahead regex = "a((?![0-9]{5,6}).)*d" ; But it fails to capture all scenarios. Please help venu

    Read the article

  • Memory increases with Java UDP Server

    - by Trevor
    I have a simple UDP server that creates a new thread for processing incoming data. While testing it by sending about 100 packets/second I notice that it's memory usage continues to increase. Is there any leak evident from my code below? Here is the code for the server. public class UDPServer { public static void main(String[] args) { UDPServer server = new UDPServer(15001); server.start(); } private int port; public UDPServer(int port) { this.port = port; } public void start() { try { DatagramSocket ss = new DatagramSocket(this.port); while(true) { byte[] data = new byte[1412]; DatagramPacket receivePacket = new DatagramPacket(data, data.length); ss.receive(receivePacket); new DataHandler(receivePacket.getData()).start(); } } catch (IOException e) { e.printStackTrace(); } } } Here is the code for the new thread that processes the data. For now, the run() method doesn't do anything. public class DataHandler extends Thread { private byte[] data; public DataHandler(byte[] data) { this.data = data; } @Override public void run() { System.out.println("run"); } }

    Read the article

  • Java loop to collect the second and third elements every three in an array

    - by mhollander38
    I have a file with data in the form timestamp, coordinate, coordinate, seperated by spaces, as here; 14:25:01.215 370.0 333.0 I need to loop through and add the coordinates only to an array. The data from the file is read in and put into as String[] called info, from split(" "). I have two problems, I think the end of the file has a extra " " which I need to lose appropriately and I also want confirmation/suggestions of my loop, at the moment I am getting sporadic out of bounds exceptions. My loop is as follows; String[] info; info = dataHolder.split(" "); ArrayList<String> coOrds1 = new ArrayList<String>(); for (int counter = 0; counter < info.length; counter = counter+3) { coOrds1.add(info[counter+1]); coOrds1.add(info[counter+2]); } Help and suggestions appreciated. The text file is here but the class receives in a UDP packet from another class so I am unsure if this potentially adds " " at the end or not.

    Read the article

  • Java - A better to run code for a period of time

    - by mhollander38
    I need to run some code for a predefined length of time, when the time is up it needs to stop. Currently I am using a TimerTask to allow the code to execute for a set amount of time but this is causing endless threads to be created by the code and is just simply not efficient. Is there a better alternative? Current code; // Calculate the new lines to draw Timer timer3 = new Timer(); timer3.schedule(new TimerTask(){ public void run(){ ArrayList<String> Coords = new ArrayList<String>(); int x = Float.valueOf(lastFour[0]).intValue(); int y = Float.valueOf(lastFour[1]).intValue(); int x1 = Float.valueOf(lastFour[2]).intValue(); int y1 = Float.valueOf(lastFour[3]).intValue(); //Could be the wrong way round (x1,y1,x,y)? Coords = CoordFiller.coordFillCalc(x, y, x1, y1); String newCoOrds = ""; for (int j = 0; j < Coords.size(); j++) { newCoOrds += Coords.get(j) + " "; } newCoOrds.trim(); ClientStorage.storeAmmendedMotion(newCoOrds); } } ,time);

    Read the article

  • Returning string in java using 3 parameters

    - by user2905118
    Need to write a method describePerson() that takes 3 parameters, a String giving a person’s name, a boolean indicating their gender (true for female, false for male), and an integer giving their age. The method should return a String formatted as in the following examples: Lark is female. She is 2 years old. Or Jay is male. He is 1 year old. I am not sure how to write it correctly (my code): int describePerson(String name, boolean gender, int age) { String words=""; if(gender==true) return (name + "is "+gender+". "+"She is"+age+ "years old.); else return (name + "is "+gender+". "+"She is"+age+ "years old.); } The outcome "year" and "years" is also differs, but i don't know how to make it correct..

    Read the article

  • Java Hibernate session delete of object

    - by user2535201
    I'm really struggling with hibernate sessions, I never have the result I expect when making a query on a modified session object. I think all my problems are related. The last one is the following : final Session iSession = AbstractDAO.getSessionFactory().openSession(); try { iSession.beginTransaction(); MyObject iObject = DAOMyObject.getInstance().get(iSession,ObjectId); iObject.setQuantity(0); //previously the quantity was different from zero DAOMyObject.getInstance().update(iSession,iObject); DAOMyObject.getInstance().deleteObjectWithZeroQuantities(iSession); iSession.getTransaction().commit(); } catch (final Exception aException) { iSession.getTransaction().rollback(); logger.error(aException.getMessage(), aException); throw aException; } finally { iSession.close(); } What I'm not getting is why the object is not deleted, since I'm modified it in the session, the query making the delete should find it. I had the same problem with creating an object with an incremental id in a session, then creating another one in the same session before the commit, with a select max(id)+1. But the session gets me the same number of id every time.

