Play with JCN (Java compute node ) 

As the name spell it is the mix behaiour of java and compute node

One of the most important question is why and when to use JCN in IIB ToolKit.

Ans.This question can be better understood in the way you have the requirement as the same work can be done with Compute node also than why JCN ....

----it provies the flexibility.

----you can use the java code free from applying mind in esql.

----Becouse java is inbuilt in toolkit you can use the java inbuilt method.

----Higher use when u use Collection (java.util) package i  will explain with example so that you can  know    the horizon of java is unlimited but with compute node you have the limited access.

------------------------------              let us having an interesting example using Collection (TreeSet)------------------------

Set<String> setSheetNames =  new TreeSet<String>();

String SheetName = null;

MbElement root = message.getRootElement();

java.util.List record = (java.util.List)root.evaluateXPath(new MbXPath("/db/sheets"));          // DFDL tree

int count  = record.size();

MbElement rec = root.getLastChild().getFirstChild().getFirstChild();

for(int i=1; i<= count; i++)//storing the unique sheet names into Set object

{

SheetName=SheetName.trim();

SheetName = rec.getFirstElementByPath("Spends").getValueAsString();

setSheetNames.add(SheetName);

rec = rec.getNextSibling();

}

 int countForSheets = setSheetNames.size();

 Iterator itr = setSheetNames.iterator();

 String newsheetname=null;

try{

while(itr.hasNext())          //Iterating unique sheet names and creating unique sheets by using Set object

 {

newsheetname = (String) itr.next();

sheetdb = (SXSSFSheet)workbook.createSheet(newsheetname);

Row rowheadSheet = sheetdb.createRow((int) 0);// rowhead1

     }

Are You really Feeling interesting than we should go some little inside ..........

Now it is the question Answer  phase Not theory but only code and practical :- 

All the ans will depends upon the tree u have :-

1.How to access DFDL element in JCN.

Ans:-    

                MbElement root = message.getRootElement();

                 java.util.List record = (java.util.List)root.evaluateXPath(new MbXPath("/db/sheets"));   // DFDL

                MbElement rec = root.getLastChild().getFirstChild().getFirstChild();//According to above Figure

                for(int i=1; i<= count; i++)                                          //For loop to access the element from the tree

                {

                String SheetName = rec.getFirstElementByPath("Spends").getValueAsString();

                //Do your required work ....................................

                rec = rec.getNextSibling();

                }

2.How to access Local Environment variables in JCN.

Ans:- String fname=(String)inAssembly.getLocalEnvironment().evaluateXPath("/File/Name");

3.How to access Environment variables in JCN.

Ans:-

String rate = inAssembly.getGlobalEnvironment().getRootElement().getFirstElementByPath("RatePerJPMile").getValue().toString();

4.How to Throw and catch the Exception.

Ans:-

1)

                try{

               

                //your work that may thorw some Exception

       

      }catch (Exception e)

       {

      throw new MbUserException(this,"evaluate()","","",e.toString(),null);

                             

      }

2) public void evaluate(MbMessageAssembly inAssembly) throws MbException....

3)You can use try and catch block.

Remember after passing from the JCN your Exception tree will be Affected.  

5.How to generate the EXCEL Sheet using JCN.

6.How to write and read from EXCEL Sheet in JCN.

Ans:- This is the Combine code for 5 and 6 for  Generating EXCEL sheet in JCN with complete code

