Help with Threads in java...

Hi all,
the problem it's the following:
i got a program that update a sql server table. So i want, at the same time, run this program many times, say 10 for example, to do it that faster.
But i only want 10 subprograms at the same time. So i got to use wait() and others method's, rigth?
I'm not shure about this, because a never use threads.
So any help, code or "pseudocode" will be very appreciated.
Thanks in advance
A. Santos

Hi santhos,
If u use 10 threads to read the sql table, then
ur program will lose the sequence. If u have a idea
to split the program then u can use threads.
Regards,
Palaniyappan

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I need help with threads. How can I break this code into teo threads without chaning the data objects at all? Producer will produce string line by line and consumer will take the line and search for the word. Help me please.
Thank you
public class WordFinder
* Main program opens the file given by the user as an argument and
* searches for the word given by the user. If the word is found,
* the line number on which the word occurs is displayed.
* @param args[0] Word to search for
* @param args[1] Name of file to search
public static void main(String[] args) throws IOException
// To keep track of how long the program runs we'll set the startTime
// variable to the current time in milliseconds and use that at
// the end of the program to find out how long we ran.
long startTime = System.currentTimeMillis();
String wordToFind;
String currentLine;
int lineCount = 0; // Keep track of line numbers
BufferedReader inputFile = null; // Needed to get compiler to quit
// complaining about uninitialized
// variables.
// Make sure we have 2 arguments passed to us
if (args.length < 2)
// Nope. Show user how to run and then exit with an error (1)
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// Set the wordToFind variable to refer to args[0]. We don't
// really need to do this, but it makes our code more readable
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// We're going to read the file one line at a time. For each
// line, we'll create a StringTokenizer object to break the line
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You may create Queue object. (I guess that you're already know QUEUE)
Then ... use producer thread to load input file into queue. (Enqueue)
Consumer ... dequeue
Queue can be empty because of
- Input file was read to EOF and Consumer had produced all queue.
or
- Cunsumer works too fast... So the queue is empty.
So, you may have to use ... wait() in Consumer in case of the queue is empty.
And use notify() in Producer to wake up consumer ...
Is this right ?