    Read the article

  • Java Matrix Transpose strangeness going on

    - by user1459976
    ok so im making my own Matrix class. and i have a transpose method that transposes a matrix. this is the block in the main method Matrix m1 = new Matrix(4,2); m1.fillMatrix(1,2,3,4,5,6,7,8); System.out.println("before " + m1.toString()); m1.transpose(); System.out.println("after " + m1.toString()); this is where it gets messed up, at m1.transpose(); in the transpose() method public Matrix transpose() { if(isMatrix2) { Matrix tempMatrix = new Matrix(row, col); // matrix2 contents are emptied once this line is executed for(int i=0; i < row; i++) { for(int j=0; j < col; j++) tempMatrix.matrix2[i][j] = matrix2[i][j]; } so for some reason, the tempMatrix.matrix2 has the same id as this.matrix2. so when the codes executes Matrix tempMatrix = new Matrix(row,col); then the contents of this.matrix2 is emptied. anyone know what might be going on here?

    Read the article

  • Promoting letters in a string to the next letter in java

    - by CSD1988
    I'm having issues figuring out how to get my code to increment the string that is given by user input so that when a user chooses to replace a letter like z it would go to a, b to c ect. The catch is I have to do this without using boolean. I am supposed to get this by using arithmetics to get the promotion from z to a from the users input. Plus must be only lower case letters from a-z. Any help would be appreciated thanks.

    Read the article

  • Is there a faster method to match an arbitrary String to month name in Java

    - by jonc
    Hello, I want to determine if a string is the name of a month and I want to do it relatively quickly. The function that is currently stuck in my brain is something like: boolean isaMonth( String str ) { String[] months = DateFormatSymbols.getInstance().getMonths(); String[] shortMonths = DateFormatSymbols.getInstance().getShortMonths(); int i; for( i = 0; i<months.length(); ++i;) { if( months[i].equals(str) ) return true; if( shortMonths[i].equals(str ) return true; } return false; } However, I will be processing lots of text, passed one string at a time to this function, and most of the time I will be getting the worst case of going through the entire loop and returning false. I saw another question that talked about a Regex to match a month name and a year which could be adapted for this situation. Would the Regex be faster? Is there any other solution that might be faster?

    Read the article

  • Java Object Array item to String Array

    - by user341264
    Say I have the following: Class myclass { public string stra ="", strb = "" myclass(String a, String b){stra=a;strb=b} } //then in the app I want to do: myclass myclassinst1 = new myclass("blah","xxxx"); myclass myclassinst2 = new myclass("blah2","yyyy"); myclass myclassinst3 = new myclass("blah3","zzzz"); list <myclass> mylist = new ArrayList<myclass>(); mylist.add(myclassinst1 ); mylist.add(myclassinst2 ); mylist.add(myclassinst3 ); //How would I then convert that to a String[] Array of all the stra elements without using a loop. //eg: String[] strarr_a = mylist.toarray(myclass.stra); String[] strarr_b = mylist.toarray(myclass.strb); //instead of having to do String[] strarr_a = new String[mylist.size()]; String[] strarr_b = new String[mylist.size()]; for (int i=0;i<mylist.size();i++) { strarr_a[i] = mylist.get(i).stra; strarr_b[i] = mylist.get(i).strb; }

    Read the article

  • Help making a button open another app with Java/Android

    - by user569503
    I am trying to learn to make a simple app that opens a couple of other apps to eliminate the need for another apps. I just can't figure it out. From reading here and other places it seems this should work. Button batteryhistory = (Button)findViewById(R.string.BatteryHistoryButtonDialog); batteryhistory.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent i = new Intent(); ComponentName n = new ComponentName("com.android.settings", "com.android.settings.BatteryHistory"); i.setComponent(n); startActivity(i); Thanks so much for the help :D

    Read the article

  • Java Script JQUery

    - by windi
    Hi I am extracting data from an xml file converting it into json and rendering the images which i am retriving to the html file via jtemplate.now i want to user scroller and scroll the images .i can call to the scroller plugin but it is not scrolling throuhg . can any one help me please.

    Read the article

  • Validate a statment from string in JAVA

    - by Adnan
    I have a string; String allIn = "(50 > 100) AND (85< 100)"; Now I need to evaluate if the conditions inside are TRUE or FALSE, how can I do it? In real the string will be a value from a field in my DB, where I will substitute different values and they will form a string as shown above.

    Read the article

< Previous Page | 312 313 314 315 316 317 318 319 320 321 322 323  | Next Page >