package  abc.xyz import java.io.ByteArrayOutputStream; import java.text.DateFormatSymbols; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Iterator; import java.util.Set; import java.util.TreeSet; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.xssf.streaming.SXSSFSheet; import org.apache.poi.xssf.streaming.SXSSFWorkbook; import com.ibm.broker.javacompute.MbJavaComputeNode; import com.ibm.broker.plugin.MbBLOB; import com.ibm.broker.plugin.MbElement; import com.ibm.broker.plugin.MbException; import com.ibm.broker.plugin.MbMessage; import com.ibm.broker.plugin.MbMessageAssembly; import com.ibm.broker.plugin.MbOutputTerminal; import com.ibm.broker.plugin.MbUserException; import com.ibm.broker.plugin.MbXPath; public class ABC_JavaCompute extends MbJavaComputeNode {                 public void evaluate(MbMessageAssembly inAssembly) throws MbException {                 MbOutputTerminal out = getOutputTerminal("out");                 //String rate = inAssembly.getGlobalEnvironment().getRootElement().getFirstElementByPath("Rate").getValue().toString();                 MbMessage inMessage = inAssembly.getMessage();                 System.out.println(".................................................");                                 byte[] outdata = createFile(inMessage);                                 System.out.println(".........................................");                                 MbMessageAssembly outAssembly = null; try {                 MbMessage outMessage = new MbMessage();                 copyMessageHeaders(inMessage, outMessage);                 outAssembly = new MbMessageAssembly(inAssembly, outMessage);                                                 //String fname=(String)inAssembly.getLocalEnvironment().evaluateXPath("/File/Name"); // Sending the Output excel file data as a BLOB message MbElement outRoot = outMessage.getRootElement(); MbElement outParser = outRoot.createElementAsLastChild(MbBLOB.PARSER_NAME); outParser.createElementAsLastChild(MbElement.TYPE_NAME_VALUE, "BLOB", outdata); //getting the file name from Environment //String OutputFileName = inAssembly.getGlobalEnvironment().getRootElement().getFirstElementByPath("OutputFileName").getValue().toString(); //OutputFileName = OutputFileName.substring(0, OutputFileName.lastIndexOf('.')); // FilenameUtils.removeExtension(); //UPDATING LOCAL ENVIRONMENT with Directory values and the File Name MbElement outLocal= outAssembly.getGlobalEnvironment().getRootElement(); MbElement destination = outLocal.createElementAsLastChild(MbElement.TYPE_NAME,"OutFileName", null); SimpleDateFormat datef = new SimpleDateFormat("MM"); String monthName = datef.format(new Date()); int month = Integer.parseInt(monthName);  String outputFileName = getMonth(month); String monthNameChar = outputFileName.substring(0, 3).toUpperCase(); SimpleDateFormat year = new SimpleDateFormat("yy"); String yearName = year.format(new Date()); destination.createElementAsLastChild(MbElement.TYPE_NAME_VALUE,"OutputFileName","FileName"+monthNameChar+yearName+".xlsx"); } catch (MbException e) { // Re-throw to allow Broker handling of MbException                 throw e;                 } catch (RuntimeException e) {                 // Re-throw to allow Broker handling of RuntimeException                 throw e; } catch (Exception e) {                 throw new MbUserException(this, "evaluate()", "", "", e.toString(),null); } out.propagate(outAssembly);                                 System.out.println("exit from.................JCN");                 } public void copyMessageHeaders(MbMessage inMessage, MbMessage outMessage)                                 throws MbException { MbElement outRoot = outMessage.getRootElement(); MbElement header = inMessage.getRootElement().getFirstChild(); while (header != null && header.getNextSibling() != null) // stop before { outRoot.addAsLastChild(header.copy()); header = header.getNextSibling(); } } private String getMonth(int month)                 {                  return new DateFormatSymbols().getMonths()[month-1];                 } private byte[] createFile(MbMessage message) { byte[] output = null; try{ SXSSFWorkbook workbook = new SXSSFWorkbook(10000000);  SXSSFSheet  sheetdb = null; Set<String> setSheetNames =  new TreeSet<String>();  String SheetName = null; MbElement root1 = message.getRootElement();  