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We have problems with our application which runs on bea8.1 sp1.
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thread dums look same for all threads but i can's see what is wrong.
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at com.hutchison3g.core.product.homebase.client.HomebaseClient.getIdentity(HomebaseClient.java:207)
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at com.hutchison3g.core.product.homebase.client.servlet.core.HomebaseCommonServlet.service(HomebaseCommonServlet.
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at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
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at java.io.BufferedInputStream.fill(BufferedInputStream.java:183)
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at java.io.DataInputStream.readByte(DataInputStream.java:276)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:189)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:133)
at com.hutchison3g.core.product.homebase.services.HomebaseFactoryImpl_Stub.getIdentity(Unknown
Source)
at com.hutchison3g.core.product.homebase.client.HomebaseClient.getIdentity(HomebaseClient.java:207)
at com.hutchison3g.core.product.homebase.client.util.HomebaseProxy.getIdentity(HomebaseProxy.java:78)
at com.hutchison3g.core.product.homebase.client.util.UserUtil.getIdentity(UserUtil.java:132)
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at com.hutchison3g.core.product.homebase.client.servlet.core.HomebaseCommonServlet.service(HomebaseCommonServlet.
java:72)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6310)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
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Rob Woollen <[email protected]> wrote:
Can you post the full thread dump?
It looks like you have some code making an RMI call over the network.
Is it calling another server, or perhaps a loopback call into the same
server. The latter (opening a socket to your own process) is a good
way
to get a deadlock.
-- Rob
dara wrote:
We have problems with our application which runs on bea8.1 sp1.
Problem is that bea runs out from Threads (StuckThreads).
thread dums look same for all threads but i can's see what is wrong.
Here are dumps from first and last threads :
"ExecuteThread: '1' for queue: 'weblogic.kernel.Default'" daemon prio=5tid=0x7f3628
nid=0xd runnable [a6280000..a6281994
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:183)
at java.io.BufferedInputStream.read(BufferedInputStream.java:201)
- locked <c3197aa0> (a java.io.BufferedInputStream)
at java.io.DataInputStream.readByte(DataInputStream.java:276)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:189)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:133)
at com.hutchison3g.core.product.homebase.services.HomebaseFactoryImpl_Stub.getIdentity(Unknown
Source)
at com.hutchison3g.core.product.homebase.client.HomebaseClient.getIdentity(HomebaseClient.java:207)
at com.hutchison3g.core.product.homebase.client.util.HomebaseProxy.getIdentity(HomebaseProxy.java:78)
at com.hutchison3g.core.product.homebase.client.util.UserUtil.getIdentity(UserUtil.java:132)
at com.hutchison3g.core.product.homebase.servlets.TalonUniServlet.doGet(TalonUniServlet.java:181)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at com.hutchison3g.core.product.homebase.client.servlet.core.HomebaseCommonServlet.service(HomebaseCommonServlet.
java:72)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6310)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
"ExecuteThread: '24' for queue: 'weblogic.kernel.Default'" daemon prio=5tid=0x6dd548
nid=0x24 runnable [a3d80000..a3d819
94]
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:183)
at java.io.BufferedInputStream.read(BufferedInputStream.java:201)
- locked <c30c5010> (a java.io.BufferedInputStream)
at java.io.DataInputStream.readByte(DataInputStream.java:276)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:189)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:133)
at com.hutchison3g.core.product.homebase.services.HomebaseFactoryImpl_Stub.getIdentity(Unknown
Source)
at com.hutchison3g.core.product.homebase.client.HomebaseClient.getIdentity(HomebaseClient.java:207)
at com.hutchison3g.core.product.homebase.client.util.HomebaseProxy.getIdentity(HomebaseProxy.java:78)
at com.hutchison3g.core.product.homebase.client.util.UserUtil.getIdentity(UserUtil.java:132)
at com.hutchison3g.core.product.homebase.servlets.TalonUniServlet.doGet(TalonUniServlet.java:181)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at com.hutchison3g.core.product.homebase.client.servlet.core.HomebaseCommonServlet.service(HomebaseCommonServlet.
java:72)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6310)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
Thanks Rob,
sorry for delay but I was on vacation.
You are right about RMI, our app. consist from FE (front end) and BE (back end),
comunication between them is RMI.
We had some problems with BE but now we have new version and it looks ok.
Anyway thanks for help, if I will have again some problems then it will be
Help with thread analisys 2 ;-)

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import java.sql.*;
import...
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Edited by: RobertHix on Oct 6, 2009 3:54 AM

Thanks for the help, but that did not work. I tried flushing the ObjectOutputStream and it is still hanging when initializing the thread.
Here is a better look at the code since I was helped to figure out how to insert it:
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package playingwiththreads1;
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public class ReceiverThread implements Runnable {
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        catch (IOException e)
            System.out.println(e);
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        for (int i = 0; i < 51; i++) (new Thread(new bot(i))).start();
}I'm trying to run 50 threads, each doing their task of downloading data, parsing it and inserting where applicable into the MySQL database. 50 should reduce difference in last and latest crawled to 1 hour, which would be great!
Am I missing something? Is there anything special that needs to be taken into consideration when using MySQL?
Any help much appreciated!

Wow, that's a bummer :-(
I managed to get this working, showing 50 simultaneous connections to MySQL, but the connections appear to be "sleeping" most of the time which leads me to believe it's the problem you're suggesting.
Thanks for the heads up, could save me a lot of headaches!

