how are static method calls handled by the JVM? does it still allocate memory when a call is made? if yes, how does garbage collection treat this allocation after the method call?
I need to split a text using the separator ". ". For example I want this string :
Washington is the U.S Capital. Barack is living there.
To be cut into two parts:
Washington is the U.S Capital.
Barack is living there.
Here is my code :
// Initialize the tokenizer
StringTokenizer tokenizer = new StringTokenizer("Washington is the U.S Capital. Barack is living there.", ". ");
while (tokenizer.hasMoreTokens()) {
System.out.println(tokenizer.nextToken());
}
And the output is unfortunately :
Washington
is
the
U
S
Capital
Barack
is
living
there
Can someone explain what's going on?
when looping, for instance:
for ( int j = 0; j < 1000; j++) {}; and I need to instantiate 1000 objects, how does it differ when I declare the object inside the loop from declaring it outside the loop ??
for ( int j = 0; j < 1000; j++) {Object obj; obj =}
vs
Object obj;
for ( int j = 0; j < 1000; j++) {obj =}
It's obvious that the object is accessible either only from the loop scope or from the scope that is surrounding it. But I don't understand the performance question, garbage collection etc.
What is the best practice ? Thank you
Here's what I am looking to accomplish, I have a class that has an enum of some values and I want to subclass that and add more values to the enum. This is a bad example, but:
public class Digits
{
public enum Digit
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
}
}
public class HexDigits extends Digits
{
public enum Digit
{
A, B, C, D, E, F
}
}
so that HexDigits.Digit contains all Hex Digits. Is that possible?
I have the following code in struts.xml:
<interceptor-ref name="checkTabsStack">
<param name="tabName">availability</param>
</interceptor-ref>
and I want to access the parameter tabName in the interceptor routine, how do i do that? i tried
Map params = ActionContext.getContext().getParameters();
but params comes empty...
Thanks!
I have written this piece of code to break an image into 9 pieces and it gives me runtime error. There is no error in LogCat and I am stuck. The error comes at line 7 line from bottom (Bitmap.createBitmap(...);).
public Bitmap[] getPieces(Bitmap bmp) {
Bitmap[] bmps = new Bitmap[9];
int width = bmp.getWidth();
int height = bmp.getHeight();
int rows = 3;
int cols = 3;
int cellHeight = height / rows;
int cellWidth = width / cols;
int piece = 0;
for (int x = 0; x <= width; x += cellWidth) {
for (int y = 0; y <= height; y += cellHeight) {
Bitmap b = Bitmap.createBitmap(bmp, x, y, cellWidth,
cellHeight, null, false);
bmps[piece] = b;
piece++;
}
}
return bmps;
}
hi,
need to convert a pdf file to a doc file. I found different type of example to generate pdf file but not got pdf to doc.
please help me in this regard with good example or source code or guideline.
i have installed open cms on my local machine and it perfectly works fine.
But in order to work it corre,ty it is mentioned that i have to modify the my.ini file and set max_alllowed_packed site to 32
I have done it and it works perfectly fine
but can i modify this file if i use a third party hosting provider for tomcat and mysql??
When I run the following code it triggers an error message. The error message is shown below the code.
What code changes, or changes to the image file, are needed to fix this error?
Help will be appreciated.
