Array dosen't work as mutiple return value

I use WL8.11 as server and C#.NET as client, and have following problems:
1. Cannot return an array as out parameter, though I wrote a holder as example
given by bea document
2. I wrote a method which return an array of custom data type, it worked well.
but if the method had a out parameter as well as a return array of custom data
type, it failed
Who can help me with the two problems, thanks!!!

Xue,
These are some of the issues we need to be careful with when interoperating J2EE
and .NET. We are building some webservices in our company that do this kind of
stuff.
First of all, from my experiece, I found that using out parameters is a bad idea
when objects need to be serialized as in the case of web services. It makes your
app very inefficient for non-trivial load.
Secondly, the objects need to be 'serializable'. For the same reason, returning
a java ResultSet will not work.
The approach we are taking for now is to use the lowest common denominator in
both the worlds. For example, we don't pass around .NET DataSet objects (which
you could do if you have .NET consumer and .NET producer).
So the short answer is, unless we use the lowest common denominators, it is hard
to make the web services talk. There could be other approaches other people are
taking.
You might be interested in taking a peek at ws-interop spec that is getting ready
to address some of these issues.
-Anant
"Xue Yu" <[email protected]> wrote:
>
I use WL8.11 as server and C#.NET as client, and have following problems:
1. Cannot return an array as out parameter, though I wrote a holder as
example
given by bea document
2. I wrote a method which return an array of custom data type, it worked
well.
but if the method had a out parameter as well as a return array of custom
data
type, it failed
Who can help me with the two problems, thanks!!!

Similar Messages

FINDING MEDIAN FOR AN ARRAY OF INTS WITH EVEN NUMBER OF VALUES

okie dokie fellas i know this has got to be easy but i hjave been sittin at my comp forever workin on projects that are due and my head isn't all there anymore...could someone please clue me in on how im supposed to write the logic to find the median of an array of integers if the array contains an even number of values...I know I have to average the 2 values on either side but i cant figure it out at all...sorry i know its dumb but thnaks to anyone who helps
package pgm3deClercqMatt;
* @author Owner
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.text.*;
public class ExamStatistics
     public static void main(String[] args)
          DbConnection db = new DbConnection("pgm3");
          boolean moreRecords;
          String query = "SELECT * FROM pgm3Data ORDER BY ExamGrade";
          ResultSet rs = db.processQuery(query);
          int nbrGrades = 0;
          ResultSetMetaData rsmd = null;
          try
               rsmd = rs.getMetaData();
          catch(SQLException sqlex)
               JOptionPane.showMessageDialog(null, "SQLException getting ResultSet data or metadata");
               System.exit(0);
          int s[] = new int[200];
          DecimalFormat decimal = new DecimalFormat("#,##0.00");
          int n = 0, aboveNinety = 0, numberAboveNinety = 0;
          double sum = 0, avgGrade = 0, medianGrade = 0;
          try
               moreRecords = rs.next();
               if(!moreRecords)
                    JOptionPane.showMessageDialog(null, "pgm3Data Result Set is Empty.");
                    System.exit(0);
               while(moreRecords)
                    s[n] = rs.getInt(1);
                    n++;
                    moreRecords = rs.next();
               }// end of while loop
               System.out.println("n = " + n);
               System.out.println("s[0]= " + s[0]);
               System.out.println("s[n-1]= " + s[n-1]);
               //FIND AVERAGE OF ARRAY
               for(int j=0; j<n; ++j)
                    sum += s[j];
                    avgGrade = sum/n;
               //FIND NUMBER OF GRADES ABOVE OR EQUAL TO 90
               for(int j=0; j<n; ++j)
                    if(s[j]>=90)
                         numberAboveNinety++;
               //FIND MEDIAN EXAM GRADE
               for(int j=0; j<n ; ++j)
                    if(Math.abs(medianGrade - Math.floor(medianGrade))<1.e-10)
                          medianGrade = s[(j+1)/2];
                    else
                         medianGrade =    <HERE IS WHERE THE PROB IS
          }// end of try block
          catch(SQLException sqlex)
               JOptionPane.showMessageDialog(null, " SQLException getting ResultSet data or metadata");
               System.exit(0);
          String output = "";
          output = "Number of Exam Grades: " + n;
          output += "\nHighest Exam Grade: " + maxOfArray(s, n) + "\nLowest Exam Grade: " + minOfArray(s, n)
                    + "\nAverage Grade: " + decimal.format(avgGrade) + "\nNumber of exam grades above 90: "
                    + numberAboveNinety + "\nMedian Exam Grade: " + medianGrade;
          JOptionPane.showMessageDialog(null, output);
          System.exit(0);
     }// end of main
     static int maxOfArray(int z[], int n)
          int j, max = z[0];
          for(j=1; j<n; ++j)
               if(z[j]>max)
                    max = z[j];
          return max;
     static int minOfArray(int z[], int n)
          int j, min = z[0];
          for(j=1; j<n; ++j)
               if(z[j]<min)
                    min = z[j];
          return min;
}// end of ExamStatistics
class DbConnection
     //     class DbConnection creates and manages the db connection,
     //     processes queries, and returns result sets for processing
     private Connection connection = null;
     private String url="jdbc:odbc:";
     private Statement statement;
     private String username = "";
     private String password = "";
     private ResultSet rs;
     private int nbrResultSets = 0;
     //     Constructor Argument is the registered name of the database
     DbConnection(String dbName)
          try
          {// load driver to allow connection to database
               Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
               connection = DriverManager.getConnection ((url+dbName), username, password );
          catch (ClassNotFoundException cnfex)
               fatalError("ClassNotFoundException on connection attempt");
               System.exit(0);
          catch (SQLException sqlex )
               fatalError("SQLException -- Unable to Connect to db");
               System.exit(0);
     } // end of constructor
     ResultSet processQuery(String query)
     //     process a single SQL query and return the resulting data set
          rs = null;
          try
               statement = connection.createStatement();
               rs = statement.executeQuery(query);
          catch (SQLException sqlex)
               fatalError("SQLException on query or processing");
          return rs;
     void endConnection()
          try
               connection.close();
          catch (SQLException e)
               fatalError("SQLException on attempt to close connection");
     //     simple local fatal error handler
     private void fatalError(String msg)
          JOptionPane.showMessageDialog(null,msg);
          System.exit(0);
} // end of class DbConnection

