Changes to the Metadata Model (SAP Library - Components of SAP Communication Technology)

Changes to the Metadata Model

Use

Some changes have also been made with the new JCo API in the area of the metadata model.

Separating Metadata Types

The most important new feature is based on separating the data container classes for structures and tables. JCo structure und JCo table were previously assigned to a common parent class. In the new API, structure and table metadata is assigned to two different metadata type to avoid any confusion. As a result of this separation, each record and parameterList has a reference to its own metadata object.

Enhancement of Metadata Objects

With the new JCo API, metadata objects contains both Unicode and non-Unicode information. This helps to avoid any errors when configuring the Repository.

Note

It is of course still recommended that you exercise caution with the general configuration of the Repository. For example, you should be sure to avoid using the same name for different functions in different systems.

Reducing Metadata Objects in the Memory

Only one object is stored in the memory for a specific metadata layout, this object references the corresponding tables and structures. This reduces the memory consumption, particularly for nested tables.

Consequences

● A consequence of these changes is that specific metadata operations (for example, addinfo()) are no longer possible for record and list objects.

● Also, the ParameterList.appendValue() method no longer exists.

● However, it is still possible to create JCoFunction and its JcoParameterLists on the fly.

● Additionally, it is now possible to lock a metadata object after you have created it to avoid any unwanted changes.

Prerequisites

The following activities are only relevant if you want to use an application with hard-coded metadata or with metadata-relevant APIs.

Procedure

Perform the required changes in your code to adapt the metadata model.

Example

The following examples show the differences between JCo 2.x and 3.0 in three different areas:

○ Retrieving metadata when only the data container is available

○ Creating a parameterList on the fly.

○ Setting up hard-coded metadata

Retrieving Metadata

JCo 2.x

JCO.Function function = template.getFunction();

JCO.ParameterList exports=function.getExportParameterList();

for (int i=0; i<exports.getFieldCount(); i++)

System.out.println("Parameter: " + exports.getName(i) +

" length " + exports.getLength(i) +

" is " + (exports.isOptional(i)?"":"not ") + "optional");

JCO.ParameterList tables=function.getTableParameterList();

JCO.Table theTable = tables.getTable("THE_TABLE");

for (int i=0; i<theTable.getFieldCount(); i++)

System.out.println("Field: " + theTable.getName(i) +

" length " + theTable.getLength(i) +

" offset " + theTable.getOffset(i));

System.out.println("Table length: " + theTable.getTabLength());

JCo 3.0

JCoFunction function = template.getFunction();

JCoParameterList exports=function.getExportParameterList();

JCoListMetaData listMetaData=exports.getListMetaData();

for (int i=0; i< listMetaData.getFieldCount(); i++)

System.out.println("Parameter: " + listMetaData.getName(i) +

" length " + listMetaData.getByteLength(i) +

" is " + (listMetaData.isOptional(i)?"":"not ") + "optional");

JCoParameterList tables=function.getTableParameterList();

JCoTable theTable = tables.getTable("THE_TABLE");

JCoRecordMetaData recordMetaData = theTable.getRecordMetaData();

for (int i=0; i< recordMetaData.getFieldCount(); i++)

System.out.println("Field: " + recordMetaData.getName(i) +

" length " + recordMetaData.getByteLength(i) +

" offset " + recordMetaData.getByteOffset(i));

System.out.println("Table length: " + recordMetaData.getRecordLength());

ParameterList on the fly

JCo 2.x

JCO.ParameterList imports = new JCO.ParameterList();

//no exports, tables and exceptions for this function

JCO.Function function = new JCO.Function("JCO_HELLO_WORLD", imports, null, null);

imports.appendValue("PARAM", JCO.TYPE_CHAR, 30, "Hello World!");

JCo 3.0

JCoListMetaData importsMeta = JCo.createParameterList();

importsMeta.add("PARAM", JCoMetaData.TYPE_CHAR, 30, 60, 0, null, null, 0, null, null);

importsMeta.lock();

