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I would assume that by 231 he means 2^31, which is the limitation for a signed int.;
As for the question, what you are going to have to do is remember back to gradeschool, when we did longhand arithmetic.
1001
2009
----
3010
Write out psuedo code on how to do this, then implement it. isValidBigInt should be easy.
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TannerB wrote: I would assume that by 231 he means 2^31
this is fundamentaly different, and moreover, WRONG.
the higher value an unsigned int can take is (2^32)-1, which is 4 294 967 295.
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Thanks, must of had a brain fart when I read it.
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As far as I remember, there is only signed int in Java, so its maximum value would be (2^31)-1 (2,147,483,647).
My LinkedIn Profile
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I've got this here code I just started today for an assigment, it is all working (so I'm not asking you to do it for me :P). What this code does is it considers any @ to be a backspace and deletes the character before it. I was supposed to use indexOf() and substring() but I thought using regular expressions would be simpler, and a learning experience at the same time. I think my problem right now is that I have stared at it for too long. What I want is for the loop in main to be ran atleast once but it seems weird to have the while(checkForError(input)); ran and then have it ran again in the method fixErrors . Any thoughts on what I could do to fix this would be welcome. Other comments and critiques are always welcome.
Thanks,
Tanner
EDIT: Update at bottom.
import javax.swing.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class bruce_tanner_A3Q3
{
public static void main(String [] args)
{
String input;
do
{
input = getString("Enter a string");
printOutput(fixErrors(input));
}while(checkForError(input));
}
public static boolean checkForError(String input)
{
Pattern pattern = Pattern.compile("@");
Matcher matcher = pattern.matcher(input);
return matcher.find();
}
public static String getString(String input)
{
String tempString = JOptionPane.showInputDialog(input);
return tempString;
}
public static void printOutput(String tempString)
{
System.out.println(tempString);
}
public static String fixErrors(String tempString)
{
if(checkForError(tempString))
{
Pattern pattern = Pattern.compile("[^@][@?+]");
Matcher matcher = pattern.matcher(tempString);
while(matcher.find())
{
tempString = matcher.replaceAll("");
matcher = pattern.matcher(tempString);
}
pattern = Pattern.compile("@");
matcher = pattern.matcher(tempString);
tempString = matcher.replaceAll("");
return tempString;
}
return "This string is error free";
}
}
I'm not sure whether this was a flash of brilliance or not but it works.
New main code:
public static void main(String [] args)
{
String input;
for(input = getString("Enter a string"); checkForError(input); input = getString("Enter a string"))
{
printOutput(fixErrors(input));
}
printOutput("This string is error free");
}
New fixErrors:
public static String fixErrors(String tempString)
{
Pattern pattern = Pattern.compile("[^@][@?+]");
Matcher matcher = pattern.matcher(tempString);
while(matcher.find())
{
tempString = matcher.replaceAll("");
matcher = pattern.matcher(tempString);
}
pattern = Pattern.compile("@");
matcher = pattern.matcher(tempString);
tempString = matcher.replaceAll("");
return tempString;
}
modified on Monday, November 3, 2008 2:57 PM
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I have a Swing based application which consists of 5 classes.
Now I want to make the whole application as an exe file.
Can some one help me in this regard......
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do you use an IDE ? if yes, which ?
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you can download the jet engine exe file then u can attach the class files and then run which is very very useful jet is available at sun products
Ambedkar Golla
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Use this tool:
JSmooth
The downlodad URL is:
http://www.ej-technologies.com/download/exe4j/files.php
If you don't know the package method send a mail to me. [soief@qq.com]
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how to develop installation web application software using java(servlets,jsp),java script,mysql(database).
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I have this problem,
I need to represent set in the following form
[L,R]
where L is the left hand-bound of the set , and R is the right hand-bound
each of L and R are a collection of sets
for example
L= [{1},{2},{2,3}]
R=[{1,2,3},{2,3,4}]
[L,R]= [{ {1},{2},{2,3} } , { {1,2,3},{2,3,4} }]
how can i do this in java
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There are many ways that you could represent this depending on what you are trying to do. My initial thought is a 2 element array of sets of sets e.g.
