Java Sockets - help with using objects

I am new to java sockets, and need to come up with a way to send a user defined instance of a class across a basic client/server application.
I can not find out how to do this. I read the tutorials, but my class can not be serialized. How can I send/recieve this instance of a user defined class?

right off the top of my head, doesn't serialver just spit out a UID for a given set of classes?
To mark a class as Serializable, just implement the java.io.Serializable class - then you could use the readObject/writeObject methods of the ObjectInputStream/ObjectOutputStream classes.
Good luck
Lee

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I need help with using the Make With Top Object envelope distortion.

I'm doing a project for school called "Ocean Of Stars". I have a few objects,a sheet of purple stars and a few blue gradient colored circles. I need to merge the stars and the circles as one object, but when I click the Make with top object command, the color in the cicles disappear. I don't know what I'm doing wrong.
this is what my screen looks like now.
And this is what I need to make.
Any help is greatly appreciated!
Thanks!

His spheres are 3d yours are 2d. See what happens when you revolve a 1/2 a sphere. You will find a way to apply the stars in that same dialog box if you look really hard.

Help with Classes, Objects and their relationship.

Alright, I've got this assignment from a computer science class that won't stop annoying me and I need some help. This is the complete assignment: http://zebra0.com/Tarraga/CS103/Project4.php
What I'm having issues with is the course specifications. It says:
? Create a course class. It will contain the course name, 5 Student objects, the number of Students, etc. It will contain an addStudent(), printRoll() and average() methods. You may add methods as needed. The average method computes the average of all students test score averages.
I'm not sure what my instructor means by 5 student objects. I'm assuming that addStudent() would create a new student() object (from the class which I've already created here: http://zebra0.com/Tarraga/CS103/studentP4.php) and printRoll() will print the existing objects, average() I think I know.
So...wth am I supposed to create 5 student objects for? Or what are they referring to? I'd assume that the student objects are created only when the user inputs the student data, not internally.
My question is what I'm assuming to be extremely newb-ish, and to be honest I am a complete newbie, but if anyone can help please do so.
Edit: Another question I had regarded my student class would be, do I need to write getters/setters for every value in there? My instructor wouldn't stop raving about how we need getters/setters, but at this point I'm not exactly sure what they do.

to didittoday:
You could say that, yes. But honestly...I've been paying plenty of attention. What I've learned so far about an object in Java is the following:
An object in programming is like an object in real life. It makes up the program. Just like a wheel is part(object) of a card, an object is part of the program.
That's what my teacher has taught me, with pictures even. I've written about two GUI and one non GUI projects so far that I had to look to the book to actually finish. And that's her general answer to all our questions, "read the book!" She doesn't ever take time from showing us her precious powerpoints to actually teach us. And not once has she actually given us examples of coding. She instead directs us to the programs in our book which may or may not be of relevance.
And all the tutors who could actually help me aren't on campus. If you'd like to redirect me to a link that may hold useful (and RELEVANT) information, please do so.
Also: I do understand that a student object would hold student information (I.E.:
public student (String firstname, String lastname, double score1, double score2, double score3, double score4)but I don't understand why 5 student objects should be created in the other class...is it that they have to be initialized and then once the user inputs the information, they are updated? I'm grasping at straws here.
Edited by: Valkyrio on Mar 5, 2008 3:28 PM

Help with using multiple hard drives

Is there a way to install the OS on an "external" (expresscard SSD) drive, but have all of the library and data files on the primary hard disk? I LOVE the speed on my SSD, but it's a pain finding stuff now. Is this something a RAID configuration could help with?

mwmmartin wrote:
I have a 1 TB hard drive; but I have a 500GB and 250GB usb external hard drives.
Wouldn't it be cool if I could make the two external hard drives a RAID drive and use Time Machine to use all the 750GB of external memory to do my backups???
You can, but I would +*strongly recommend against+* it. See +Concatenated RAID+ in the Help for Disk Utility.
There are several potential problems:
Depending on how much data is on your 1 TB drive, 750 GB may not be enough to back it up. See #1 in Time Machine - Frequently Asked Questions (or use the link in *User Tips* at the top of this forum).
To set up a +Concatenated RAID+ set, both drives will be erased.
When (not if) either drive fails, you'll lose all the data on both.
Both drives must be connected any time you do a backup or want to browse your backups.
Especially with USB, if one drive wakes from sleep, or spins up, quickly enough, but the other one doesn't, the backup may fail and/or your backups may be corrupted.
For now, it looks like my only solution is to go buy a bigger external hard drive and spend more money,,,
That's your best solution +*by far.+* Anything else is taking a large risk with your backups.