import java.awt.*;
import java.awt.datatransfer.*;
public class LoadToClipboard {
public static void main( String [] args ) {
Toolkit tolkit = Toolkit.getDefaultToolkit();
Clipboard clip = tolkit.getSystemClipboard();
clip.setContents( new ImageSelection( tolkit.getImage("StackOverflowLogo.png")) , null );
}
}
class ImageSelection implements Transferable {
private Image image;
public ImageSelection(Image image) {
this.image = image;
}
// Returns supported flavors
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[]{DataFlavor.imageFlavor};
}
// Returns true if flavor is supported
public boolean isDataFlavorSupported(DataFlavor flavor) {
return DataFlavor.imageFlavor.equals(flavor);
}
// Returns image
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException {
if (!DataFlavor.imageFlavor.equals(flavor)) {
throw new UnsupportedFlavorException(flavor);
}
return image;
}
}
Exception in thread "main" java.lang.IllegalArgumentException: Width (-1) and height (-1) cannot be <= 0 at
java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:999) at
sun.awt.datatransfer.DataTransferer.imageToStandardBytes(DataTransferer.java:1994) at
sun.awt.windows.WDataTransferer.imageToPlatformBytes(WDataTransferer.java:267) at
sun.awt.datatransfer.DataTransferer.translateTransferable(DataTransferer.java:1123) at
sun.awt.windows.WDataTransferer.translateTransferable(WDataTransferer.java:163) at
sun.awt.windows.WClipboard.setContentsNative(WClipboard.java:73) at
sun.awt.datatransfer.SunClipboard.setContents(SunClipboard.java:93) at
automateSignature.LoadToClipboard.main(LoadToClipboard.java:8)
I have tried to find a place in the code where width and height can be specified, but have not succeeded. I also examined the properties of the jpg file and the w and h are specified.enter code here
Right, this is from an older exam which i'm using to prepare my own exam in january. We are given the following method:
public static void Oorspronkelijk()
{
String bs = "Dit is een boodschap aan de wereld";
int max = -1;
char let = '*';
for (int i=0;i<bs.length();i++) {
int tel = 1;
for (int j=i+1;j<bs.length();j++) {
if (bs.charAt(j) == bs.charAt(i)) tel++;
}
if (tel > max) {
max = tel;
let = bs.charAt(i);
}
}
System.out.println(max + " keer " + let);
}
The questions are:
what is the output? - Since the code is just an algorithm to determine the most occuring character, the output is "6 keer " (6 times space)
What is the time complexity of this code?
Fairly sure it's O(n²), unless someone thinks otherwise?
Can you reduce the time complexity, and if so, how?
Well, you can. I've received some help already and managed to get the following code:
public static void Nieuw()
{
String bs = "Dit is een boodschap aan de wereld";
HashMap<Character, Integer> letters = new HashMap<Character, Integer>();
char max = bs.charAt(0);
for (int i=0;i<bs.length();i++) {
char let = bs.charAt(i);
if(!letters.containsKey(let)) {
letters.put(let,0);
}
int tel = letters.get(let)+1;
letters.put(let,tel);
if(letters.get(max)<tel) {
max = let;
}
}
System.out.println(letters.get(max) + " keer " + max);
}
However, I'm uncertain of the time complexity of this new code: Is it O(n) because you only use one for-loop, or does the fact we require the use of the HashMap's get methods make it O(n log n) ?
And if someone knows an even better way of reducing the time complexity, please do tell! :)
hi,
first time dealing with xml, so please be patient. the code below is probably evil in a million ways (I'd be very happy to hear about all of them), but the main problem is of course that it doesn't work :-)
public class Test {
private static final String JSDL_SCHEMA_URL = "http://schemas.ggf.org/jsdl/2005/11/jsdl";
private static final String JSDL_POSIX_APPLICATION_SCHEMA_URL = "http://schemas.ggf.org/jsdl/2005/11/jsdl-posix";
public static void main(String[] args) {
System.out.println(Test.createJSDLDescription("/bin/echo", "hello world"));
}
private static String createJSDLDescription(String execName, String args) {
Document jsdlJobDefinitionDocument = getJSDLJobDefinitionDocument();
String xmlString = null;
// create the elements
Element jobDescription = jsdlJobDefinitionDocument.createElement("JobDescription");