sorry to anyone who thinks what i'm doing is a joke
first of all i'm a student and secondly i'm taking
java in a summer session so things don't get
explained as well as they should. And how is this our problem?
I'm doing the best
i can. The for loop was because the array that I
defined to hold 200 values was being filled by a
database with a supposed unknown number of values but
less than 200 so i waslooping through to get each
value and put it in order and the conditional
statement was supposed to test to see if the incoming
median was an integer and was in the final write-up
put into it's own boolean method returning false if
there was no median and you needed to take the
average of the next lowest and highest values. BThere's always a median. The definition I sent you tells you what it is.
But
thnak you very much to the people that actually help
on here and don't try to bash people who have put
effort into writing their code, however shitty it may
look to them. You can't control what people say about your stuff. Everyone who criticizes your work isn't making a personal attack. They're telling you something that you should be learning from. Your problem is that you can't separate yourself from your work.
No one knows absolutely everything and
people who decide to talk down on others when they
are using this forum as a last resort need to grow
up.Grow up? That's what you need to do. If you think for a moment that you'll never be criticized once you leave that ivory tower you're sadly mistaken. You need to figure out how to separate yourself from your code.
%

UML notation: Class operation return value multiplicity

Hallo,
how would you write function from example below using UML notation on implementation level, please:
class Coin {
public String[] getSideNames() {
return new String{ "Odd", "Even" };
}Multiplicity in return value is troubling me. I've tried +getSideNames( ) : String [ 2 ] but my tool just created new class named "String[2]" :-( To be precise I know that return value of function is array of MyClass with one or more element (1..*) so created class name was "MyClass[1..*]" -- nasty name to pass to javac isn't it? :-)
Is is possible to write multiplicity of return value this way? I couldn't find anything in omg's "UML: supertructure document" :-( I am not telling that it's not written there :-)))
Thank You.

jschell>
Unfortunately [n] behaves in same fashion as [*] =>
creating class named MyClass[1..n]" :-(
duffymo> what's the point?
this was only sample, real application is far more
complex than that. Even "nature" of result was just
made up. How am I or anyone else who responds supposed to know that?
>
duffymo> you can have cardinality in a class diagram
that shows exactly two values are available.
yup, i ended like that but there's still problem coz
return value class is "Object[]" :-(Sounds like a bad design, but I haven't seen the code, so I can't tell.
duffymo> personally, i don't think that exposing the
side names as ...
"side names" were just example :-) IMHO there are
certain situations where one could say "screw the
abstraction" :-D E.g. for final classes from one
package that cooperate on single time critical task.
:)"screw the abstraction" - good luck as an object-oriented designer with that attitude.
Either you're doing real-time work where time really is critical, or you're just another yutz who is congratulating himself on recognizing a time critical task without doing profiling or getting any real data. (A common mistake.) The maintainence and development time might be more critical here.
Gotta admit that I'm not much interested in commenting on your poor approximation of the real problem.
%

Execution flow doesn't wait for return values

I have created JNI wrappers for existing dlls. However I'm getting weird behavior. My Java function calls a c function which communicates with an old mainframe. If I retrieve one row at a time its fine but if I do a loop the virtual machine crashes. Sometimes, if I add an empty loop for (30000 iterations) then its fine. Its like java is already trying to retrieve the next row while the first row is still being printed on my screen. I've tried adding synchronized in case the dlls where multi-threaded but it has not made a difference. Is there any way to control the execution flow so that it can't go to the next line until the values are truly returned from the c dll.
thanks
MA