Set s1 = new Set();
s1.add(1)
Set s2 = new Set();
s2.add(2)
Set s23 = new Set();
s23.add(3)
s23.add(2)
Set left = new Set{}
left.add(s1}
left.add(s2}
left.add(s23}
/*
* Prepare Right Side now
*/
Set[] allSets = new Set[2]()
allSets[0] = left;
allSets[1] = right;
Do the Sets in L and R have to be unique. Also why are you modelling the sets what do you expect to do with them. If it is a bit more rigid and you want to perform operations on the sets you may want to use a class to model them
e.g.
public Class LeftRightSet() {
private Set<set><string> left;
private Set<set><string>> right;
// Further manipulation classes
}
Hope this helps
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Hi all,
I need to find the coordinates of the selected item in my JList. I'd expect this line of code to be defined in swing, but it's not.
selectedItemY = [JList Name].getSelectedValue().getY();
Any suggestion?
Thanks
Naz
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How can I compile my java code without going to a DOS window?
Everything makes sense in someone's mind
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I use NetBeans IDE where every function is visually available. So you never need to use the cmd. You can download it for free.
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KMAROIS wrote: How can I compile my java code without going to a DOS window?
by using an IDE...
the best I ever used is definitely Eclipse:
Eclipse for J2SE[^]
Eclipse for J2EE[^]
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The RAD is better.
but not free.
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Hi,
I've followed this article (http://java.sun.com/developer/technicalArticles/J2EE/AJAX/[^]) to create a Java Servlet and retrieve data from it using AJAX. In this example the doGet method is automatically run and it gives me the required output, however I would like to have additional methods in this class returning different things that I can call on demand, how would I do this?
Thanks in advance
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Hi, I'm currently working on concerning a student record with guardians/parents... im using the java ee framework.. I'm having problems on retrieving the data on our database(MySQL).. Here is what i did.. i have created a class to retrieve those data from the database..
my problem is that whenever i retrieve that data in my jsp page, it only shows this Ljava.lang.String@123EGa something similar to this..
<small><br />
CLASS PLARENTS .. <br />
<br />
package com;<br />
import java.io.*;<br />
import java.sql.*;<br />
import javax.servlet.jsp.*;<br />
import javax.servlet.jsp.tagext.*;<br />
<br />
public class Parents {<br />
<br />
public String[] lastname;<br />
public String[] firstname;<br />
public String[] middlename;<br />
public String[] relation;<br />
<br />
private Connection connection = null;<br />
private Statement statement = null;<br />
private ResultSet rs = null;<br />
Connect con = new Connect();<br />
int count = 0;<br />
<br />
public Parents(){}<br />
<br />
public Parents(int idno) {<br />
int i = 0;<br />
try {<br />
Class.forName("com.mysql.jdbc.Driver").newInstance();<br />
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/sis",con.user,con.password);<br />
statement = connection.createStatement();<br />
rs = statement.executeQuery("SELECT * FROM guardians WHERE studidno='" + idno + "'");<br />
<br />
if (rs.last()) {<br />
count = rs.getRow();<br />
}<br />
<br />
lastname = new String[count];<br />
firstname = new String[count];<br />
middlename = new String[count];<br />
relation = new String[count];<br />
<br />
while (rs.next()){<br />
lastname[i] = rs.getString("lastname");<br />
firstname[i] = rs.getString("firstname");<br />
middlename[i] = rs.getString("middlename");<br />
relation[i] = rs.getString("relation");<br />
i++;<br />
}<br />
<br />
} catch (Exception e) {<br />
e.printStackTrace();<br />
}<br />
}<br />
<br />
<br />
public String[] getLastname(){return lastname;}<br />
<br />
public String[] getFirstname () {return firstname;}<br />
<br />
public String[] getMiddlename () {return middlename;}<br />
<br />
public String[] getRelation () {return relation;}<br />
<br />
}</small>
and this is what i placed in my jsp page..