Help with layered objects

I am new to Pages and struggling to layer objects. I am working with opacity, but unable to move one object on top of another.
thanks for any help,
Kim

Welcome to Apple Discussions Kim
When you insert any object in a Pages document & have it "fixed on page," by default wrap is turned on with a 12 point gutter. This results in objects "pushing" other objects out of the way. With your object(s) selected, go to the wrap inspector & uncheck "object causes wrap." Unfortunately, there is no way to change this default setting, it will have to be done manually for any object inserted. You may wish to leave feedback for the Pages team asking that the ability to have wrap apply to all objects or not be added as a preference in future versions of Pages.

Need help with using Solaris FLAR across disparate platforms

All,
I need help with what needs to be done to use solaris Flash for disaster recovery between the disparate Server platforms listed below.
I am concerned about the platform specific files that would be missing?
Note: All our servers are installed with the SUNWCprog cluster through Custom jumpstart and We use disksuite for mirroring the operating system drives.
Primary Server     Recovery Server
Sun Fire 6800     Sun Fire E2900
Sun Fire E2900     Sun Fire 6800
Sun Fire-880     Sun Fire-V440
Sun Fire-V440     Sun Fire-880
Sun Fire 4800     Sun Fire-880
Sun Fire-V890     Sun Fire 4800
Me

jds2n,
Is it possible to get around installing the Entire Distribution + OEM and include only the platform specific files?
Just a thought
Example:
I would like to create a Flash Archive of a E2900 server which i plan to use to recover a 6900.
The 2900 was installed with a developer cluster.
When creating the Flash archive of the 2900 is it possible to add the 6900 platform specific files and drivers
from the Solaris CD?
Thanks

Need help with using Email Activation Agent

Hi,
please, help me with using E-mail Activation Agent.
I used email activation agent to start business processes by email, but after that letter disappear from email-server.
Where letter was located?
Can I get and read letter for processing?

Mail/Preferences/General - do you have Unibox set as your default e-mail application?

Help with using a web page from disk after saved from web

Hi, I almost forgot the little I learned about web page development, so, I'm a total noob when it comes to this and I need your help.
I saved as a complete web page on my hard disk this web page but when I open it in Firefox or IE, it doesn't display as much as I need it. I'm mostly interested in displaying the logo images as they appear on the original web page. The browsers just show them briefly when refreshing but hide them right away. I can see the image files downloaded to my hard drive and if I open the page in Dreamweaver it displays these images in the preview pane but I can't make them show in the browsers. From Dreamweaver I saved the page as in the folder where the images are and this also updated the code with the relative image links but the browsers still don't show them.
I will greatly appreciate your help with this.

I'm sorry, but your post is very confusing
I saved as a complete web page on my hard disk this web page
Does this include site definitions?
when I open it in Firefox or IE, it doesn't display as much as I need it.
I dont know what this means...are there images that are not being displayed? Is there styling that is not being rendered?
. I'm mostly interested in displaying the logo images as they appear on the original web page. The browsers just show them briefly when refreshing but hide them right away.
Again, I dont know what this means?
I can see the image files downloaded to my hard drive and if I open the page in Dreamweaver it displays these images in the preview pane but I can't make them show in the browsers. From Dreamweaver I saved the page as in the folder where the images are and this also updated the code with the relative image links but the browsers still don't show them.I will greatly appreciate your help with this.
Do you have a link to the page, and perhaps some explanation that is more clear as to what your issue is.
Gary

