PropertyChangeListener for an int value

What I want is that a few variables update accordingly when one specific int's value changes. I heard PropChListener would provide this feature (well, not specifically for integers, but..), and so I tried it.
intVariable.addPropertyChangeListener(this);but at compile I get "int cannot be dereferenced". How'd I get it working? Am I completely wrong?

You need to convert the int to an Integer.

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Can't read int value

import java.io.*;
class binary
     public static void main(String args[])
          BufferedReader br;
          int ch=0;
          br = new BufferedReader(new InputStreamReader(System.in));
          System.out.println("enter value");
          try
               ch = (int)br.read();
          catch(IOException e)
               System.out.println("Exception Caught");
          System.out.println("the value entered is :" + ch);
}the read method used above reads an character and returns it integer value and if we want to read an integer value how to do so, i tried it in the above code but it doesn't work
is there any specific function for reading int values or we need to use the ByteStream classes instead of the Character ones
plz reply

thanks it worked
i read my number using the readLine() method as a
String and then converted it back to an int value
ut is there no method by which i could read values as
int from the console n not have to do the conversion
part.plz heply guys

Public int indexOf(int ch, int fromIdx) doesn't work for some decimal value

I have tested two strings below. These two string are identical, except the first string has a char ', which has a decimal value of 131. And the second string has a char 'À', which has a decimal value of 192. I am expecting the same output, which is 11, but I got -1 for the test I did using the first string. In the API for public int indexOf(int ch, int fromIndex), values of ch is in the range from 0 to 0xFFFF (inclusive). It is highly appreciated if anyone could provide any insights on why -1 returned when the first string is tested. Thank you in advance.
String strHasDecimal131 = "Test value , it has a decimal value of 131";
String strHasDecimal192 = "Test value À, it has a decimal value of 192";
int badDecimal = 131;
int idxBadDecimal = strHasDecimal131.indexOf( badDecimal, 0);
System.out.println( "index of Bad Decimal: " + idxBadDecimal );
The output is: index of Bad Decimal -1
int badDecimal = 192;
int idxBadDecimal = strHasDecimal192.indexOf( badDecimal, 0);
System.out.println( "index of Bad Decimal: " + idxBadDecimal );
The output is: index of Bad Decimal: 11

Thank you everyone for your inputs. Following are the print statements and the output: for character '' and ' À':
System.out.println((int)'\u0083' + ", " + (int)'\u00C0' + " print decimal value" );
Output: 131, 192 print decimal value
System.out.println((char)'\u0083' + ", " + (char)'\u00C0' + " print character value" );
Output: ?, À print character value
According to Latin-1 Supplement table, the first char in the output would have the appearance of , instead it has the appearance of ?
System.out.println( (int)'' + ", "+ (int)'À' + " print integer value");
Output: 402, 192 print integer value
I also have tried to print out the decimal value of following char: � , according to Latin-1 Supplement table, these char has decimal value of 128 through 135 and hex value 0x0080 through 0x0087. And the output from java println is: 8364 65533 8218 8222 8230 402 8224 8225.
System.out.println((int)'' + " " + (int)'�' + " " + (int)'' + " " +(int)'' + " " + (int)'' + " " +(int)'' + " " + (int)'' + " " + (int)'' );
As I did before, I print out character of decimal value of 128 through 135
System.out.println((char)128 + " " + (char)129 + " " + (char)130 + " " +(char)131 + " " + (char)132 + " " +(char)133 + " " + (char)134 + " " + (char)135 );
Output: ? ? ? ? ? ? ? ?
Not sure why java prints character for decimal value of 128 through 159 differently from what appears in the Latin-1 Supplement table. Any of your inputs are appreciately.

How to get Int value from request.getParameter()?

Hi all,
I have a integer value which is passed from one page to another page.
i am geting this value in the next page using
request.getParameter().
Eg.
Suppose value of "i" in page1 is 32, i pass this as hidden variable to next page.
<input type="hidden" Value="<%=i%>" NAME="limit">
in page2, i fethch this value to a variable by name "limit"
String limit=request.getParameter("limit");
but, since value stored in limit is int, i can't assign it to string.
i can't use request.getParameter for int values.
How to solve my problem.
I know it is simple,
Pls. help me
Regards
ASh
String limit=request.getParameter("limit");

String limitSTR = request.getParameter("limit");
int limit = -1;
if (limitSTR != null) limit = Integer.parseInt(limitSTR);