There are many function being called on the native side. Since I didn't want to modify the native side
(because the old dlls are used by another application), I added my own dll as an intermediary between the old c dlls and the java side.
To fix the problem I am having, I've heard of another project where the native side would write the returned values to a file and only once the file is written can the Java side continue. Is this the only way to control the execution flow?
Right now I have about 5 empty loops which run to 100000 and things work most of the time. But I would prefer to find a way to say wait until the values are returned correctly.
Essentially, what I'm doing is
for (int i=1;i<10; i++){
   test.init(Integer.toString(i),Integer.toString(i),"english desc"+ Integer.toString(i),"french desc"+ Integer.toString(i));
   test.execute(test.ActionAdd);
}This is supposed to add one row with four fields. I'm just putting junk for the test. If I call the two main lines
test.init(Integer.toString(i),Integer.toString(i),"english desc"+ Integer.toString(i),"french desc"+ Integer.toString(i));
test.execute(test.ActionAdd);just once it works fine but if I loop them then it crashes after a few loops. If I put a loop as shown below then it works fine. This is part of the code when I'm adding. Is it being looped 10 times from the code above.
jsession.scanTable(table,errorlist);
            rtc = table.getRecordCount(errorlist);
            if (rtc > 0)
            publish(rtc+" records found.");
                for(int i = 1; i <= rtc; ++i)
                    for (int j = 0; j < ElementName.size();j++)
                        publish((String)ElementName.get(j)+ ": " + table.getFieldByName((String)ElementName.get(j),i,errorlist));
                        for (int k = 0; k<100000;k++);
            else
                publish("No records found.");
            }In the code, when the rows are added, I print them out just to make sure they were added correctly. This is where I got the idea that the Java code was not in synch with the native side because it would crash while writting out a line but it didn't happen every time at the same place.
This is the function getFieldByName
public String getFieldByName (String p_FieldName, int p_LineNum, ErrorList p_Errors)
          String retval = "";
          int ret;
          try
               p_FieldName = prepareFieldName(p_FieldName);
               retval = new String();
               ret    = 0;
               if (this.ptrTableView == NOT_SET)
                    p_Errors.addMessage(p_Errors.SEV_SYSTEM_ERROR(), "Table View Pointer not set");
                    throw (new Exception());
               // allocating string buffer for value returned
               StringBuffer m_FieldValue = new StringBuffer();
               // determining length of value
               int m_length[] = {0};
               ret = gti.GetFieldLen(this.ptrTableView, p_FieldName, m_length, eb.getErrorBlockPtr());
               if (m_length[0] == 0) m_length[0] = 100;
               m_FieldValue = new StringBuffer(m_length[0]);
               // get line field
               ret = gti.GetLineField(this.ptrTableView, p_FieldName, p_LineNum, m_FieldValue, eb.getErrorBlockPtr());
               if (ret != 0)
                      p_Errors.addMessage(p_Errors.SEV_ERROR(), "Error retrieving field value ("+p_FieldName+")");
               else
                      retval = m_FieldValue.toString();
          catch (Throwable t)
               p_Errors.addMessage(p_Errors.SEV_ERROR(), "Error retrieving field value ("+p_FieldName+")");
          return retval;
    }The main functions are
GetFieldLen
GetLineField
They go to the native side through my dll which wraps the old dlls.
Here are is one of the main functions in my dll. I also have the source for the functions they are calling but they are calling other functions which are calling other functions. There is a lot of code . Yes, they use arrays.
JNIEXPORT jint JNICALL Java_advantagewrapperspk_GtiNative_GtiGetLineField
(JNIEnv *env, jclass cls, jint p_tableViewPtr, jstring VIEWFIELDNAME, jint VIEWFIELDNUM, jobject VIEWFIELDVALUE, jint iErrBlockPtr)
     //printf("\n\nGtiGetLineField in C:\n");
     jint iResult = 0;
     char *temp1 = (*env)->GetStringUTFChars(env,VIEWFIELDNAME,0);
     char *temp2 = (*env)->GetStringUTFChars(env,VIEWFIELDVALUE,0);
     iResult = GtiGetLineField(p_tableViewPtr,temp1,VIEWFIELDNUM,temp2,iErrBlockPtr);
     //printf("VIEWFIELDNUM %d ",VIEWFIELDNUM);
     //printf("\ntemp1 %s ",temp1);
     //printf("\ntemp2 %s ",temp2);
     (*env)->ReleaseStringUTFChars(env,VIEWFIELDNAME,temp1);
     if (temp2 == 0)      return iResult;
    if (temp2 != NULL)
            cls = (*env)->GetObjectClass(env,VIEWFIELDVALUE);
            jmethodID mid = (*env)->GetMethodID (env,cls,"append","(Ljava/lang/String;)Ljava/lang/StringBuffer;");
             if (mid == 0) return iResult;
             jstring sfinal = (*env)->NewStringUTF (env, temp2);
            (*env)->CallObjectMethod(env,VIEWFIELDVALUE,mid,sfinal);
          if (VIEWFIELDVALUE != NULL) (*env)->ReleaseStringUTFChars(env,VIEWFIELDVALUE,temp2);
     //(*env)->ReleaseStringUTFChars(env,VIEWFIELDVALUE,temp2);
     return iResult;
}This calls