I need help with File Object in Java

Hello Experts.
I am learning Java 2 now. I have trouble with reading a JTextField and save it to a file. I have some errors that I dont know what they are. I would like someone please help me to write a short sample program to see how it work. The code from the book I have dont execute at all. And I want to use FileOutputStream and ObjectOutputStream. Thank you very much
Quoc

import java.io.*;
public class FileTest {
public static void main(String[] arg) throws Exception{
    FileOutputStream fileOut = new FileOutputStream("test.txt");
    fileOut.write("Test file".getBytes());
    fileOut.close();

HELP!!! Need help with using DOS comds from Java

I am trying to run ftp in DOS by using the following code, only its not working, when I run the program it opens the DOS window but nothing happens, it does run but returns me two the command prompt straight away. If anyone can help it would be great, thanks in advance.
import java.io.*;
class DosCmd{
public static void main(String [] args){
try{
Runtime rt = Runtime.getRuntime();
Process child = rt.exec("start ftp /c ftp 172.20.2.134");
child.waitFor();
catch(IOException io){}
catch(InterruptedException e) {}

I agree with ChuckBing,
there is no option /c for ftp as far as I know (http://www.microsoft.com/windows2000/en/server/help/ftp.htm), why don't you try "start ftp 172.20.2.134"? What should this "/c" option do?
Hope this helps,
FReAK

Help with use of Java Stored Procedures to invoke Java Code within Applicat

Good afternoon everyone
Our development team is looking for some assistance/validation of a design strategy we are deploying for a client. Let me first layout the environment and then the design issue at hand:
Business User Workstation component: Oracle SQL*Developer 1.5.x
Reporting Tool: Actuate e.Spreadsheet A10
Application Web UI: J2EE application developed with Eclipse
Application Scripting: Application has a scripting component whereby business users can write Oracle PL/SQL to perform many of the functions that are available in the Web UI, but can be batched up or repeated several times.
Application Server WebLogic 9.2.3 (client constraint)
Database Serve: Oracle 11g, Release 11.1.0.7
Lots of other stuff included but irrelevant for this conversation.
Here's the scenario in question:
1.     Through the scripting solution, the application user must use PL/SQL to invoke functionality within the Web UI. All PL/SQL that the application user creates does not contain any SQL. Instead our security model mandates that “pre-defined” routines will perform all of the SQL operations against the database; the application user simply invokes the stored procedures of functions to perform activities in the database.
2.     There is a component of the scripting application that facilitates the creation of reports. In our application, we are using Actuate’s e.Spreadsheet Engine to create the report and format the report based on a template. The template is provided as input, as well as other data items, into Actuate for processing. The net result is the report is created by the Actuate e.Spreadsheet engine in pdf format and then sent back to the user for distribution to other users in the company.
3.     The Actuate e.Spreadsheet engine consists of one or more JAR files within the Application Server framework. The Web UI utilizes these JAR files as well to perform report generation and data manipulation activities. In the case of the reporting functionality, the pdf report that is generated by Actuate is returned into either the Web UI or into the scripting component for persistence in the database. The mechanism exists to create multi-step jobs that can create multiple reports in one run.
4.     So to facilitate the above, we are creating one or more Java Stored Procedures that will mediate the communication between the PL/SQL the user’s create and the Java components that are required for business processing. PL/SQL will invoke one or more Java Stored Procedures. Then the Java Stored Procedures invoke Actuate e.Spreadsheet, generate the report, saves the report in the database and returns control back to the invoking procedure.
So the question is: Is this a viable and correct use of Oracle Java Stored Procedures. What are the advantages/disadvantages of doing so? Any security issues or potholes that you can think of? Tuning issues for the JVMs? Any white papers that you can think of?
For any Oracle employees that respond, material such as Oracle Whitepapers, etc. would be great.
I can be contacted at (313) 227-4350 or at [email protected]
Thanks in advance.