How to check for null int/null Date

Heres the situation, there is an interface accepting an int value and a time/date that are not required(and are not set to anything automatically, i have no control over that part unfortunately), but I need to set up some sort of null/has value type of check to execute the setter when it does have a value, and ignore it when it doesnt. I am currently getting null pointers. here is my current set up:
//throws null pointer as set up below, I am assuming I might want to eliminate the "getDate" off of the end and that might clear it up.
if(data.getDate().getTime() != null)
          tempData.setDate(data.getDate().getTime());
//Not sure on this one yet, the value doesn't get set to anything so I am assuming it automatically gets assigned something like -1.
if(data.getId() >= 0){
          tempData.setId(data.getId());
          }

tsdobbi wrote:
I know data isnt null because it goes through a bunch of other tempData.set(data.get) items prior to hitting a snag on the above date I mentioned, when there is no value input for the date. and that particular null check I do there, does not work because it throws a null pointer in the if statement itself.
i.e. it traces the null pointer to
(if data.getDate().getTime != null) //this is the line the null pointer traces to.{color:#3D2B1F}if data is not null, then it must be the case that data.getDate() is null. Now that's what I call logic. W00t!{color}

How do I know if I can convert a String value to an int value or not?

Hi,
I want to know how to make the judgment that if I can convert a String value to an int value or not? Assume that I don't know the String is number or letters
Thank you

Encephalopathic wrote
Again, why?One of the problems (have been dued) in my codelab asks us to write a class as follow
Write a class definition of a class named 'Value' with the following:
a constructor accepting a single integer paramter
a constructor with no parameters
a method 'setVal' that accepts a single parameter,
a boolean method, 'wasModified' that returns true if setVal was ever called for the object.
a method 'getVal' that returns an integer value as follows: if setVal has ever been called, it getVal returns the last value passed to setVal. Otherwise if the "single int parameter" constructor was used to create the object, getVal returns the value passed to that constructor. Otherwise getVal returns 0.
The setVal(int y) returns nothing, so how do I know whether it has been called or not?
Thank you

Comparing a single int to more than one int value?

Hi is there a way to compare a single int value amongst several ints in one go?
i know i could do if statements that can compare each int one by one but i was wondering if there is an easier way? like comparing all values amognst eachother
somthing like
int i;
int a,b,c,d,e,f,,g;
//ints a-g assigned some random numbers
if(i == a,b,c,d,e,f,g)
      //do somthing here
}

i found out a way. i tried this way by using nested for loops and an if statement that compares every single value amongst eachother
for(int q=0; q < 5; q++)
            ran[q] = (int)(java.lang.Math.random()*52);
        for(int x = 0; x < 5;x++)
            for(int z = 0; z < 5; z++)
                if(x != z && ran[x] == ran[z])
                    ran[x] = (int)(java.lang.Math.random()*52);
        }

New solution for Limit the value in JSpinner with changable max/min value

I have ever stuck with a problem like that :
1. My application need to get two int value A and B that user input.
I use two JSpinner with Number format model.
named in jSpinnerFrom (A value get from) jSpinnerTo (B value get from)
2. The request is that :
two value can be any Integer, But the value of (B - A) can not more than 1000.
I use changeListener added into the JSpinner, when use set value make (B-A) larger than 1000, I set value back.
But when user press mouse on arrow button, the value will be increase automaticaly, and at last the value can not set back that make (B-A) not larger than 1000.
3. So I get the BasicArrowButton of the jSpinnerFrom and jSPinnerTo,
and add a mouselistener on the arrowbutton. When mouseReleased, then chen the value (B-A), if it is larger than 1000, then set it back the proper value.
Thus I can make the min/max value in the JSpinner be changable, and limit the two input value be in range of 1 - 1000
Post this wish be help for any one has thus familar request.
Good Luck!!

Something like this might work
import javax.swing.*;
import java.awt.*;
import javax.swing.event.*;
class Spin extends JFrame implements ChangeListener
JSpinner spinner1;
JSpinner spinner2;
JPanel jp;
public Spin()
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(200,75);
    setLocation(400,300);
    spinner1 = new JSpinner(new SpinnerNumberModel(1000, 1000, 9999, 5));
    spinner1.addChangeListener(this);
    spinner2 = new JSpinner(new SpinnerNumberModel(0, 0, 1000, 5));
    jp = new JPanel();
    jp.add(spinner1);
    jp.add(spinner2);
    getContentPane().add(jp);
public void stateChanged(ChangeEvent ce)
    int s1 = ((Integer)spinner1.getValue()).intValue();
    jp.remove(spinner2);
    spinner2 = new JSpinner(new SpinnerNumberModel(s1-1000, s1-1000, s1, 5));
    jp.add(spinner2);
    validate();
public static void main(String[] args) {new Spin().setVisible(true);}
}