* Function Name : GtiGetLineField()
* Description   : Retrieves the value of a line field in a table view
* Parameters    : pTableViewPtr pTableView--the table view from which to
*                                           retrieve the value of a line
*                                           field
*                 VIEWFIELDNAME szFieldName--the name of the line field
*                                            whose value is returned
*                 VIEWLINENUM iLineNum--number of line from which to retrieve
*                                       field value. Lines are numbered
*                                       beginning with 1.
*                 VIEWFIELDVALUE szFieldValue--returns the value of the
*                                              line field
*                 ErrBlockPtr sourceeb--error context info from calling
*                                       function
* Return values : int--returns RCT_RETURNOK, RCT_WARNCORECONNECT, or
*                      RCT_FAILCORECONNECT
* Modifications : REH - 05/25/93
int GtiGetLineField ( TableViewPtr pTableView,
                      VIEWFIELDNAME szFieldName,
                      VIEWLINENUM iLineNum,
                      VIEWFIELDVALUE szFieldValue,
                      ErrBlockPtr sourceeb )
   int iRc ;      /* return code */
   ELOG_INIT( sourceeb,
              "GtiGetLineField",
              "retrieving the value of a line field in a table view" ) ;
   /* in Gti, we start numbering lines from 1, because that is the way a user
      sees them on the screen. In Ldm, following C conventions, we start
      numbering lines at 0. So in LdmSetField, we subtract 1 from iLineNum */
   iRc = LdmGetField( pTableView->pTran,
                      szFieldName,
                      szFieldValue,
                      iLineNum - 1,
                      0,                  /* map occurrence = 1 */
                      ELOG_ERRBLOCK ) ;
   /* in case Ldm returned a warning, indicate so to the calling function */
   iRc = ( iRc == LDM_RETURNOK ) ? RCT_RETURNOK : RCT_WARNCORECONNECT ;
   return( iRc ) ;
   /* if exception was raised, it was due to COREConnect */
   ELOG_END( RCT_FAILCORECONNECT ) ;
}which calls
/****************************** API Header *********************************\
* API Name: LdmGetField
* This function copies the string value of a specified FIELDNAME into a
* buffer specified by FIELDVALUE. The string is NULL terminated.
* The first OCCUR determines which occurrence of the field in the map.
* The second OCCUR determines which occurence of the map in the transaction
* area. Remember that occurrences are numbered like C arrays: a transaction
* with ten occurrences of a field will have fields numbered zero through
* nine.
* It is assumed that FIELDVALUE has enough space to accommodate the field's
* value.
int LdmGetField( HTRAN       htran,
                 FIELDNAME   fieldname,
                 FIELDVALUE fieldvalue,
                 FIELDOCCUR fieldoccur,
                 MAPOCCUR    mapoccur,
                 ErrBlockPtr seb )
   ELOG_INIT ( seb, "LdmGetField", "getting transaction field value" ) ;
   if ( htran->Occurrence <= mapoccur ) {
      ElogFail1( LDM_FAILOCCNOTFOUND, htran->TranName ) ;
   } /* END if. */
   /* Since 'blank' values for field or map occurrences are zero, there
      is no need to set a default. */
   LdmsGetField( htran->Map->CCMap,
                 htran->TranData,
                 fieldname,
                 fieldvalue,
                 fieldoccur,
                 mapoccur,
                 ELOG_ERRBLOCK ) ;
   return( LDM_RETURNOK ) ;
   ELOG_END ( ELOG_ERRBLOCK->Rc ) ;
} /* END LdmGetField. */which calls
/****************************** API Header *********************************\
* API Name: LdmsGetField
* Put the value of FIELDNAME into FIELDVALUE. The field must be an element
* of the specified map. The new value will be set in the specified data
* buffer. The occurrences refer to the occurrence of the field in the map
* and the occurrence of the map in the data buffer.
int LdmsGetField ( CCMapPtr    rcmap,
                   char        *dataarea,
                   FIELDNAME   fieldname,
                   FIELDVALUE fieldvalue,
                   FIELDOCCUR fieldoccur,
                   MAPOCCUR    mapoccur,
                   ErrBlockPtr seb )
   ElementPtr element ;
   char       *fieldoffset ;
   ELOG_INIT ( seb, "LdmsGetField", "getting a field of a map" ) ;
   /* Search the transaction definition area (map) for matching
      FIELDNAME. If found, copy FIELDVALUE to defined offset in
      transaction buffer. */
   element = LdmsFindField( rcmap, fieldname, fieldoccur, &localeb ) ;
   /* Copy the value from the transaction data area into FIELDVALUE. */
   fieldoffset = dataarea +
                 ( ( rcmap->BufferLength * mapoccur ) + element->Offset ) ;
   strncpy( fieldvalue, fieldoffset, element->Length ) ;
   fieldvalue[ element->Length ] = '\0' ;
   return( LDM_RETURNOK ) ;
   ELOG_END ( ELOG_ERRBLOCK->Rc ) ;
} /* END LdmsGetField. */and on it goes
I gather from your question about arrays that they might be the source of the problem. Could it be that the pointer to the array is returned while the array is not completed? Any information would help. Thanks.