Element application = jsdlJobDefinitionDocument.createElement("Application");
Element posixApplication = jsdlJobDefinitionDocument.createElementNS(JSDL_POSIX_APPLICATION_SCHEMA_URL, "POSIXApplication");
Element executable = jsdlJobDefinitionDocument.createElement("Executable");
executable.setTextContent(execName);
Element argument = jsdlJobDefinitionDocument.createElement("Argument");
argument.setTextContent(args);
//join them into a tree
posixApplication.appendChild(executable);
posixApplication.appendChild(argument);
application.appendChild(posixApplication);
jobDescription.appendChild(application);
jsdlJobDefinitionDocument.getDocumentElement().appendChild(jobDescription);
DOMSource source = new DOMSource(jsdlJobDefinitionDocument);
validateXML(source);
try {
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StreamResult result = new StreamResult(new StringWriter());
transformer.transform(source, result);
xmlString = result.getWriter().toString();
} catch (Exception e) {
e.printStackTrace();
}
return xmlString;
}
private static Document getJSDLJobDefinitionDocument() {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = null;
try {
builder = factory.newDocumentBuilder();
} catch (Exception e) {
e.printStackTrace();
}
DOMImplementation domImpl = builder.getDOMImplementation();
Document theDocument = domImpl.createDocument(JSDL_SCHEMA_URL, "JobDefinition", null);
return theDocument;
}
private static void validateXML(DOMSource source) {
try {
URL schemaFile = new URL(JSDL_SCHEMA_URL);
Sche maFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
Schema schema = schemaFactory.newSchema(schemaFile);
Validator validator = schema.newValidator();
DOMResult result = new DOMResult();
validator.validate(source, result);
System.out.println("is valid");
} catch (Exception e) {
e.printStackTrace();
}
}
}
it spits out a somewhat odd message:
org.xml.sax.SAXParseException: cvc-complex-type.2.4.a: Invalid content was found starting with element 'JobDescription'. One of '{"http://schemas.ggf.org/jsdl/2005/11/jsdl":JobDescription}' is expected.
Where am I going wrong here?
Thanks a lot
<resource name="cde.xml" status="updated" isCollection="false">
<mediaType>xml</mediaType>
<creator>admin</creator>
<createdTime>1352783477964</createdTime>
<lastUpdater>admin</lastUpdater>
<lastModified>1352783477964</lastModified>
<description />
<version>0</version>
<content>ZGFza2QgbGQgbGt2Zmx3ZGFzamQgYWRsa2ogYWxramRrbGEgamQK
</content>
</resource>
i want to catch nodes which are having status using xpath here is the xpath expression other part of the code is correct. I have problem with xpath expression
AXIOMXPath xpathExpression = new AXIOMXPath ( "//resourse[@name]");
I am a building a console Sudoku Solver where the main objective is raw speed.
I now have a ManagerThread that starts WorkerThreads to compute the neibhbors of each cell. So one WorkerThread is started for each cell right now. How can I re-use an existing thread that has completed its work?
The Thread Pool Pattern seems to be the solution, but I don't understand what to do to prevent the thread from dying once its job has been completed.
ps : I do not expect to gain much performance for this particular task, just want to experiment how multi-threading works before applying it to the more complex parts of the code.
Thanks
Setup:
64bit Linux
64bit SUN Jvm 1.6.0_20
Weblogic 10.3
Is it possible to run Weblogic 10.3 in this setup with a maximum heap size of 8gb? We have recived answers from oracle support that states that it might not be possible to address more than 4gb with this setup.
Please submit any official links that support any statements that it is possible to run this setup with more than 4gb of heap size. We can not find any documentation of any limits of heap size when running with this setup.
Thanx
I'm trying to make a program that uploads a image to a webserver that accepts multipart file-uploads.
More specificly i want to make a http POST request to http://iqs.me that sends a file in the variable "pic".
I've made a lot of tries but i don't know if i've even been close. The hardest part seems to be to get a HttpURLConnection to make a request of the type POST. The response i get looks like it makes a GET.
