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  • How to validate overlapping no in java

    - by anandhinaveen
    I Have dynamically render row. WE have fields like FROM TO. For eg: From TO 2 10, 2 3, 8 12 It cannot accept this combination row.. That means no number should be overlapping. For eg: From TO 2 10, 0 1, 11 12 This combination is allowed.the row may also increased. I need need to write a validation for this overlapping. Can any 1 help to solve this problem.

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  • Java syntax of +

    - by Pindatjuh
    Why is the following syntax correct: x = y+++y; (Where it means y++ + y or y + ++y which both mean y * 2 + 1) But this is not valid syntax: x = y+++++y; (Which should mean y++ + ++y, which must mean y and increase y and then add ++y which increases y thus y * 2 + 2) Is there a reason for this?

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  • Get file full path in java

    - by c0mrade
    When I pass File file to a method I'm trying to get its full path like file.getAbsolutePath(); I always get the same result no matter which one I use either absolute or canonical path PATH_TO_MY_WORKSPACE/projectName/filename and it is not there, how can I get exact location of the file? Thank you

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  • loading an image from a package in Java (JFrame)

    - by Shahar Kazaz
    i'm having a problem loading an image from a package i created in the project that was set to contain images, i have to write the whole picture location in the computer instead of just the package that contains it. i've tried several things but nothing seams to work... where is the command i use to load the image : searchBar = ImageIO.read(new File("C:\\Users\\ASUS\\Documents\\NetBeansProjects\\Project\\src\\Images\\search.jpg")); "Images" is a package in my project , this works, but when i try loading the image without the "C:\..." only with the "\Images..." it doesn't , so i have to change it every time i open this project in another computer. hopefully one of u has the answer for me , thanks in advance for any answer :)

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  • replace \n and \r\n with <br /> in java

    - by Bala R
    This has been asked several times for several languages but I can't get it to work. I have a string like this String str = "This is a string.\nThis is a long string."; And I'm trying to replace the \n with <br /> using str = str.replaceAll("(\r\n|\n)", "<br />"); but the \n is not getting replaced. I tried to use this RegEx Tool to verify and I see the same result. The input string does not have a match for "(\r\n|\n)". What am i doing wrong ?

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  • Slowing process creation under Java?

    - by oconnor0
    I have a single, large heap (up to 240GB, though in the 20-40GB range for most of this phase of execution) JVM [1] running under Linux [2] on a server with 24 cores. We have tens of thousands of objects that have to be processed by an external executable & then load the data created by those executables back into the JVM. Each executable produces about half a megabyte of data (on disk) that when read right in, after the process finishes, is, of course, larger. Our first implementation was to have each executable handle only a single object. This involved the spawning of twice as many executables as we had objects (since we called a shell script that called the executable). Our CPU utilization would start off high, but not necessarily 100%, and slowly worsen. As we began measuring to see what was happening we noticed that the process creation time [3] continually slows. While starting at sub-second times it would eventually grow to take a minute or more. The actual processing done by the executable usually takes less than 10 seconds. Next we changed the executable to take a list of objects to process in an attempt to reduce the number of processes created. With batch sizes of a few hundred (~1% of our current sample size), the process creation times start out around 2 seconds & grow to around 5-6 seconds. Basically, why is it taking so long to create these processes as execution continues? [1] Oracle JDK 1.6.0_22 [2] Red Hat Enterprise Linux Advanced Platform 5.3, Linux kernel 2.6.18-194.26.1.el5 #1 SMP [3] Creation of the ProcessBuilder object, redirecting the error stream, and starting it.

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  • Java generic Interface performance

    - by halfwarp
    Simple question, but tricky answer I guess. Does using Generic Interfaces hurts performance? Example: public interface Stuff<T> { void hello(T var); } vs public interface Stuff { void hello(Integer var); <---- Integer used just as an example } My first thought is that it doesn't. Generics are just part of the language and the compiler will optimize it as though there were no generics (at least in this particular case of generic interfaces). Is this correct?

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  • Java Swing Visual Editor HELP please

    - by bat
    How would i call this function in my main? private JFrame getMainpageframe1() { if (mainpageframe1 == null) { mainpageframe1 = new JFrame(); mainpageframe1.setSize(new Dimension(315, 306)); mainpageframe1.setContentPane(getMainpage()); mainpageframe1.setTitle("Shopping For Less: Main Page"); mainpageframe1.setVisible(true); mainpageframe1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } return mainpageframe1; } public static void main(String[] args) { //call that function to output the JFrame? } thanks

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  • Executing in java code an external program that takes arguments

    - by rmaster
    Process p; String line; String path; String[] params = new String [3]; params[0] = "D:\\prog.exe"; params[1] = picA+".jpg"; params[2] = picB+".jpg"; try { p = Runtime.getRuntime().exec(params); BufferedReader input = new BufferedReader (new InputStreamReader(p.getInputStream())); while ((line = input.readLine()) != null) System.out.println(line); input.close(); } catch (IOException e) {System.out.println(" procccess not read"+e);} i don't get any error, just nothing in cmd.exe prog.exe is working fine What to improve in order to make this code working?

