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Both Double and Float support the longValue() method which will return you a long primitive (if it's in the range of long). The other option for bit manipulation is to use the toHexString() method on Double or Float .
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This may be a dumb question but what does bit shifting have to do with serialization? Why would you need to shift the bits in a double value in order to send it over a stream?
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I think the OP is getting confused with the stream operators of C++.
I must get a clever new signature for 2011.
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I'm assuming that you want to use the bit-representation of the floating point value with the shift operators to create a float from a byte-stream, and vice-versa
The java Float class (here[^]) contains functions:
floatToIntBits , floatToRawIntBits -- Convert from a float to an integer containing the float value's bit representation
intBitsToFloat : Converts an integer value (containing a float value's bit representation) to a Float variable.
So basically you can do something like:
byte[] data = ...;
int rdInt = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
float rdFloat = Float.intBitsToFloat(rdInt);
... And do the opposite to convert back from float to bytes.
"It was when I found out I could make mistakes that I knew I was on to something."
-Ornette Coleman
"Philosophy is a study that lets us be unhappy more intelligently."
-Anon.
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Hi,
I installed Netbeans 6.9 and try to work on Java. at first glance I faced 2 questions?
when you open new project you see Java and java EE. what is the problem between them? what the meaning of enterprise Application?
I would please if some one who has experience help me in this matter.
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Try the Java home page for more information on the different versions.
I must get a clever new signature for 2011.
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'at a glance' is the keyword: Java EE at a glance[^]
Java EE @ Wikipedia[^]
So a Java-Project - is a general Java Application of some kind (not further defined).
A Java EE Project is a more specified project with predefined libraries - short and really brief described. Java EE is the counterpart to Microsoft's .net. It's used for advanced projects.
regards
Torsten
I never finish anyth...
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java ee refers to the java enterprise edition, it's a platform for web development.
java usually refers to java standard edition,suitable for develope the basic project like swing, gui.
from china
My QQ: 233357374
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I have this code for to create file in directory.
public class Coba {
public static void main(String[] args)throws IOException {
Writer writer = null;
try{
String text = "apa kabar";
File f = new File("d:/azhar.txt");
writer = new BufferedWriter(new FileWriter(f));
writer.write(text);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("file has been created in directori");
}
}
i want to ask ? how to when i run code mentioned, file in directory open automatically..anyone to help me please ??
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I am note sure what exactly your asking, but having a guess;
The file is automatically opened by the FileWriter providing it is not already opened or cannot be created;
This is as per the specification in the java doc; FileWriter[^]
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I mean..file is already create when i run this program,but these file not opened just created in directory. and i wanna when i run this program these file already created and opened automatical also (together).. ??
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please make small sentences and try to explain again what you want to achieve. No one can understand this.
regards
Torsten
I never finish anyth...
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What about this?..
Runtime.getRuntime().exec ("d:/azhar.txt");
This will do for now
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musefan wrote: Runtime.getRuntime().exec ("d:/azhar.txt");
Iam confused where row I put this code ?
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that's just a command forcing the OS to create the txt-file.
stick with your version and try to develop it further on.
regards
Torsten
I never finish anyth...
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Hi to everyone,
I have three classes: Server, ThreadHandler and Client...so far I am able to connect two clients (tried only two so far as that is all i need) to the server and if i type a message in the text field am able to see the "OUTGOING msg" displayed on the text Area...but No "INCOMING msg"...and I've tried searching and couldn't find a solution please note this is for my project and I am asking for a help with solving this problem and here are the codes for each class:
----------------------------------------------------------------
Server Class = LanChatGUI.java (I left out the generated code and the imports)
public class LanChatGUI extends javax.swing.JFrame{
public static ServerSocket serverSocket = null;
public static boolean listen = true;
public LanChatGUI() {
initComponents();
}
public static void main(String args[]) throws IOException {
new LanChatGUI().setVisible(true);
try{
serverSocket = new ServerSocket(7777);
errorLabel.setText(" Waiting connection on port 7777");
}catch(IOException ex){
errorLabel.setText("Listening on port 7777 failed!");
System.exit(-1);
}
while(listen){
new ThreadHandler(serverSocket.accept()).start();
errorLabel.setText(" LocalMessenger client connected on: "
+ serverSocket.getInetAddress() + serverSocket.getLocalPort());
}
}
private javax.swing.JPanel backPanel;
private javax.swing.JLabel bottomLabel;
public static javax.swing.JButton connectButton;
public static javax.swing.JLabel errorLabel;
private javax.swing.JLabel hostlable;
public static javax.swing.JTextField hosttxt;
private javax.swing.JLabel portlabel;
public static javax.swing.JTextField porttxt;
public static javax.swing.JComboBox selectionBox;
private javax.swing.JLabel titleLabel;
ThreadHandler.java
public class ThreadHandler extends Thread {
private Socket connectionSocket = null;
public ThreadHandler(Socket connectionSocket) {
super("ThreadHandler");
this.connectionSocket = connectionSocket;
}
@Override
public void run() {
String to;
BufferedReader userInput = null;
PrintWriter userOutput = null;
try {
userInput = new BufferedReader(new InputStreamReader(
connectionSocket.getInputStream()));
userOutput = new PrintWriter(connectionSocket.getOutputStream(), true);
while((to = userInput.readLine()) != null){
userOutput.print(to);
System.out.println(to);
}
userOutput.close();
userInput.close();
connectionSocket.close();
}catch(IOException e){}
}
}
The bit that I highlighted in bold...I am not sure if tha bit of code is outputting messages sent from a client(A) to a client(B).