Select_list_from_lov, cant get the returning value

Hi
I try to use a apex_item.select_list_from_lov in a wizard. The LOV that I have is a dynamic list.
everything works fine, only I cant get the return value of the selected items.
multi select list
htp.p(apex_item.SELECT_LIST_FROM_LOV
( 2,
'MOS_ROL_OMSCHRIJVING',
' MULTIPLE HEIGHT=5',
'NO',
null,
null,
null,
null,
'NO')
trying to see what the return values are, but got nothing.
:p12_test := :f02;
(p12_test is a textfield)
any assistance would be greatly appreciated.
Thanks
using apex 4.0.

>
trying to see what the return values are, but got nothing.
:p12_test := :f02;
(p12_test is a textfield)
>
f02 is an associative array. See Referencing Arrays in the APEX API Reference for information on how to access values of items created using apex_item methods.

Reading return values in ArrayBinding situation

Hi All.
I'm currently using ArrayBinding to batch insert/update records into a table. I currently have an InOut parameter set that will either set or return the ID of the row depending if it's an INSERT or UPDATE.
What I'm struggling to do is to actually read the values that come back after ExecuteNonQuery. here is some excerpts of the code:
OracleParameter requirementId = new OracleParameter("p_id", OracleDbType.Int32, ParameterDirection.InputOutput);
               requirementId.ArrayBindStatus = new OracleParameterStatus[reqDS.MyRequirements.Count];
<set up the other params>
<set up the values in a loop>
requirementCmd.CommandText          = "PCM_PKG_REQUIREMENT_DAC.USP_SAVE_REQUIREMENT";
                    requirementCmd.ArrayBindCount     = reqDS.MyRequirements.Count;
requirementCmd.ExecuteNonQuery();
Now what? I've tried all sorts of ways to get to this but to no avail. My code to get it currently looks like this:
for (int j = 0; requirementId.ArrayBindStatus.Length - 1;j++)
                         //value = CType(outParameter.Value, Object)(i);
                         requirementToReqVersion.Add(reqDS.MyRequirements.RequirementId,requirementId[j].Value);
This doesnt even compile but you can see what I'm getting at. I just need to retrieve a value given an index in the array bind? Thanks for the help in advance..
jk

In VB.NET, we do something like this:
Option Explicit On
Option Strict On
Dim values() As Object
ReDim values(versions.Length - 1)     ' expected nbr of returned values
ReDim identities(versions.Length - 1)
Dim outParameter As OracleParameter
outParameter = command.Parameters("NameOfOutParameter")
CDbLateBinding.GetObjectArrayFromOutParameter(outParameter, values)
Dim i As Integer
For i = 0 To values.Length - 1
identities(i) = CType(CType(values(i), OracleDecimal).ToString, Decimal)
Next
' Separate file
Option Strict Off
Public Class CDbLateBinding
Public Shared Sub GetObjectArrayFromOutParameter(ByVal parameter As OracleParameter, _
ByVal values() As Object)
Dim i As Integer
For i = 0 To parameter.ArrayBindStatus.Length - 1
values(i) = CType(parameter.Value, Object)(i) ' Option Strict Off
Next
End Sub
End Class
Looks a bit awkward but works fine.
Armin

Return value gets lost

Hi,
I have one or more UnicastRemoteObject X with a method returning a byte-array. For every X there is a Thread Y with communicates with X over the X_RemoteInterface. In about 49 of 50 cases the method works fine, but sometimes it just doesn't return and the Thread freezes. What could my problem be? I'm very confused.
Sample code
public class X extends UnicastRemoteObject implements X_RemoteInterface {
public byte [] getBytes() {
byte [] b = .... <-- executes correctly
return b; <-- doesn't always reach the Object that called 'getBytes()'
public class Y extends Thread {
X_RemoteInterface xInterface;
public void run() {
xInterface.getBytes(); <-- sometimes Method doesn't return and Thread freezes

thanks wbracken for reading and understanding this :-)
the getBytes() method is not finishing up. It executes everything until the RETURN command (I checked this with lots of System.out.printlns), but the return value doesn't seem to reach the calling Thread ==> it just doesn't recieve any return parameter, so it continues waiting forever.
actually the whole method is synchronized. What kind of deadlock shoud I be looking for? the thing is, the method executes fine until the return statement and there is only one Thread for one X-Class with the getBytes() method.
So far I have used similar methods in other projects, but this time the amount of UnicastRemoteObjects is much higher. Could that cause the RMI not to work 100& correct anymore?

Inferring return value assignment types - ever seen this ?

Consider a class designed to hold arbitrary values defined at runtime. It is backed by a Map<String,Object> and values are stored and retrieved by a String identifier. Basic type checking is also performed.
Setting the values is straightforward: obj.set(name, value) but I have two candidates for syntax of getters.
First an example of the obvious approach, where getInteger(…) performs type checking, casting and explicitly returns an Integer:
Integer id = obj.getInteger("id") ;This is ok but I discovered a more consice syntax that works without without explicitly naming a type nor sacrificing type safety any further:
Integer id = obj.get("id") ;In this approach we use a generic method, where the return type is inferred and passed to the method. Here's how I do it:
// root method that is called by both approaches
private <K> K _get(String name, Class<K> clz) {
Object value = map.get(name) ;
// check for null, assignability, etc.
if (!clz.isAssignableFrom(value.getClass())) {
throw new RuntimeException(clz + " is not assignable from " + value.getClass()) ;
return (K) value ;
// method 1 - the obvious way
public Integer getInteger(String name) {
return _get(name, Integer.class) ;
// method 2
public <T> T get(String name, T...ts) {
if (ts.length > 0) throw new RuntimeException("Illegal usage...") ;
return (T) _get(name, ts.getClass().getComponentType()) ;
}This works becaues type T is used for both the var-arg array and the return value. Of course, it probably fails if you provide additional args - you're not supposed to. ts.getClass().getComponentType() returns the type you are assigning the return value to.
Not many languages can take this into consideration. In a way, it makes the return type part of the signature.
Advantages:
- Much smaller API
- Dynamic extension for use with a new datatype doesn't require adding a new getX() method
- Members can be treated uniformly, such a through iteration
Disadvantages:
- Involve the confusing zero-length var-args in the api that must be ignored
- Type is inferred to be Object when the return value is not assigned
At first you might think that the method 1 is more type-safe but in fact it is not. Using method 1 you have to align the method with the assignment type, but you can still exception at runtime. In method2 the datatype is simply inferred.
I'm interested in your thoughts on this teqnique. Please let me know if you have a way of concealing the var-args oddness. I think this technique could complement various patterns quite well, such as factory.
Thanks for your input.
Edited by: crackleOK on Jul 21, 2009 4:46 AM

crackleOK wrote:
JoachimSauer wrote:
The only redeeming quality is that it can be very nice to use such code.API's are to use (and often have ugly guts). Unfortunately true, but not a good reason to write ugly implementation code. If you only care about code quality up to the API, then you only care about the shiny coating of your car as well and don't mind the rust as long as you don't see it.
As I said: sometimes the tradeoff is worth it, but it should still be weighted.
Also: the ignorable varargs parameters are not needed in any way whatsoever.Please explain.From what I see you can replace this method:
public <T> T get(String name, T...ts)
// with
public <T> T get(String name)without any loss of functionality.