Help with a SIMPLE java thing

I've only got ONE handful of hair left.
I'm trying to build a series of dropdown boxes; a day dropdown (Mon, Tue, Wed...), a month dropdown (Jan, Feb, Mar...), a year dropdown, hour dropdown, minute dropdown, and an am/pm dropdown.
I think I want to build my dropdowns using "for" loops something like this:
for (i=0;i<12;i++) {
myStringBuffer.append("<option>" + [someUnknownFunctionThatReturnsTheFirstThreeLettersOfTheMonth(i)] + "</option>")
I've been trying to mix up various combinations of Date objects (most date functions seem to be depreciated), Calendar Objects, DateFormat Objects and SimpleDateFormat Objects but nothing seems to want to perform the function that I need.
I've had iffy success creating a calendar object, setting the Month to "i", using the getTime function to return a Date object which I can then pass to the SimpleDateFormat object using the .format(Date) function, after setting the pattern to "EEE", but it seems like just an incredibly complicated way to do what ought to be a simple function...i.e. convert a number 0-11 (or 1-12, I'm not picky) into the name of a stinking Month! Arrgh.
If anyone can help, I thank you.

I've done that before, so i'll share it with you.
import java.text.SimpleDateFormat;
import java.text.DateFormatSymbols;
import java.util.Calendar;
import java.util.Date;
public String createListOfMonth(String pName) {
StringBuffer sbMonth = new StringBuffer();
DateFormatSymbols fm = new DateFormatSymbols();
String[] arrMonth = fm.getMonths();
sbMonth.append("<select name=\"" + pName + "\">");
sbMonth.append("     <option value=\"\">Month</option>\n");
for (int i=0; i<arrMonth.length; i++) {
if (!arrMonth.trim().equals("")) {
String sValue = "0000" + (i + 1);
sValue = sValue.substring(sValue.length() - 2);
sbMonth.append("     <option value=\"" + sValue + "\">" + arrMonth[i] + "</option>\n");
sbMonth.append("</select>");
return (sbMonth.toString());
You can manipulate the symbol (either for months, days) using different locale. You can see the API for java.text.DateFormatSymbols in Java2 SE.
Regards,
Hariyanto

Im DROWNING! need help with a simple java assignment! plz someone help me!

i need help with my java assignment, with validating a sin number. easy for must who know java. im drowning... please help!

You will need to store each digit of the social insurance number in a field of its own. To validate the entry you will:
1. Multiply the 2nd, 4th, 6th and 8th digit by 2.
2. If the product of any of the four multiplications result in a value greater than 9, add the two resulting digits together to yield a single-digit response. For example 6 * 2 = 12, so you would add the 1 and the 2 to get a result of 3.
3. Add these four calculated values together, along with the 1st, 3rd, 5th, and 7th digits of the original number.
4. Subtract this sum from the next highest multiple of 10.
5. The difference should be equal to the 9th digit, which is considered the check digit.
Example of validating S.I.N. 765932546
1st digit 7
2nd digit (6*2 =12 1+2=) 3
3rd digit 5
4th digit (9*2 = 18 1+8 =) 9
5th digit 3
6th digit (2*2 = 4) 4
7th digit 5
8th digit (4*2 = 8) 8
Total 44 next multiple of 10 is 50
50-44 = 6 which is the 9th digit
Therefore the S.I.N. 765932546 is Valid
********* SIN Validation *********
Welcome - Please enter the first number: 120406780
Second digit value multiplied by 2 4
Fourth digit value multiplied by 2 8
Sixth digit value multiplied by 2 12
Eighth digit value multiplied by 2 16
Value derived from 6th digit 3
Value derived from 8th digit 7
The total is 30
Calculated digit is 10
Check digit must be zero because calculated value is 10
The SIN 120406780 is Valid
this is my assignemtn this is what i have! i dont know where to start! please help me!
/*     File:     sinnumber.java
     Author:     Ashley
     Date:     October 2006
     Purpose: Lab1
import java.util.Scanner;
public class Lab1
          public static void main(String[] args)
               Scanner input = new Scanner(System.in);
               int sin = 0;
               int number0, number1, number2, number3, number4, number5, number6, number7, number8;
               int count = 0;
               int second, fourth, sixth, eighth;
               System.out.print("\t\n**********************************");
               System.out.print("\t\n**********SIN Validation**********");
               System.out.print("\t\n**********************************");
               System.out.println("\t\nPlease enter the First sin number: ");
               sin = input.nextInt();
               count = int.length(sin);
               if (count > 8 || count < 8)
               System.out.print("Valid: ");
     }