So are you planning on loading the entire e.Spreadsheet engine into the database server's JVM?
If so, I would expect that to work, but I expect that you'd have some performance issues. I'd expect that the process of building these PDFs is going to be relatively expensive. Tuning the database server's JVM tends to be rather more challenging than tuning JVM's in an app server.
If not, I'm not sure how the Java stored procedure would invoke the e.Spreadsheet engine on the application server. It is possible to use Oracle AQ to send a JMS message, but I don't think you can use the standard J2EE JMS APIs-- I think you'd have to use Oracle's AQ interface.
Justin

Help with using Scanner Class

Hi there - I'm a newbie to Java and may have posted this in the wrong forum previously.
I am trying to modify a program so instead of using a BufferReader, a scanner class will be used. It is basically a program to read in a name and then display the variable in a line of text.
Being new to Java and a weak programmer, I am getting in a mess with this and missing something somewhere. I don't think I'm using scanner in the correct way.
Any help or pointers would be good. There are 2 programs of code being used. 'Sample' and 'Run Sample'
Thanks in advance.
Firstly, this program will run named 'Sample'
<code>
* Sample.java
* Class description and usage here.
* Created on 15 October 2006
package internetics;
* @author John
* @version 1.2
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
// import com.ralph.*;
public class Sample extends JFrame
implements java.awt.event.ActionListener{
private JButton jButton1; // this button is for pressing
private JLabel jLabel1;
private String name;
/** Creates new object ChooseFile */
public Sample() {
initComponents();
name = "";
selectInput();
public Sample(String name) {
this();
this.name = name;
private void initComponents() {
Color bright = Color.red;
jButton1 = new JButton();
jLabel1= new JLabel();
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent evt) {
exitForm(evt);
getContentPane().setLayout(new java.awt.GridLayout(2, 1));
jButton1.setBackground(Color.white);
jButton1.setFont(new Font("Verdana", 1, 12));
jButton1.setForeground(bright);
jButton1.setText("Click Me!");
jButton1.addActionListener(this);
jLabel1.setFont(new Font("Verdana", 1, 18));
jLabel1.setText("05975575");
jLabel1.setOpaque(true);
getContentPane().add(jButton1);
getContentPane().add(jLabel1);
pack();
public void actionPerformed(ActionEvent evt) {
System.out.print("Talk to me " name " : ");
try {
jLabel1.setText(input.readLine());
} catch (IOException ioe) {
jLabel1.setText("Ow! You pushed my button");
System.err.println("IO Error: " + ioe);
/** Exit this Application */
private void exitForm(WindowEvent evt) {
System.exit(0);
/** Initialise and Scan input Stream */
private void selectInput() {
input = new Scanner(new InputStreamReader(System.in));
/**int i = sc.nextInt(); */
/** Getter for name prompt */
public String getName() {
return name;
/** Setter for name prompt */
public void setName(String name) {
this.name = name;
* @param args the command line arguments
public static void main(String args[]) {
new Sample("John").show();
</code>
and this is the second program called 'RunSample will run.
<code>
class RunSample {
public static void main(String args[]) {
new internetics.Sample("John").show();
</code>

The compiler I'm using is showing errors in these areas of the code. I've read the tutorials and still can't get it. They syntax for the scanner must be in the wrong format??
the input.readLine appears incorrect below.
public void actionPerformed(ActionEvent evt) {
    System.out.print("Talk to me " +name+ " : ");
    try {
        jLabel1.setText(input.readLine());
    } catch (IOException ioe) {
      jLabel1.setText("Ow! You pushed my button");
      System.err.println("IO Error: " + ioe);
    }and also here...
the input is showing errors
/** Initialise and Scan input Stream */
private void selectInput() {
    input = new Scanner(new InputStreamReader(System.in));
   /**int i = sc.nextInt(); */
}Thanks

I need help with a Object Array

I am having trouble and this maybe really simple seeing that I am fairly new to java but I have text that is being broken down in to preset part with those parts stored in Object arrays.
Now I also have a object array inside my object array. Within the second object array are the broken down parts of the text and I want to compare this text with another string so for example this is what I am trying
boolean found = false;
for (int i = 0; i < FirstObjectArray.length ;i++)
     Object[] SecondObjectArray = (Object[]) FirstObjectArray;
     if(SecondObjectArray[0] == "string")
          found = true;
          break;
     else
          found = false;
}Help would be very appreciated.