Windows 10 Caps Lock and Num Lock dosen`t work

Hi guys,
I have a problem to report, on asus k52de dosen`t work Light from the Caps and num lock .
This problem appered yesterday when windows make the last update.
If anybody is in the same problem like me please answer the solution.
THX

I've developed registry settings that both enable the "Filter Keys" feature in the Ease of Access center and use other values for which there are not UI fields to set repeat values to slow things down, but use values a little different
than those provided by the UI.
With this registry file the start of auto-repeat is slowed to 440 milliseconds, and the keys repeat at a reasonable rate of something around 30 per second.
http://Noel.ProDigitalSoftware.com/ForumPosts/Win10/Win10FastKeyboardRepeatFix.reg
Here's what's inside the above:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response]
"Last Valid Wait"=dword:00000000
"Last Valid Delay"=dword:000003e8
"Last Valid Repeat"=dword:000001f4
"Last BounceKey Setting"=dword:00000000
"Flags"="59"
"DelayBeforeAcceptance"="0"
"AutoRepeatRate"="20"
"AutoRepeatDelay"="440"
"BounceTime"="0"
The following registry file disables "Filter Keys" and returns Windows to the default settings. If you employ the above, after the next build drop I suggest running the following and see if Microsoft has fixed the problem (they've acknowledged
it and said it will be fixed in a future build).
http://Noel.ProDigitalSoftware.com/ForumPosts/Win10/Win10KeyboardRepeatReturnToDefault.reg
The above contains:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response]
"Last Valid Wait"=dword:00000000
"Last Valid Delay"=dword:000003e8
"Last Valid Repeat"=dword:000001f4
"Last BounceKey Setting"=dword:00000000
"Flags"="58"
"DelayBeforeAcceptance"="0"
"AutoRepeatRate"="500"
"AutoRepeatDelay"="1000"
"BounceTime"="0"
If you're at all skeptical about running downloaded .reg files from other folks (as you should be), I encourage you to use the text yourself or download them and look inside with an editor before running them.
-Noel
Detailed how-to in my eBooks:
Configure The Windows 7 "To Work" Options
Configure The Windows 8 "To Work" Options

Unable to capture return values in web services api

At the time of login to web services if my server is down ,
it returns following error :
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(String.java:1438)
        at java.lang.String.substring(String.java:1411)
I want to capture this error so that i can try another server to login. how do i capture this error
Another place where i want to capture the return Value is when i look for a report on the server
rh = boBIPlatform.get("path://InfoObjects/Root Folder/"src_folder"/" + reportName +
                           "@SI_SCHEDULEINFO,SI_PROCESSINFO" ,oGetOptions);
oInfoObjects = rh.getInfoObjects();
CrystalReport = (CrystalReport)oInfoObjects.getInfoObject(0);
Here if the report is not there on the server , it returns a null handler exception.
but if i try catching it by checking my responsehandler is null like rh == null it does not catch it.
Any help will be appreciated
thanks
Rakesh Gupta

Ted : i have two cases
1)   server = server_st.nextToken();
    providerURL = "http://"server"/dswsbobje/services";
    sessConnURL = new URL(providerURL + "/session");
   Connection boConnection = new Connection(sessConnURL);
   Session boSession = new Session(boConnection);
EnterpriseCredential boEnterpriseCredential = new    EnterpriseCredential();
              boEnterpriseCredential.setLogin(userid);
boEnterpriseCredential.setPassword(pwd);
boEnterpriseCredential.setAuthType(auth);
SessionInfo boSI = boSession.login(boEnterpriseCredential);
I have got a list of servers running web servcies stored in my tokens. when i pass the first server name say " test:8080" and that server is down , i want to catch somewhere in the code above that it did not get the connection so that i can loop back and try with the second server say test1:8080
This is for failover purposes.
at present when i was trying to capture return value of boSI it breaks giving the error
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1438)
at java.lang.String.substring(String.java:1411)
2nd case :
I am geeting reports from the server and scheduling them:
i run the following code which works fine if reports is there
rh = boBIPlatform.get("path://InfoObjects/Root Folder/"src_folder"/" + reportName +
"@SI_SCHEDULEINFO,SI_PROCESSINFO" ,oGetOptions);
oInfoObjects = rh.getInfoObjects();
CrystalReport = (CrystalReport)oInfoObjects.getInfoObject(0);
Here if the report is not there on the server then i should be able to catch from the response handle rh that it has got a null value.
but rh does not return a null value
the code ultimately throws a null handle at the following line
CrystalReport = (CrystalReport)oInfoObjects.getInfoObject(0);
i am not able to catch the null value there also.
hope you got my issue.