java.util.List record1 = (java.util.List)root1.evaluateXPath(new MbXPath("/db/sheets"));   int count1  = record1.size(); MbElement rec1 = root1.getLastChild().getFirstChild().getFirstChild(); for(int i=1; i<= count1; i++)//storing the unique sheet names into Set object      { SheetName = rec1.getFirstElementByPath("Spends").getValueAsString(); SheetName=SheetName.trim(); setSheetNames.add(SheetName); rec1 = rec1.getNextSibling(); } int countForSheets = setSheetNames.size(); Iterator itr = setSheetNames.iterator(); String newsheetname=null; try{ while(itr.hasNext())//Iterating unique sheet names and creating unique sheets by using Set object { newsheetname = (String) itr.next(); sheetdb = (SXSSFSheet)workbook.createSheet(newsheetname); Row rowheadSheet = sheetdb.createRow((int) 0);// rowhead1 createRowHead(sheetdb, rowheadSheet); } }catch(Exception e){} root1=null; rec1=null; record1=null; MbElement root = message.getRootElement(); java.util.List record = (java.util.List)root.evaluateXPath(new MbXPath("/_Invoice/body")); int count  = record.size(); MbElement rec = root.getLastChild().getFirstChild().getNextSibling().getFirstChild(); //This is For sheet 1 SXSSFSheet  sheetdblast=null; for (int i = 0; i < count; i++) { String sheetNameUnique = rec.getFirstElementByPath("sheetNameUnique").getValueAsString(); sheetdblast = (SXSSFSheet) workbook.getSheet(sheetNameUnique); int rowNumber = sheetdblast.getLastRowNum(); Row row = sheetdblast.createRow((int)1+rowNumber); Row rowForHeader = sheetdblast.getRow(0); String JPPercentage=null; String JetPercentage=null; String PartnerPercentage=null; try{ JPPercentage =rec.getFirstElementByPath("JPPercentage").getValueAsString(); }catch(Exception e){}try{ JetPercentage=rec.getFirstElementByPath("JetPercentage").getValueAsString(); }catch(Exception e){}try{ PartnerPercentage =rec.getFirstElementByPath("PartnerPercentage").getValueAsString(); }catch(Exception e){}try{ rowForHeader.getCell(7).setCellValue("BilledMiles - JP "+"("+JPPercentage+"%)"); }catch(Exception e){}try{ rowForHeader.getCell(8).setCellValue("BilledMiles - 9W"+"("+JPPercentage+"%)"); }catch(Exception e){}try{ rowForHeader.getCell(9).setCellValue("BilledMiles - EBL"+"("+PartnerPercentage+"%)"); }catch(Exception e){} double RateFinal=0.0; double TotalMiles=0.0; double JPMiles=0.0; double PartnerMiles=0.0; double JetMiles=0.0; try{ String MemberNumber=rec.getFirstElementByPath("JpNumber").getValueAsString(); double MemberNumber123=Double.parseDouble(MemberNumber); row.createCell(0).setCellValue(MemberNumber123); }catch(Exception e){}try{ row.createCell(1).setCellValue(rec.getFirstElementByPath("Name").getValueAsString()); }catch(Exception e){}try{ row.createCell(2).setCellValue(rec.getFirstElementByPath("ActivityCode").getValueAsString()); }catch(Exception e){}try{ String Year=rec.getFirstElementByPath("Year").getValueAsString(); double Year123=Double.parseDouble(Year); row.createCell(3).setCellValue(Year123); }catch(Exception e){}try{ String Month=rec.getFirstElementByPath("Month").getValueAsString(); double Month123=Double.parseDouble(Month); row.createCell(4).setCellValue(Month123); }catch(Exception e){}try{ String Date=rec.getFirstElementByPath("Date").getValueAsString(); double Date123=Double.parseDouble(Date); row.createCell(5).setCellValue(Date123); }catch(Exception e){}try{ String  TotalMiles123=rec.getFirstElementByPath("TotalMiles").getValueAsString(); TotalMiles=Double.parseDouble(TotalMiles123); row.createCell(6).setCellValue(TotalMiles); }catch(Exception e){} try{ String JPPercentage123=rec.getFirstElementByPath("JPPercentage").getValueAsString(); double JPPercentageFinal=Double.parseDouble(JPPercentage123); JPMiles=TotalMiles*JPPercentageFinal/100;     row.createCell(7).setCellValue(JPMiles); }catch(Exception e){} try{ String JetPercentage123=rec.getFirstElementByPath("JetPercentage").getValueAsString(); double JetPercentageFinal=Double.parseDouble(JetPercentage123); JetMiles=TotalMiles*JetPercentageFinal/100; row.createCell(8).setCellValue(JetMiles); }catch(Exception e){} try{ String PartnerPercentage123=rec.getFirstElementByPath("PartnerPercentage").getValueAsString(); double PartnerPercentageFinal=Double.parseDouble(PartnerPercentage123); PartnerMiles=TotalMiles*PartnerPercentageFinal/100; row.createCell(9).setCellValue(PartnerMiles); }catch(Exception