astlanda wrote:
Sure, you're right.
[public boolean equals(Object obj)|http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Object.html#equals%28java.lang.Object%29]
sharkura said all the OP needs at the moment. I just wanted to clarify a bit why You don't use == 99.999% of the time with objects, and never with String.
I have argued elsewhere in these forums that it is inappropriate to tell anyone that you never use == to compare objects. This has not always been accepted. I have, on rare occasions, known experienced developers to blindly compare two objects with equals(), and cite the professor that taught them, 15 years iin the past, that object references are never compared using ==, but always with equals().
However, the cases where == is appropriate and equals() is not are indeed rare, but not, in my experience, non-existent. In my statement, I probably exaggerated. And String is a case where I can probably accept that you will probably never go wrong with equals(). If the String has been pooled (see String::intern()), you can actually use either. From the javadocs: "*It follows that for any two strings s and t, s.intern() == t.intern() is true if and only if s.equals(t) is true.*"
¦ {Þ

Help with string object code

Hello,
First off thanks in advance to anyone who helps. I am trying to write a program that using a class string object to convert this kind of "text speech" to english. For example if the user inputs "HowAreYou?", I want the program to output "How are you?" I am having too much trouble with strings for some reason. This is what I have so far and I am not sure where to go from here. Should I use a do loop to check through the input string until it is done seperating the words? And how should I go about doing that?
import java.util.Scanner;
public class P8
public static void main( String args[] )
char choice;
String line = null;
String answer = null;
Scanner scan = new Scanner(System.in);
do
System.out.println();
System.out.print("ENTER TextSpeak sentence(s): ");
line = scan.nextLine();
System.out.print( "Converted to English: \t ");
System.out.print( textSpeaktoEng( line ) );
System.out.println();
System.out.print("Want more TextSpeak?\t\t ");
answer = scan.next();
choice = answer.charAt(0);
if( scan.hasNextLine() )
answer = scan.nextLine();
}while(choice != 'N' && choice != 'n');
public static String textSpeakToEng(String s)
String engStr = null;
if( Character.isUpperCase( s.charAt(j) ) )
engStr += ? ?;
engStr += Character.toLowerCase( s.charAt(j) );
scan.close();
}

I got my program to compile and run but I have a problem. If I input something like "ThisForumIsGreat" it will output just "t f i g" in lower case letters. Any suggestions?
import java.util.Scanner;
public class P8
public static void main( String args[] )
   char     choice;                          // Repeat until n or N
   String line   = null;                     // Sentences to toTextSpeak
   String answer = null;                     // Repeat program scan
   Scanner scan = new Scanner(System.in);    // Read from keyboard
   do
      System.out.println();
      System.out.print("ENTER TextSpeak sentence(s): ");
      line = scan.nextLine();                // Read input line
      System.out.print( "Converted to English: \t    ");
      System.out.print( textSpeakToEng( line ) );
      System.out.println();
      System.out.print("Want more TextSpeak?\t\t ");
      answer = scan.next();                  // Read line, assign to string
      choice = answer.charAt(0);             // Assign 1st character
      if( scan.hasNextLine() )               // <ENTER> character
        answer = scan.nextLine();            // Read line, discard
}while(choice != 'N' && choice != 'n');    // Repeat until input start n or N
public static String textSpeakToEng(String s)
   String engStr = null;
   int i;
   for ( i = 0; i < s.length(); ++i )
   if( Character.isUpperCase( s.charAt(i) ) )
     engStr += " ";                                  // Append 1 blank space
     engStr += Character.toLowerCase( s.charAt(i) ); // Append lowercase
   return( engStr );
}