Output of int value to char

hi,
I have written the following code
class LiteralTest
     public static void main(String[] args)
          System.out.println("Hello World!");
          int true1=100;
          float flt = 17.2345678f;
          short sh = (int)500;
          char a=0x892;
          char b=982;
          char c=(char)70000;
          char d=(char)-98;
          System.out.println(a + " -- "+b+ " -- "+c+ " -- "+d);
the output is
Hello World!
Please explain why the values are '?' and not the actual values?
Deepali

And why are you specifying a character with a
negative number?Casting a negative number to a (unicode) char is valid. For example
            int c = -1279;
            System.out.println(c);
            char ch = (char)c;
            System.out.println(ch);prints the 'ﬁ' character which has unicode value 0xfb01.

Execute BAPI for different input values and dispaly data in a table

Hi all,
I have a specific problem about executing BAPI multiple times for different input values and didplay result in a table.
I am using the code similar to the following logic.
Bapi_Mydata_Input in = new Bapi_Mydata_Input();
wdContext.nodeBapi_Mydata_Input().bind(in);
String in = wdContext.currentperdataElement.getnumber();
in.setDestination_From(10)
wdThis.wdGetMydataComponentController().executeBapi_Mydata_Input();
in.setDestination_From(20)
wdThis.wdGetMydataComponentController().executeBapi_Mydata_Input();
in.setDestination_From(30)
wdThis.wdGetMydataComponentController().executeBapi_Mydata_Input();
And I want to display the data in a single table. I want the result in a table for Bapi execution based on input parameters passed 10,20 30.
But I am getting the table data only for the input parameter 30.I mean its actually display the data in table only for the last input parameter.
So May I ask you all if you know the solution for this problem.PLease advise me with some tips .or sample code is very much appreciated.I promise to award points to the right answer/nice advises.
Regards
Maruti
Thank you in advance.

Maruti,
It seems that WDCopyService replaces content of node, rather then adds to content.
Try this:
Bapi_Persdata_Getdetailedlist_Input frelan_in = new Bapi_Persdata_Getdetailedlist_Input();
wdContext.nodeBapi_Persdata_Getdetailedlist_Input().bind(frelan_in);
final Collection personalData = new ArrayList();
String fr1 = wdContext.currentE_Lfa1Element().getZzpernr1();
frelan_in.setEmployeenumber(fr1);
wdThis.wdGetFreLanReEngCompController().executeBapi_Persdata_Getdetailedlist_Input();
WDCopyService.copyElements(wdContext.nodePersonaldata(), wdContext.nodeNewPersonaldata());
for (int i = 0, c = wdContext.nodePersonaldata().size(); i < c; i++)
personalData.add( wdContext.nodePersonaldata().getElementAt(i).model() );
String fr2=wdContext.currentE_Lfa1Element().getZzpernr2();
frelan_in.setEmployeenumber(fr2);
wdThis.wdGetFreLanReEngCompController().executeBapi_Persdata_Getdetailedlist_Input();
WDCopyService.copyElements(wdContext.nodePersonaldata(), wdContext.nodeNewPersonaldata());
for (int i = 0, c = wdContext.nodePersonaldata().size(); i < c; i++)
personalData.add( wdContext.nodePersonaldata().getElementAt(i).model() );
wdContext.nodeNewPersonalData().bind( personalData );
Valery Silaev
EPAM Systems
http://www.NetWeaverTeam.com

Mapping a key string to the KeyEvent int value

/** Returns the int value of a key
* @param the String representing the key. example "SHIFT" for the shift key
* @return KeyEvent.VK_keyName
public static int mapKeyCode(String keyName) {
// we don't have access to an instance of KeyEvent!!!
Class.forName("java.awt.event.KeyEvent").getDeclaredField("VK_"+keyName).getInt(obj..@#@#@
//+ exception handling
}

public int keyTyped( KeyEvent event ) {
try {
     return java.lang.Integer( String.valueOf( event.getKeyChar() ) );
} catch ( NumberFormatException nfe ) {
     System.err.println( "NumberFormatException: " + nfe.getMessage() );
     return( 0 );
}