//no exports, changings, tables and exceptions for this function

JCoFunction function = JCo.createFunctionTemplate("JCO_HELLO_WORLD", imports, null,

null, null, null).getFunction();

JCoParameterList imports = function.getImportParameterList();

imports.setValue("PARAM", "Hello World!");

Hard-Coded Metadata

JCo 2.x

JCO.MetaData bapiReturnUC = new JCO.MetaData("BAPIRETURN", 9);

JCO.MetaData bapiReturn = new JCO.MetaData("BAPIRETURN", 9);

JCO.MetaData companyListUC = new JCO.MetaData("BAPI0014_1", 2);

JCO.MetaData companyList = new JCO.MetaData("BAPI0014_1", 2);

bapiReturnUC.addInfo("TYPE", IMetaData.TYPE_CHAR, 1, 2, 0, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("CODE", IMetaData.TYPE_CHAR, 5, 10, 2, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("MESSAGE", IMetaData.TYPE_CHAR, 220, 440, 12, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("LOG_NO", IMetaData.TYPE_NUM, 20, 40, 452, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("LOG_MSG_NO", IMetaData.TYPE_CHAR, 6, 12, 492, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("MESSAGE_V1", IMetaData.TYPE_CHAR, 50, 100, 504, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("MESSAGE_V2", IMetaData.TYPE_CHAR, 50, 100, 604, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("MESSAGE_V3", IMetaData.TYPE_CHAR, 50, 100, 704, 0, null, null, 0,

null, null);

bapiReturnUC.addInfo("MESSAGE_V4", IMetaData.TYPE_CHAR, 50, 100, 804, 0, null, null, 0,

null, null);

bapiReturnUC.setTabLength(904);

bapiReturn.addInfo("TYPE", IMetaData.TYPE_CHAR, 1, 1, 0, 0, null, null, 0,

null, null);

bapiReturn.addInfo("CODE", IMetaData.TYPE_CHAR, 5, 5, 1, 0, null, null, 0,

null, null);

bapiReturn.addInfo("MESSAGE", IMetaData.TYPE_CHAR, 220, 220, 6, 0, null, null, 0,

null, null);

bapiReturn.addInfo("LOG_NO", IMetaData.TYPE_NUM, 20, 20, 226, 0, null, null, 0,

null, null);

bapiReturn.addInfo("LOG_MSG_NO", IMetaData.TYPE_CHAR, 6, 6, 246, 0, null, null, 0,

null, null);

bapiReturn.addInfo("MESSAGE_V1", IMetaData.TYPE_CHAR, 50, 50, 252, 0, null, null, 0,

null, null);

bapiReturn.addInfo("MESSAGE_V2", IMetaData.TYPE_CHAR, 50, 50, 302, 0, null, null, 0,

null, null);

bapiReturn.addInfo("MESSAGE_V3", IMetaData.TYPE_CHAR, 50, 50, 352, 0, null, null, 0,

null, null);

bapiReturn.addInfo("MESSAGE_V4", IMetaData.TYPE_CHAR, 50, 50, 402, 0, null, null, 0,

null, null);

bapiReturn.setTabLength(452);

companyListUC.addInfo("COMPANY", IMetaData.TYPE_CHAR, 6, 12, 0, 0, null, null, 0,

null, null);

companyListUC.addInfo("NAME1", IMetaData.TYPE_CHAR, 30, 60, 12, 0, null, null, 0,

null, null);

companyListUC.setTabLength(72);

companyList.addInfo("COMPANY", IMetaData.TYPE_CHAR, 6, 6, 0, 0, null, null, 0, null,

null);

companyList.addInfo("NAME1", IMetaData.TYPE_CHAR, 30, 30, 6, 0, null, null, 0, null,

null);

companyList.setTabLength(36);