(And i want to do this without any third party libs)
UPDATE: non-working code goes here (no errors but doesn't seem to do a POST):
HttpURLConnection conn = null;
BufferedReader br = null;
DataOutputStream dos = null;
DataInputStream inStream = null;
InputStream is = null;
OutputStream os = null;
boolean ret = false;
String StrMessage = "";
String exsistingFileName = "myScreenShot.png";
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;
String responseFromServer = "";
String urlString = "http://iqs.local.com/index.php";
try{
FileInputStream fileInputStream = new FileInputStream( new File(exsistingFileName) );
URL url = new URL(urlString);
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setUseCaches(false);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
dos = new DataOutputStream( conn.getOutputStream() );
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"pic\";" + " filename=\"" + exsistingFileName +"\"" + lineEnd);
dos.writeBytes(lineEnd);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0){
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
fileInputStream.close();
dos.flush();
dos.close();
}catch (MalformedURLException ex){
System.out.println("Error:"+ex);
}catch (IOException ioe){
System.out.println("Error:"+ioe);
}
try{
inStream = new DataInputStream ( conn.getInputStream() );
String str;
while (( str = inStream.readLine()) != null){
System.out.println(str);
}
inStream.close();
}catch (IOException ioex){
System.out.println("Error: "+ioex);
}
Talking about the org.w3c.dom package;
When I call Node.cloneNode() method from a Element(extends Node) object, which Document is used to create the new cloned Element?
Example:
import org.w3c.dom;
class MyClass {
public static void main(String[] args) throws Exception {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = builder.newDocument();
Element element = doc.createElement("myElement");
Element cloneElement = (Element) element.cloneNode(true);
}
}
Which Document was used to create cloneElement?
I have created a servlet which displays a form having some fields and a submit button and also created a web service having methods which are needed in my servlet.
I have deployed the web service on Tomcat 5.5.9/Axis and servlet web application on Tomcat ( same instance of Tomcat) using eclipse. Since one is web service and other is web application both are running on separate instances of tomcat, so when i run them separately i.e servlet without the call to web service and a client that access that webservice it works fine but when i integrate them both i get a error like
exception: javax.servlet.ServletException
I would like to call the web service and return the result when i press the button
Please advice me on how to implement that.
Recently i've found myself writing a lot of methods with what i can only think to call debugging scaffolding. Here's an example:
public static void printArray (String[] array, boolean bug)
{
for (int i = 0; i<array.lenght; i++)
{
if (bug) System.out.print (i) ; //this line is what i'm calling the debugging scaffolding i guess.
System.out.println(array[i]) ;
}
}
in this method if i set bug to true, wherever its being called from maybe by some kind of user imput, then i get the special debugging text to let me know what index the string being printed as at just in case i needed to know for the sake of my debugging (pretend a state of affairs exists where its helpful).
All of my questions more or less boil down to the question: is this a good idea? but with a tad bit more objectivity:
Is this an effective way to test my
methods and debug them? i mean effective in terms of efficiency and not messing up my code.
Is it acceptable to leave the if
(bug) stuff ; code in place after
i've got my method up and working?
(if a definition of "acceptability"
is needed to make this question
objective then use "is not a matter
of programing controversy such as
ommiting brackets in an if(boolean)
with only one line after it, though
if you've got something better go
ahead and use your definition i won't
mind)
Is there a more effective way to
accomplish the gole of making
debugging easier than what i'm doing?
Anything you know i mean to ask but
that i have forgotten too (as much
information as makes sense is
appreciated).
I would like to know what is the best, fastest and easiest way to compare between 2-dimension arrays of integer.
the length of arrays is the same. (one of the array's is temporary array)
thanks.
Lets say that I have the following code:
public class Shelter<A extends Animal, B extends Animal>
{
List<A> topFloor = new Vector<A>();
List<B> bottomFloor = new Vector<B>();
public A getFirstTopFloorAnimal(){return topFloor.firstElement();}
public B getFirstBottomFloorAnimal(){return bottomFloor.firstElement();}
//This compiles but when I try to use it, it only returns objects
public List<Animal> getAnimals()
{
Vector a = new Vector(topFloor);
a.addAll(bottomFloor);
return a;
}
}
Now for somereason the following code compiles. But when I try to use getAnimals() I get a of objects instead of Animal. Any ideas why this is? Does this have to do with the List is NOT a List idea in the Generics tutorial?
Thank you.