Code Generator Reference Pages

 

This appendix contains reference pages for the eLink Java Adapter for Mainframe WLS Edition COBOL code generator (EgenCobol). It describes the rules for writing the script file that controls the code generator.

 

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EgenCobol

The EgenCobol tool maps a COBOL copybook into a Java class.

Synopsis

Invoke the tool with the following command:

java bea.jam.egen.EgenCobol scriptfile

where:

java

is the name of the Java virtual machine executable in the Java Development Kit (JDK).

bea.jam.egen.EgenCobol

is the full class name of the EgenCobol tool.

scriptfile

is the script file that controls the EgenCobol tool. You must write this script file on an application-by-application basis. (See Listing A-1 for an example).

Listing A-1 Example of scriptfile.egen

---

### example script
#

view demo.CustomDataView from emprec.cpy

service demoService accepts CustomDataView returns CustomDataView

page demoPage "Demo Page"
{
    view demo.CustomDataView

    buttons
    {
    		"Try It" service(demoService) shows demoPage
    }
}

servlet demo.DemoServlet shows demoPage

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Script Syntax Reserved Words

The reserved words shown in Table A-1 must be used as specified in the Grammar section.

Note: A reserved word can be used as an identifier if it is enclosed in either single or double quotation marks (refer to General rules).

Table A-1 Reserved Words

accepts	buttons	client	ejb	from	group
is	method	class	page	reset	returns
server	service	servlet	shows	view

General rules

• The `#' character and all following characters on the same line are a comment. Use the `#' character to specify commented text.

• The character sequence "//" and all following characters on the same line are a comment. Use the "//" characters to specify commented text.

• The character sequence "/*" and all following characters until the occurrence of the sequence "*/" are a comment. Use the "/*" characters to specify commented text that extends beyond one line.

• White space (including newlines) is not significant. White space includes newlines, carriage returns, tabs, spaces, etc.

• Any sequence of letters, digits, underscores, or periods is a word.

• Any word that does not match a reserved word is an identifier.

• Any sequence of characters is treated as an identifier if it is enclosed in either single or double quotes. This allows the use of reserved words and sequences that contain spaces.

Grammar

The following grammar is described using a modified Backus-Naur Form (BNF) syntax, such as in many industry-standard software reference guides. It specifies a context-free grammar. Reserved words are shown in bold. Comments are in italics preceded by a dash (-).

script:

definition | script definition

definition:

viewdef | servicedef | servletdef | ejbdef | classdef | pagedef

viewdef:

view viewname from copybook

servicedef:

service servicename accepts fullViewname returns fullViewname

servletdef:

servlet classname shows pagename

ejbdef:

clientejb | serverejb

clientejb:

client ejb classname ejbregistration { clientmethods }

serverejb:

server ejb classname ejbregistration { servermethods }

classdef:

client class classname { clientmethods }

pagedef:

page pagename title { view viewname buttons { buttonlist } }

buttonlist:

buttondef | buttonlist buttondef

buttondef:

servicebutton | ejbbutton

clientmethodslist:

clientmethoddef | clientmethodlist clientmethoddef

clientmethoddef:

method methodname is servicename

servicebutton:

buttonname service ( servicename ) shows pagename

ejbbutton:

buttonname ejbmethod ( fullViewname ) returns fullViewname

viewname:

classname

fullViewname:

viewname | viewname [ codepage ]

copybook:

identifier

-An identifier that names a file containing a COBOL data definition.

servicename:

identifier

-An identifier that matches a resource definition in your jcrmgw.cfg file

pagename:

identifier

-An identifier that names a page definition.

codepage:

identifier

-The name of a codepage to be used for character translation to/from mainframe data formats. This must be a codepage supported by the JDK being used.

methodname:

identifier

-The name to be given to a generated Java method.

classname:

identifier

-An identifier that names a Java class, including any package name.

ejbregistration:

identifier

-The name that will be used to register the home interface for an EJB.

title:

identifier

-The title to be placed into the HTML generated for a page.

buttonname:

identifier

-A button name that will be used in the HTML generated for a page.

ejbmethod:

identifier

-An EJB classname and method specification that should look like this:

package.ejbclass.method

or

ejbclass.method

Results of Running the Code Generator

• Each view definition (described in the Programming Reference section of this guide) causes the specified COBOL copybook to be parsed and a Java source file for the specified DataView class to be generated in the current directory.

• Each servlet definition causes a Java source file to be generated in the current directory for the specified class.

• Each client class definition causes a Java source file to be generated in the current directory for the specified class.

• Each EJB definition causes the generation of three Java source files and a deployment descriptor text file into the current directory. The names of the generated files are listed in Table A-2.

  Table A-2 Generated Files for EJB Definitions

  Name of File	Purpose
  classnameHome.java	EJB Home Interface
  classnameBean.java	EJB Implementation class
  classname.java	EJB Remote Interface
  classnameDD.txt	EJB Deployment Descriptor