Formatting an int value

I have an int ID which is a unique identifier within my code,
within lists I would like consecutive IDs to appear as 001,002, ... 009,010 etc
how do I go about adding preceding 0 placeholders to an int value?
The value must remain as an int, my specs do not permit me to parse it to a String value
I do remember coming across the methodology to perform this task a while back, but I cannot remember where I found it.
example:
int ID = 000; // initialize with '0' value, I want 3 places in the final value
ID = ++ID; // increment the ID within the constructor
System.out.print("ID = " + ID); // test the current value of ID
results in:
ID = 1
desired result would be
ID = 001
either direct 'How-To' or appropriate linkage would be appreciated

That was exactly what I had been looking for.
I knew I'd come across it when coding for a previous task, but for
the life of me I couldn't work out where <red face> I was missing
the "f" when I did my searches <doh>
I assume that if I then print the result to a file (with the preceding 0s)
that the placeholder 0s will be trimmed upon readback (as in my first
example), which will suit the specs of the task perfectly.
Many thanks

How to set different bgcolors for rows int HtmlDatatable?

I have JSF HtmlDataTable on my page. I need to fill rows in table by different colors, according to row's data, but I can't find any method for it...... Should I use JavaScript in this case?

Due to your words, I tried it myself once. And it just works?
Here is the dummy example:
JSF<h:form>
    <h:dataTable binding="#{myBean.table}" value="#{myBean.list}" var="item"
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        <h:column>
            <h:outputText value="#{item.name}" />
        </h:column>
        <h:column>
            <h:outputText value="#{item.value}" />
        </h:column>
        <f:facet name="footer">
            <h:panelGroup>
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                    disabled="#{myBean.table.first == 0}" />
                <h:commandButton value="prev" action="#{myBean.pagePrevious}"
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                <h:commandButton value="last" action="#{myBean.pageLast}"
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        </f:facet>
    </h:dataTable>
</h:form>MyBeanpackage mypackage;
import java.util.Iterator;
import java.util.List;
import javax.faces.component.html.HtmlDataTable;
public class MyBean {
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    private HtmlDataTable table;
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        loadList();
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        list = new ArrayList<MyData>();
        int i = 0;
        while (i++ < 20) {
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        table.setFirst(0);
    public void pagePrevious() {
        table.setFirst(table.getFirst() - table.getRows());
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        table.setFirst(table.getFirst() + table.getRows());
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        int rows = table.getRows();
        table.setFirst(count - ((count % rows != 0) ? count % rows : rows));
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            if (iter.hasNext()) {
                rowClasses.append(",");
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private Integer value; // + getter + setter
public MyData(String name, int value) {
    this.name = name;
    this.value = new Integer(value);
// + no-arg constructorIn the generated source I see in every page the same <tr class=""> value as the MyData#getName().

How to change double i = Math.random(); value to (int) value

I am trying to find out how to convert a given double value to integer, which is, to conver double myNumber = Math.random() to (int) value. Here is the sample program look like this.
Thank you for the help.
import javax.swing.JOptionPane;
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public static void main(String[] args)
int upperLimit = Integer.parseInt(JOptionPane.showInputDialog
(null, "Enter the upper range integer."));
double myNumber = Math.random();
//Test of Random numbers.
System.out.println("The Upper random number limit is: " +
myNumber * upperLimit);
} //End of main.
} // End of class.

Not sure exactly what you want and why you want to change the double to an int. I'm assuming by this you want to generate random integers, from 1 to the upper limit the user enters? If so, this is how I would do it:import java.util.*;
import javax.swing.*;
public class Numbers
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        Random r = new Random();
        int myNumber = r.nextInt(upperLimit) + 1;
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}

Keeping track of an int value when server is stooped

Hi
In my JSP custom tag I have an int value which is used to keep track of the number of people that have visited the site. If the server was to be stopped or if it crashes is there any way where the int value can be stored and retrieved when the server starts up again? I am using tomcat but am reluctant to write to a text file whenever the int value is incremented for efficiency purposes. IF the server is stopped would there be any possible ways to store the number (it would be ok to write to text file just before stopping of tomcat happens).
Thx
Bal

yes....
you can do using context listeners....
in the start of context listeners read from the file and add to context ... and when the context becomes inactive write to a file....
for that you should use tomcat4.01 ... cause only tat has servlet 2.3 implementaion.
if you are not using tat .. write to the file every 10 minutes .. atleast you will have the latest update of the counts when something crashes......................

PropertyChangeListener for an int value

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