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  • 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

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  • Problem in arranging contents of Class in JAVA

    - by LuckySlevin
    Hi, I have some classes and I'm trying to fill the objects of this class. Here is what i've tried. (Question is at the below) public class Team { private String clubName; private String preName; private ArrayList<String> branches; public Team(String clubName, String preName) { this.clubName = clubName; this.preName = preName; branches = new ArrayList<String>(); } public Team() { // TODO Auto-generated constructor stub } public String getClubName() { return clubName; } public String getPreName() { return preName; } public ArrayList<String> getBranches() { return branches; } public void setClubName(String clubName) { this.clubName = clubName; } public void setPreName(String preName) { this.preName = preName; } public void setBranches(ArrayList<String> branches) { this.branches = branches; } } public class Branch { private ArrayList<Player> players = new ArrayList<Player>(); String brName; public Branch() {} public void setBr(String brName){this.brName = brName;} public String getBr(){return brName;} public ArrayList<Player> getPlayers() { return players; } public void setPlayers(ArrayList<Player> players) { this.players = players; } } //TEST CLASS public class test { /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException { String a,b,c; String q = "q"; int brCount = 0, tCount = 0; BufferedReader input = new BufferedReader(new InputStreamReader(System.in)); Team[] teams = new Team[30]; Branch[] myBranch = new Branch[30]; for(int z = 0 ; z <30 ;z++) { teams[z] = new Team(); myBranch[z] = new Branch(); } ArrayList<String> tmp = new ArrayList<String>(); int k = 0; int secim = Integer.parseInt(input.readLine()); while(secim != 0) { if(k!=0) secim = Integer.parseInt(input.readLine()); k++; switch(secim) { case 1 : brCount = 0; a = input.readLine(); teams[tCount].setClubName(a); b= input.readLine(); teams[tCount].setPreName(b); c = input.readLine(); while(c.equals(q) == false) { if(brCount != 0) {c = input.readLine();} if(c.equals(q)== false){ myBranch[brCount].brName = c; tmp.add(myBranch[brCount].brName); brCount++; } System.out.println(brCount); } teams[tCount].setBranches(tmp); for(int i=0;i<=tCount;i++ ){ System.out.print("a :" + teams[i].getClubName()+ " " + teams[i].getPreName()+ " "); System.out.println(teams[i].getBranches());} tCount++; break; case 2: String src = input.readLine();//LATERRRRRRRr } } } } The problem is one of my class elements. I have an arraylist as an element of a class. When i enter: AAA as preName BBB as clubName c d e as Branches Then as a second element www as preName GGG as clubName a b as branches The result is coming like: AAA BBB c,d,e,a,b GGG www c,d,e,a,b Which means ArrayList part of the class is putting it on and on. I tried to use clear() method but caused problems. Any ideas.

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  • Problems reading text file data in Java

    - by user1828401
    I have this code: BufferedReader br =new BufferedReader(new FileReader("userdetails.txt")); String str; ArrayList<String> stringList = new ArrayList<String>(); while ((str=br.readLine())!=null){ String datavalue [] = str.split(","); String category = datavalue[0]; String value = datavalue[1]; stringList.add(category); stringList.add(value); } br.close(); it works when the variables category and value do not have a comma(,),however the values in the variable value does contain commas.Is there a way that I can split the index of the without using comma?

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  • formatting and converting in java

    - by mike_hornbeck
    I have few small basic problems : How to format : int i = 456; to give output : ""00000456" ? I've tried %08d but it's not working. Next thing is a problem with conversion and then formatting. I have side and height of triangle, let's say int's 4,7, and 7 is the height. From formula for field we know that F=1/2(a*h). So how to get F as float, with precision up to 10 places ? float f = a*h; works fine, but multiplying it by 0.5 gives error and by 1/2 returns 0.

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  • Java iterative vs recursive

    - by user1389813
    Can anyone explain why the following recursive method is faster than the iterative one (Both are doing it string concatenation) ? Isn't the iterative approach suppose to beat up the recursive one ? plus each recursive call adds a new layer on top of the stack which can be very space inefficient. private static void string_concat(StringBuilder sb, int count){ if(count >= 9999) return; string_concat(sb.append(count), count+1); } public static void main(String [] arg){ long s = System.currentTimeMillis(); StringBuilder sb = new StringBuilder(); for(int i = 0; i < 9999; i++){ sb.append(i); } System.out.println(System.currentTimeMillis()-s); s = System.currentTimeMillis(); string_concat(new StringBuilder(),0); System.out.println(System.currentTimeMillis()-s); } I ran the program multiple time, and the recursive one always ends up 3-4 times faster than the iterative one. What could be the main reason there that is causing the iterative one slower ?

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  • 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..

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  • java threads don't see shared boolean changes

    - by andymur
    Here the code class Aux implements Runnable { private Boolean isOn = false; private String statusMessage; private final Object lock; public Aux(String message, Object lock) { this.lock = lock; this.statusMessage = message; } @Override public void run() { for (;;) { synchronized (lock) { if (isOn && "left".equals(this.statusMessage)) { isOn = false; System.out.println(statusMessage); } else if (!isOn && "right".equals(this.statusMessage)) { isOn = true; System.out.println(statusMessage); } if ("left".equals(this.statusMessage)) { System.out.println("left " + isOn); } } } } } public class Question { public static void main(String [] args) { Object lock = new Object(); new Thread(new Aux("left", lock)).start(); new Thread(new Aux("right", lock)).start(); } } In this code I expect to see: left, right, left right and so on, but when Thread with "left" message changes isOn to false, Thread with "right" message don't see it and I get ("right true" and "left false" console messages), left thread don't get isOn in true, but right Thread can't change it cause it always see old isOn value (true). When i add volatile modifier to isOn nothing changes, but if I change isOn to some class with boolean field and change this field then threads are see changes and it works fine Thanks in advance.

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