<small> <% <br />
Parents p = new Parents(info.getIdno());<br />
for (int i = 0; i < p.getFirstname().length; i++ ) {<br />
%><br />
<tr bgcolor="#fefce3"><br />
<td><br />
<p id="info"><br />
<%= p.getLastname() %><br />
</p><br />
<p id="record">Relationship:<br />
<span id="relationship"><br />
<%= p.getFirstname() %><br />
</span><br />
</p><br />
</td><br />
<br />
</tr><br />
<tr><br />
<td> </td><br />
</tr><br />
>% } %></small>
Hi, I'm currently working on concerning a student record with guardians/parents... im using the java ee framework.. I'm having problems on retrieving the data on our database(MySQL).. Here is what i did.. i have created a class to retrieve those data from the database..
my problem is that whenever i retrieve that data in my jsp page, it only shows this Ljava.lang.String@123EGa something similar to this..
"according to what i have read on some searches, the best way to do it is by using data access objects..".. can anybody just an idea on how to do this using data access objects or give some sample codes for me to do this.. Im asking for an idea.. or any sample codes will do.. i have been working on this for about 2 days now, I've done so many researches and i haven't quite find any answer to my problem..
modified on Monday, October 27, 2008 9:23 PM
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Hi,
I am a new member in this forum. I am developing a website.In my website once a user logs in, he is made to view a number of links, the click on which takes them to a new site.
suppose my site is x.com. x.com have a number of url, ome among is a.com. clicking on a.com should allow the user to access search page in a.com site. What i need is when a user clicks on the link a.com from my site x.com, he should be automatically logged into the a.com site. the login info, cookies etc should should be passed programmatically.
Can some one help me to implement this.
Thanks in advance
veda
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Hi,
I have some problem in doing Jtable (I want the JTable to read the data from database) I wrote the code and it work with me in another project but Kow it didn't work I want some one to check this code if I miss some comma or thing in it.
The Code :
//=========================================
package Inventory;
public class cm1 {
private String tables;
public String selectData(String fields, String whereClause) {
if (whereClause == null && fields != null) {
return "SELECT " + fields + " FROM " + this.tables;
} else if (whereClause == null && fields == null) {
return " SELECT * FROM " + this.tables;
} else if (whereClause != null && fields == null) {
return " SELECT * FROM " + this.tables + " WHERE " + whereClause;
} else {
return "SELECT " + fields + " FROM " + this.tables + " WHERE "
+ whereClause;
}
}
//=========================================
public String deleteData(String whereClause) {
return "DELETE " + this.tables + " WHERE " + whereClause;
}
//=========================================
public void setDbTables(String table) {
this.tables = table;
}
//=========================================
public String insertQuery(AddPR p) {
return "INSERT INTO "
+ this.tables
+ " ( ITEMNUM,ITEMTYPE,LOCATION,MANUCODE,FXDASTNUM,MANUSRLNUM,COMMDATE,DESCRIPTION,STATUS,STATUSDATE,MODEL,MSRNUM,COMTYPE,USERNAME,TMSRV,PORT,IPADDRESS,PRICE,PRODUCTIONDATE,YEAR) VALUES ("+ p.getITEMNUM() + ", '" + p.getITEMTYPE() + "', '" + "', '" + p.getLOCATION() + "', '" + "','" + p.getMANUCODE() + "','" + p.getFXDASTNUM() + "', '" + p.getMANUSRLNUM() + "', '" + p.getCOMMDATE() + "', '" + p.getDESCRIPTION() + "', '" + p.getSTATUS() + "', '" + p.getSTATUSDATE() + "','" + p.getMODEL() + "','" + p.getMSRNUM() + "','" + p.getCOMTYPE() + "','" + p.getUSERNAME()+ "','" + p.getTMSRV() + "','" + p.getPORT()+ "','" + p.getIPADDRESS()+ "','" + p.getPRICE()+ "','" + p.getPRODUCTIONDATE() + "', '" +p.getYEAR();
}
}
//========================================="the end of the code"
please help me as soon as possible
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Hi Xiang,
I found, your program for Searching and replacing strings (TextRep.java) in a file very usefull. Thanks for posting it.
Explaing below a scenario which im working on :
1. My Program should read the file name, search string and string to be replaced from an xml file.
<cmvc>
<cmvcauto>
<filename>C:\cmvc\Readme.txt</filename>
<string>Following are the contents of this CD.</string>
<replace>Im chnaged : Following are the contents of this CD.</replace>;
</cmvcauto>
</cmvc>
2. Get the file, search for the existence of the string in tht file , replace the old one with the new string and save modified file in a diff location.