e){}     try{ String Rate=rec.getFirstElementByPath("Rate").getValueAsString(); RateFinal=Double.parseDouble(Rate); row.createCell(10).setCellValue(RateFinal); }catch(Exception e){}try{                  row.createCell(11).setCellValue(rec.getFirstElementByPath("TransactionDate").getValueAsString()); }catch(Exception e){}                                                                                                 try{ double AmountJP=JPMiles*RateFinal; row.createCell(12).setCellValue(AmountJP); }catch(Exception e){} try{ double AmountJET=JetMiles*RateFinal; row.createCell(13).setCellValue(AmountJET); }catch(Exception e){} try{ double AmountEBL=PartnerMiles*RateFinal; row.createCell(14).setCellValue(AmountEBL); }catch(Exception e){}                                 try{                                        row.createCell(15).setCellValue(rec.getFirstElementByPath("Description").getValueAsString()); }catch(Exception e){} rec = rec.getNextSibling();  } root =null; record = null; rec = null;                                      MbElement rootLast = message.getRootElement(); java.util.List recordLast = (java.util.List)rootLast.evaluateXPath(new MbXPath("/db/sheets")); int countsheet  = recordLast.size(); MbElement recLast = rootLast.getLastChild().getFirstChild().getFirstChild(); int countForSheets123 = setSheetNames.size(); Iterator itr123 = setSheetNames.iterator(); while(itr123.hasNext())//Iterating unique sheet names and creating unique sheets by using Set object { newsheetname = (String) itr123.next();   //for(int recordTotal=0;recordTotal<countsheet ;recordTotal++){ try{   Sheet worksheet =  workbook.getSheet(newsheetname);   int rowsCount = worksheet.getPhysicalNumberOfRows(); Cell cell1=null; // Row getRow = worksheet.createRow((int)rowsCount); Row getRow =null; double Totalmiles2=0; double Totalmiles1=0;   //worksheet.getLastRowNum() for (int x = 0; x<rowsCount; x++) {   try   { getRow = worksheet.getRow(x); String Totalmiles = getRow.getCell((int) 6).toString();   try   {   Totalmiles2=Double.valueOf(Totalmiles);   Totalmiles1+=Totalmiles2; }catch(Exception e){ System.out.println("String Contain Empty value or null"); } }catch(Exception e){} } //Calculating the Total of jetpriviledge miles double JPMiles1=0; double JPMiles2=0;                                                      for (int x = 0; x<rowsCount; x++) { try{ getRow = worksheet.getRow(x); String JPMiles= getRow.getCell((int) 7).toString(); try{                 JPMiles2=Double.valueOf(JPMiles); JPMiles1+=JPMiles2;                                                                                                                      }catch(Exception e){   System.out.println("String Contain Empty value or null"); } }catch(Exception e){} cell1 = getRow.createCell(12); cell1.setCellValue(AmountTotalJP1); cell1 = getRow.createCell(13); cell1.setCellValue(AmountTotalJET1); //int x=worksheet.getLastRowNum(); //getRow = worksheet.getRow(x); cell1 = getRow.createCell(14);    cell1.setCellValue(AmountTotalPartner1); }catch(Exception e){} }              ByteArrayOutputStream bOut = new ByteArrayOutputStream();                         workbook.write(bOut);                 output= bOut.toByteArray();                  } catch ( Exception ex ) {          System.out.println(ex);      } return output; } //This below code is for creating header in Excel Sheet rowheadSheet.createCell(12).setCellValue("Amount-asd  "); rowheadSheet.createCell(13).setCellValue("Amount-dfg  "); rowheadSheet.createCell(14).setCellValue("Amount - gfh "); rowheadSheet.createCell(15).setCellValue("Description   "); for(int colNum = 0; colNum<rowheadSheet.getLastCellNum();colNum++) { firstSheet.autoSizeColumn(colNum );

7.How to access the header in JCN.

Ans: - Please refer to the above code with ---------Green------------color

8.How to porcess the result to out terminal in JCN.

Ans:-  - Please refer to the above code with ---------Red------------color

9.Benefit of using JCN.

Ans:- IF u like java than U can understand that  whatever u can do with java u can implement in JCN .

10.Drawback of using JCN.

Ans:-  Understanding and accessing the element  in JCN is difficult  and if some where NULLPointer Exception Will come than that will be like a chunk of bone in your neck.........

This will continue....................................................