--------------------------------------------------------------
Client class --- ChatGUI.java
public class ChatGUI extends javax.swing.JFrame implements Runnable {
public static Socket connectionSocket = null;
public static BufferedReader userInput = null;
public static PrintWriter userOutput = null;
public static StringBuffer toAppend = new StringBuffer("");
public static StringBuffer toSend = new StringBuffer("");
public static String ipAdd = "127.0.0.1";
public static int portNum = 7777;
public ChatGUI() {
initComponents();
convtxtField.addActionListener(new ActionAdapter() {
public void actionPerformed(ActionEvent e) {
String s = convtxtField.getText();
if (!s.equals("")) {
appendToChatBox("OUTGOING: " + s + "\n");
convtxtArea.append(toAppend.toString());
toAppend.setLength(0);
convtxtField.selectAll();
sendString(s);
}
}
});
}
private static void appendToChatBox(String s) {
synchronized (toAppend) {
toAppend.append(s);
}
}
private static void sendString(String s) {
synchronized (toSend) {
toSend.append(s + "\n");
}
}
private static void closeConnection() {
try {
if (connectionSocket != null) {
connectionSocket.close();
connectionSocket = null;
}
}
catch (IOException e) { connectionSocket = null; }
try {
if (userInput != null) {
userInput.close();
userInput = null;
}
}catch (IOException e){userInput = null;}
if (userOutput != null) {
userOutput.close();
userOutput = null;
}
}
public static void main(String args[]) throws IOException {
String s;
new ChatGUI().setVisible(true);
while(true){
try{
connectionSocket = new Socket(ipAdd, portNum);
userInput = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
userOutput = new PrintWriter(connectionSocket.getOutputStream(),true);
}catch(IOException ex){
closeConnection();
}
try{
if (toSend.length() != 0) {
userOutput.print(toSend);
userOutput.flush();
toSend.setLength(0);
}
if (userInput.ready()) {
s = userInput.readLine();
appendToChatBox("INCOMING: " + s + "\n");
convtxtArea.append(toAppend.toString());
toAppend.setLength(0);
}
}catch(IOException ex){
closeConnection();
}
}
}
public static javax.swing.JMenuBar MenuBar;
public static javax.swing.JPopupMenu.Separator MenuSeparator;
public static javax.swing.JMenu aboutMenu;
public static javax.swing.JPanel convPanel;
public static javax.swing.JTextArea convtxtArea;
public static javax.swing.JTextField convtxtField;
public static javax.swing.JMenu exitMenu;
public static javax.swing.JMenu fileMenu;
public static javax.swing.JMenu helpMenu;
public static javax.swing.JMenu logoutMenu;
public static javax.swing.JScrollPane scrollpaneTextArea;
}
class ActionAdapter implements ActionListener {
public void actionPerformed(ActionEvent e) {}
}
So if I run this program the server runs 1st and waits for a client to request a connection and after the client is connected (in this case 2 clients) i type a simple msg like "Hi" from Client A and i type "hello" in Client B i see in the text Area "Outgoing: Hi" in Client A and "Outgoing: Hello" in Client B...but as mentioned above I also want the Incoming messages to be displayed in the text area which i cant figure out how to call the text area in the client class from the ThreadHandler class or mb ther is a different way of doing it so pls help...
P.S. to see if these messages are been sent to the server..in the "ThreadHandler class" i entered "System.out.println(s);" the bit coloured in red and in the console it shows messages from both clients...so as said i guess all i am missing is the "Incoming part from the server side"....I would appreciate if any1 could assist me with this!
All i need is to see incoming messages in both clients other than that everything is working... pls help as i am suppose to submit this by nxt week...
Many thanks
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Please use <pre></pre> tags around your code (not <code>) to ensure correct formatting.
I must get a clever new signature for 2011.
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Hello,
I'm wondering if it's possible to get sound which other apps are playing for example from music or movie player. If it is then how to do this?
Edit: I've probably found a solution, but didn't check if it works. VAC - Virtual Audio Cable. It installs virtual sound card in system so we can play all of our sounds into it and then retrive it through Java Sound API with TargetDataLine. It's platform dependent, but it's always an option. There is also StereoMix available in some sound cards and I think it's worth of notice. On linux it's probably possible to achieve it with JACK.
modified on Saturday, March 12, 2011 7:30 PM
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Hey,
I have an quick question about the keyword new.
Basically I'm not sure what the new word does and would like to know why exaclty why you use it.
The best way I learn is by seeing examples so can someone reply with an example where if new was not present a piece of code would not work
Mucho gracias
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Basically, the keyword new is to initialize a new object. If you need to create an object, you would use the new keyword to initialize the object such as, Car myCar = new Car(). This creates a new Car object which is then assigned the variable name myCar. Here is a link to java's tutorial page to find some more examples and more information about the keyword new.
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To expand on this example and tie in the idea of an "instance" of an object:
CCarClass *myCar = new CCarClass();
CCarClass *sisterCar = new CCarClass();
This would create two specific and individual instances of the class, each its own object, on the heap (as opposed to the stack). They will persist until you delete them (which in C++ you must do yourself to clean up resources).
delete myCar;
delete sisterCar;
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Albert Holguin wrote: They will persist until you delete them (which in C++ you must do
yourself to clean up resources).
In java of course you do not delete them.
They are cleaned by the garbage collector when there are no more active references to them.
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lol... didn't realize this was posted in the java forum... my bad! assumed C++
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