I thought of modifying your program to match my requirement. Since your program TextRep.java also takes a backup of the file....my issue of saving the modified file is also solved. I have a program to get the values from the xml file. Now im passing those values to ur program instead of args[0], args[1] and args[2].
i get the value of filename from xml file in the fashion :
NodeList textFNList = firstNameElement.getChildNodes();
System.out.println("First file name : " +
((Node)textFNList.item(0)).getNodeValue().trim());
Now i define a method "replaceString" and call it in the main program by passing the values that i get from the xml file :
NodeList textFNList = firstNameElement.getChildNodes();
System.out.println("First file name : " +
((Node)textFNList.item(0)).getNodeValue().trim());
//-------
NodeList lastNameList = firstPersonElement.getElementsByTagName("string");
Element lastNameElement = (Element)lastNameList.item(0);
NodeList textLNList = lastNameElement.getChildNodes();
System.out.println("Search String : " +
((Node)textLNList.item(0)).getNodeValue().trim());
//----
NodeList ageList = firstPersonElement.getElementsByTagName("replace");
Element ageElement = (Element)ageList.item(0);
NodeList textAgeList = ageElement.getChildNodes();
System.out.println("Replace string " +
((Node)textAgeList.item(0)).getNodeValue().trim());
replaceString(((Node)textFNList.item(0)).getNodeValue().trim(), ((Node)textLNList.item(0)).getNodeValue().trim(), ((Node)textAgeList.item(0)).getNodeValue().trim());
Below is the method defenition and the defenition is your program :
public static void replaceString(String fileName, String match, String replacingString)
{
try
{
// make 32k buffer for output
StringBuffer strOutput = new StringBuffer(32768);
// read input file into a byte array
//byte[] pInput = ReadFile(args[0]); This is the original line from your program
byte[] pInput = ReadFile((filename);
// make a backup copy
WriteFile(fileName +".backup.copy",pInput);
String strInput = new String(pInput);
Doing this modification, i get the below error :
C:\Documents and Settings\Administrator\Desktop\CMVC_Automation>javac fullSearch.java
fullSearch.java:107: cannot find symbol
symbol : method ReadFile(java.lang.String)
location: class fullSearch
byte[] pInput = ReadFile(fileName);
^
fullSearch.java:109: cannot find symbol
symbol : method WriteFile(java.lang.String,byte[])
location: class fullSearch
WriteFile(fileName +".backup.copy",pInput);
^
2 errors
My program starts with these lines :
import org.w3c.dom.Document;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
import java.io.*;
import java.util.*;
Would really apreciate, if you could help on those errors. Thanks.
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Hi, I successfully send email with the following code in English. However, if the message and the subject title are in other characters, everything becomes question marks and the subject title says something like ...ANSI...3F=3F=3F...
How do I set the character encoding to utf-8, for example? Thanks.
<br />
try<br />
{ <br />
Properties props = new Properties(); <br />
Session sendMailSession; <br />
Transport transport; <br />
sendMailSession = Session.getInstance(props, null); <br />
props.put("mail.smtp.host", SMTP_CLIENT); <br />
Message newMessage = new MimeMessage(sendMailSession); <br />
newMessage.setFrom(new InternetAddress(EMAIL_FROM)); <br />
newMessage.setRecipient(Message.RecipientType.TO, new InternetAddress(strEmail)); <br />
newMessage.setSubject(SUBJECT); <br />
newMessage.setSentDate(new Date()); <br />
strMsg = "Dear " + RS.getString("FIRST") + " " + RS.getString("LAST") + ",";<br />
strMsg += "\n\n";<br />
strMsg += [MESSAGE IN CHARACTERS OTHER THAN ASCII];<br />
newMessage.setText(strMsg); <br />
transport = sendMailSession.getTransport("smtp");<br />
transport.send(newMessage);<br />
} <br />
catch(MessagingException m) <br />
{ <br />
...<br />
}
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Can anyone tell me different between JRE 1.6 and JRE 1.5? And what is "Keep temporary files on my computer" option? When I un-check this option, my applet runs ok. But If I check this option, my applet sometimes hangs up. So, I guess this error is come by "Keep temporary files on my computer" option. JRE 1.5 doens't have this option.
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don't sun provide a Release Note Document ?
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