Need help with Calling objects

I have created an object named "user" and I currently have 1 Frame in my program. The first frame is called "LogonFrame" and the second is called "UserDataFrame".
In the main method of the application I declare a "User" object as user and then call LogonFrame to retreive the logon_name and password from the user. The logon_name and password will be placed in the User object to be accessed throughout the application.
When I compile the application I receive the following error message:
Error: (85) variable user not found in class GL2.LogonFrame
*I know that 85 is the line number that the error is located
*GL2 is the name of the package.
Has anyone ever encountered this error before, and if so how can I fix this error.
*Listed below is the code used in the User object if it helps at all.
Jason Franz
// Copyright (c) 2003 Jason T. Franz
package GL2;
* A Class class.
* <P>
* @author Jason T. Franz
public class User extends Object {
private static int user_id;
private static String first_name;
private static String last_name;
public static void User(){
user_id = 0;
first_name = "";
last_name = "";
//sets the user ID
public static void setUserID(int newID){
user_id = newID;
//Returns the User ID
public static int getUserID(){
return user_id;
//Sets the User First Name
public static void setFirstName(String newFirstName){
first_name = newFirstName;
//Gets the Users First Name
public static String getFirstName(){
return first_name;
//Sets the Users Last Name
public static void setLastName(String newLastName){
last_name = newLastName;
public static String getLastName(){
return last_name;
//Resets all data in the User Class
public static void reset(){
user_id = 0;
first_name = "";
last_name = "";

The code below is a small portion of the program.
If it helps at all I am useing Oracle JDeveloper version 3.2.3 with JDK1.2.2_JDeveloper
This section is the User object
// Copyright (c) 2003 Jason T. Franz
package GL2;
* A Class class.
* <P>
* @author Jason T. Franz
public class User extends Object {
private String first_name;
private String last_name;
public User(){
    first_name = "Jason";
    last_name = "Franz";
//Sets the User First Name
public void setFirstName(String newFirstName){
    first_name = newFirstName;
//Gets the Users First Name
public String getFirstName(){
    return first_name;
//Sets the Users Last Name
public void setLastName(String newLastName){
    last_name = newLastName;
public String getLastName(){
    return last_name;
//Resets all data in the User Class
public void reset(){
    first_name = "";
    last_name = "";
    logon_name = "";
    user_password = "";
}Here is the main method.
// Copyright (c) 2003 Jason T. Franz
package GL2;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
* GL2.DevilsHead
* <P>
* @author Jason T. Franz
public class DevilsHead {
public User user = new User();
   * Constructor
public DevilsHead() {
    AddUserFrame frame = new AddUserFrame();
    //Center the window
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension frameSize = frame.getSize();
    if (frameSize.height > screenSize.height) {
      frameSize.height = screenSize.height;
    if (frameSize.width > screenSize.width) {
      frameSize.width = screenSize.width;
    frame.setLocation((screenSize.width - frameSize.width)/2, (screenSize.height - frameSize.height)/2);
    frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } });
    frame.setVisible(true);
   * main
   * @param args
public static void main(String[] args) {
    try {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    catch (Exception e) {
      e.printStackTrace();
    new DevilsHead();
}and here is the Frame which calls the user object to display the Information.
// Copyright (c) 2003 Jason T. Franz
package GL2;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
* A Swing-based top level window class.
* <P>
* @author Jason T. Franz
public class AddUserFrame extends JFrame {
BorderLayout borderLayout1 = new BorderLayout();
JPanel jPanel1 = new JPanel();
Button button1 = new Button();
   * Constructs a new instance.
public AddUserFrame() {
    super();
    try {
      jbInit();
    catch (Exception e) {
      e.printStackTrace();
   * Initializes the state of this instance.
private void jbInit() throws Exception {
    this.getContentPane().setLayout(borderLayout1);
    this.setSize(new Dimension(400, 300));
    button1.setLabel("button1");
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button1_actionPerformed(e);
    this.setTitle("Add a User");
    this.getContentPane().add(jPanel1, BorderLayout.CENTER);
    jPanel1.add(button1, null);
void button1_actionPerformed(ActionEvent e) {
    System.out.println(user.getFirstName());
    System.out.println(user.getLastName());
}The error I receive is
Error: (51) variable user not found in class GL2.AddUserFrame

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