Wanted: Help with thread in spanish; guitar not recording

Can someone please help with this thread?
GarangeBand No Reconoce Mi Guitarra Audio
The op has trouble to connect his guitar. I cannot interview him in spanish, and he does not know to ask in English.
Appriciate any help.
Léonie

Hi Borris12,
I'll clear this up for you and let you know whats happened.
Could you drop me in an email please with your BT account and telephone number along with a link back to this thread.
Just send to the email address in my profile and mark FAO Craig please.
Thx
Craig
BTCare Community Mod
If we have asked you to email us with your details, please make sure you are logged in to the forum, otherwise you will not be able to see our ‘Contact Us’ link within our profiles.
We are sorry but we are unable to deal with service/account queries via the private message(PM) function so please don't PM your account info, we need to deal with this via our email account :-)”
td-p/30">Ratings star on the left-hand side of the post.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.

Need help with long term Java problems

I've been having problems with Java on my computer for about a year now, and I'm hoping that someone here can help me out.
Java used to work fine on the computer when I first got it (a Dell laptop) and I hadn't installed anything myself. But then one day it stopped loading Java applets, and hasn't worked since. By this, I mean that I get the little colorful symbol in a box when I try to play Yahoo games, use the http://www.jigzone.com site, go to chat rooms, etc. Java menus on websites like http://www.hartattack.tv used to work still, but lately they've been giving me that symbol too.
I've tried downloading a newer version of Java, but nothing I do seems to work, and I don't know of anything I did to trigger it not working. I'm hoping there's a simple solution to this, and I'm just dumb.
Thanks.

This might be way off, but it's something that's tripped me up in the past:
If you are using Sun's Java plugin, the first time you go to a site that has a particular Java applet, you may be asked to approve/reject a security request.
If you have clicked on any other windows while the request is first being loaded (which can take some time, because this is swing based), then the security dialog box does not pop to the top of the window stack, and doesn't add an entry into the task bar.
It appears that Java just doesn't work, but it's actually waiting for you to click "Yes". You can check this by hitting alt-tab and seeing if the Java coffee cup icon is one of the options.
- K

Help with JAI in java applet

I'm fairly inexperienced with java, but I'm hopeful someone here won't mind helping.
I am using netbeans and have a project to let a user upload files or scan them in with a usb scanner. I've imported icepdf to the libraries and referenced it in the jnlp file and it worked fine. I did the same with jai_windows-i586.jar and I get this error when trying to upload
Exception in thread "AWT-EventQueue-2" java.lang.NoClassDefFoundError: com/sun/media/jai/codec/SeekableStream
Caused by: java.lang.ClassNotFoundException: com.sun.media.jai.codec.SeekableStream
I expanded the jar file and found it contained an exe. jai-1_1_3-lib-windows.i586.jre.exe. I found that if I run that exe [(found here)|http://download.java.net/media/jai/builds/release/1_1_3/] on any pc locally, I will not get the errors on that pc.
Am I referencing it incorrectly?
<resources>
<j2se version="1.6+" href="http://java.sun.com/products/autodl/j2se" max-heap-size="1024m" />
<jar href="ScanAreaUI.jar" main="true" />
<jar href="icepdf-core.jar"/>
<jar href="jai_windows-i586.jar"/>
<nativelib href="JTwain-Native.jar" />
</resources>
Do I need to make the applet install the exe located in the jar? I've tried to find information on how to do that without much luck so far.
Thanks for any advice/help.

If it's not finding your "exe" file, then you have an OS path problem. You can either change your path variable in Windows or you can move that "exe" to a location where you already have a path defined. You do realize that when you use features of JAI that are not incorporated in to the JDK, you'll have to have the JAI package loaded on every machine you ever want to run your project.

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