Multiple return values (Bug-ID 4222792)

I had exactly the same request for the same 3 reasons: strong type safety and code correctness verification at compile-time, code readability and ease of mantenance, performance.
Here is what Sun replied to me:
Autoboxing and varargs are provided as part of
JSRs 14 and 201
http://jcp.org/en/jsr/detail?id=14
http://jcp.org/en/jsr/detail?id=201
See also:
http://forum.java.sun.com/forum.jsp?forum=316
http://developer.java.sun.com/developer/earlyAccess/adding_generics/index.html
Multiple return values is covered by Bug-ID 4222792
Typically this is done by returning an array.
http://developer.java.sun.com/developer/bugParade/bugs/4222792.html
That's exactly the problem: we dynamically create instances of array objects that would better fit well within the operand stack without stressing the garbage collector with temporary Array object instances (and with their backing store: 2 separate allocations that need to be recycled when it is clearly a pollution that the operand stack would clean up more efficiently)
If you would like to engage in a discussion with the Java Language developers, the Generics forum would be a better place:
http://forum.java.sun.com/forum.jsp?forum=316
I know that (my report was already refering to the JSR for language extension) Generics is not what I was refering to (even if a generic could handle multiple return values, it would still be an allocated Object
instance to pack them, i.e. just less convenient than using a static class for type safety.
The most common case of multiple return values involve values that have known static datatypes and that should be checked with strong typesafety.
The simple case that involves returning two ints then will require at least two object instances and will not solve the garbage collection overhead.
Using a array of variable objects is exactly similar, except that it requires two instances for the components and one instance for the generic array container. Using extra method parameters with Integer, Byte, ... boxing objects is more efficient, but for now the only practical solution (which causes the least pollution in the VM allocator and garbage collector) is to use a custom class to store the return values in a single instance.
This is not natural, and needlessly complexifies many interfaces.
So to avoid this pollution, some solutions are used such as packing two ints into a long and returning a long, depacking the long after return (not quite clean but still much faster at run-time for methods that need to be used with high frequencies within the application. In some case, the only way to cut down the overhead is to inline methods within the caller code, and this does not help code maintenance by splitting the implementation into small methods (something that C++ can do very easily, both because it supports native types parameters by reference, and because it also supports inline methods).
Finally, suppose we don't want to use tricky code, difficult to maintain, then we'll have to use boxing Object types to allow passing arguments by reference. Shamely boxed native types cannot be allocated on the operand stack as local variables, so we need to instanciate these local variables before call, and we loose the capacity to track the cases where these local variables are not really initialized by an effective call to the method that will assign them. This does not help debugging, and is against the concept of a strongly typed language like Java should be:
Java makes lots of efforts to track uninitialized variables, but has no way to determine if an already instanciated Object instance refered in a local variable has effectively received an effective assignment because only the instanciation is kept. A typical code will then need to be written like this:
Integer a = null;
Integer b = null;
if (some condition) {
//call.method(a, b, 0, 1, "dummy input arg");
// the method is supposed to have assigned a value to a and b,
// but can't if a and b have not been instanciated, so we perform:
call.method(a = new Integer(), b = new Integer(), 0, 1, "dummy input
arg");
// we must suppose that the method has modified (not initialized!)
the value
// of a and b instances.
now.use(a.value(), b.value())
// are we sure here that a and b have received a value????
// the code may be detected at run-time (a null exception)
// or completely undetected (the method() above was called but it
// forgot to assign a value to its referenced objects a and b, in which
// case we are calling in fact: now.use(0, 0); with the default values
// or a and b, assigned when they were instanciated)
Very tricky... Hard to debug. It would be much simpler if we just used:
int a;
int b;
if (some condition) {
(a, b) = call.method(0, 1, "dummy input arg");
now.use(a, b);
The compiler would immediately detect the case where a and b are in fact not always initialized (possible use bere initialization), and the first invoked call.method() would not have to check if its arguments are not null, it would not compile if it forgets to return two values in some code path...
There's no need to provide extra boxing objects in the source as well as at run-time, and there's no stress added to the VM allocator or garbage collector simply because return values are only allocated on the perand stack by the caller, directly instanciated within the callee which MUST (checked at compile-time) create such instances by using the return statement to instanciate them, and the caller now just needs to use directly the variables which were referenced before call (here a and b). Clean and mean. And it allows strong typechecking as well (so this is a real help for programmers.
Note that the signature of the method() above is:
class call {
(int, int) method(int, int, String) { ... }
id est:
class "call", member name "method", member type "(IILjava.lang.string;)II"
This last signature means that the method can only be called by returning the value into a pair of variables of type int, or using the return value as a pair of actual arguments for another method call such as:
call.method(call.method("dummy input arg"), "other dummy input arg")
This is strongly typed and convenient to write and debug and very efficient at run-time...

Can anyone give me some real-world examples where
multiple return values aren't better captured in a
class that logically groups those values? I can of
course give hundreds of examples for why it's better
to capture method arguments as multiple values instead
of as one "logical object", but whenever I've hankered
for multiple return values, I end up rethinking my
strategy and rewriting my code to be better Object
Oriented.I'd personally say you're usually right. There's almost always a O-O way of avoiding the situation.
Sometimes though, you really do just want to return "two ints" from a function. There's no logical object you can think of to put them in. So you end up polluting the namespace:
public class MyUsefulClass {
public TwoInts calculateSomething(int a, int b, int c) {
public static class TwoInts {
    //now, do I use two public int fields here, making it
    //in essence a struct?
   //or do I make my two ints private & final, which
   //requires a constructor & two getters?
//and while I'm at it, is it worth implementing
//equals(), how about hashCode()? clone()?
//readResolve() ?
}The answer to most of the questions for something as simple as "TwoInts" is usually "no: its not worth implementing those methods", but I still have to think about them.
More to the point, the TwoInts class looks so ugly polluting the top level namespace like that, MyUsefulClass.TwoInts is public, that I don't think I've ever actually created that class. I always find some way to avoid it, even if the workaround is just as ugly.
For myself, I'd like to see some simple pass-by-value "Tuple" type. My fear is it'd be abused as a way for lazy programmers to avoid creating objects when they should have a logical type for readability & maintainability.
Anyone who has maintained code where someone has passed in all their arguments as (mutable!) Maps, Collections and/or Arrays and "returned" values by mutating those structures knows what a nightmare it can be. Which I suppose is an argument that cuts both ways: on the one hand you can say: "why add Tuples which would be another easy thing to abuse", on the other: "why not add Tuples, given Arrays and the Collections framework already allow bad programmers to produce unmainable mush. One more feature isn't going to make a difference either way".
Ho hum.

Unable to see function return values in Visual Studio 2013 debugger

Hi!
I can't see function return values in
Microsoft Visual Studio Ultimate 2013
Version 12.0.31101.00 Update 4
Microsoft .NET Framework
Version 4.5.51650
Installed Version: Ultimate<o:p></o:p>
as described in http://blogs.msdn.com/b/visualstudioalm/archive/2013/06/27/seeing-function-return-values-in-the-debugger-in-visual-studio-2013.aspx
So what can I do to get this functionality back?
MsdnMezzo

Hi MsdnMezzo,
Reference:
http://blogs.msdn.com/b/visualstudioalm/archive/2013/06/27/seeing-function-return-values-in-the-debugger-in-visual-studio-2013.aspx
If use the same sample in the above blog provided by you, how about the result? Could you debug it with the same steps? I could debug it in my side using the VS2013.
So to make sure that whether it is your VS IDE issue, please debug it with this sample, if it works well, I doubt that we would think about your specific project and the debugging steps.
If so, to really repro this issue, could you share us a sample with one drive? You could upload your project to one drive and share us the downloaded link in your new reply, I will download and repro this issue in my side.
Best Regards,
Jack
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Best way to use return values in a webservices

Hi all,
Scenario: We have three web services. What is the best way to do this acitivity or is it possible?
webservice1
webservice2
webservice3
Call invoke webservice1 & 2 (they need to their work do be done parallely and will return a value eg "string")and call webservices3 with input values as the returned value from webservice 1 & 2.
Thanks,
Shashi
Edited by: Shashi_sr on Sep 17, 2010 1:46 PM

Hi Shashi,
The way to achieve your desired functionality is as follows:
Create a flow activity, and within that flow activity, you will call web services (using an invoke activity) webservice1 and webservice2.
After the flow activity, you will then use another invoke activity to call the 3rd webservice using the output given by the first 2 webservices.

How to get return values from task flow in af:region ?

Hi!
I'm working with a taskFlow that is rendered inside a popup using the "popup inside a region pattern" (http://www.oracle.com/technology/products/adf/patterns/popupregionpattern.pdf), but now this taskFlow has an input parameter and a return value definition. So the question is how to get a value returned by this taskFlow thas is called inside a region?
Any suggestion?
Thanks in advance!

Hi,
write the value to a shared memory scope like session and read it in the regionNavigation listener. If you follow the paper you refer to then the listener determines of the viewId is null, this a return happens. It wuld then look in the memory scope for the return value.
Another option would be to use an object that you pass as an argument to the task flow you open in the popup. Then you change the object you passed in, which then makes the return information available in teh calling flow. The object you pass in would have to be in a shared scope too
Frank

Return values from a jpd to a jpf

I basically want to call a jpd from a page flow and then receive the results back from the jpd in my page flow. I have created a process control from the jpd and have included it in my page flow controller file using the following annotation.
* @common:control
private controls.leaveProcessPControl leaveControl ;
But since my jpd has a client response node for sending back the results (which corresponds to callback interface in the code), my page flow controller file is throwing an error saying that leaveControl implements a callback interface and page flow cannot receive asynchronous callbacks. Can anyone tell me how to resolve this.
I would also like to know if there are different approaches for returning values back to the jpf from a jpd.
Thanks,
RK

We are talking web interface here, so forget about Callbacks. I suggest that
you create Web Servicethat implements your proces or a control that calls
proces. Then Call that WS fro a controller, but in sync. way. Send a request
and then pull for response. This pull can be implemented as while loop in
Controler, with wait inside loop.
That wont work realy well if jour proces is long running, as controller will
block. In that case you will have to implement some kind of pulling in every
action method in your controller and react - fill data in internal variable
of controller for example.
I hope it helps, butt remember thin is not always the best.
"rohini k" <[email protected]> wrote in message
news:4042178.1101851602508.JavaMail.root@jserv5...
I basically want to call a jpd from a page flow and then receive the
results back from the jpd in my page flow. I have created a process control
from the jpd and have included in my page flow controller file using the
following annotation.
* @common:control
private controls.leaveProcessPControl leaveControl ;
But since my jpd has a client response node for sending back the results
(which corresponds to callback interface in the code), my page flow
controller file is throwing an error saying that leaveControl implements a
callback interface and page flow cannot receive asynchronous callbacks.
Can anyone tell me how to resolve this.
I would also like to know if there are different approaches for returning
values back to the jpf from a jpd.
Thanks,
RK

Array dosen't work as mutiple return value

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