JCO.MetaData exportsMetaUC=new JCO.MetaData("EXPORTS", 1);

exportsMetaUC.addInfo("RETURN", IMetaData.TYPE_STRUCTURE, 452, 904, 0, 0, null, null, 0,

bapiReturnUC, null);

JCO.MetaData exportsMeta=new JCO.MetaData("EXPORTS", 1);

exportsMeta.addInfo("RETURN", IMetaData.TYPE_STRUCTURE, 452, 452, 0, 0, null, null, 0,

bapiReturn, null);

JCO.MetaData tablesMetaUC=new JCO.MetaData("TABLES", 1);

tablesMetaUC.addInfo("COMPANY_LIST", IMetaData.TYPE_TABLE, 36, 72, 0, 0, null, null, 0,

companyListUC, null);

JCO.MetaData tablesMeta=new JCO.MetaData("TABLES", 1);

tablesMeta.addInfo("COMPANY_LIST", IMetaData.TYPE_TABLE, 36, 36, 0, 0, null, null, 0,

companyList, null);

JCO.Client client = JCO.getClient("FOO");

try

{

client.connect();

boolean isUnicode = client.getAttributes().getPartnerBytesPerChar()==2;

JCO.Function bapiCompanyGetList=null;

if (isUnicode)

bapiCompanyGetList=JCO.createFunction("BAPI_COMPANY_GETLIST", null,

JCO.createParameterList(exportsMetaUC),

JCO.createParameterList(tablesMetaUC));

else

bapiCompanyGetList=JCO.createFunction("BAPI_COMPANY_GETLIST", null,

JCO.createParameterList(exportsMeta),

JCO.createParameterList(tablesMeta));

client.execute(bapiCompanyGetList);

JCO.ParameterList tables= bapiCompanyGetList.getTableParameterList();

JCO.Table companies=tables.getTable("COMPANY_LIST");

for (int i=0; i<companies.getNumRows(); i++)

{

companies.setRow(i);

System.out.println(companies.getString("COMPANY")+

": "+companies.getString("NAME1"));

}

catch(Exception e)

{

System.err.println("Exception occured: "+e.toString());

}

finally

{

JCO.releaseClient(client);

}

JCo 3.0

JCoRecordMetaData bapiReturn = JCo.createRecordMetaData("BAPIRETURN", 9);

JCoRecordMetaData companyList = JCo.createRecordMetaData("BAPI0014_1", 2);

bapiReturn.add("TYPE", JCoMetaData.TYPE_CHAR, 1, 0, 2, 0, 0, null, null,

null);

bapiReturn.add("CODE", JCoMetaData.TYPE_CHAR, 5, 1, 10, 2, 0, null, null,

null);

bapiReturn.add("MESSAGE", JCoMetaData.TYPE_CHAR, 220, 6, 440, 12, 0, null, null,

null);

bapiReturn.add("LOG_NO", JCoMetaData.TYPE_NUM, 20, 226, 40, 452, 0, null, null,

null);

bapiReturn.add("LOG_MSG_NO", JCoMetaData.TYPE_CHAR, 6, 246, 12, 492, 0, null, null,

null);

bapiReturn.add("MESSAGE_V1", JCoMetaData.TYPE_CHAR, 50, 252, 100, 504, 0, null, null,

null);

bapiReturn.add("MESSAGE_V2", JCoMetaData.TYPE_CHAR, 50, 302, 100, 604, 0, null, null,

null);

bapiReturn.add("MESSAGE_V3", JCoMetaData.TYPE_CHAR, 50, 352, 100, 704, 0, null, null,

null);

bapiReturn.add("MESSAGE_V4", JCoMetaData.TYPE_CHAR, 50, 402, 100, 804, 0, null, null,

null);

bapiReturn.setRecordLength(452, 904);

bapiReturn.lock();

companyList.add("COMPANY", IMetaData.TYPE_CHAR, 6, 0, 12, 0, 0, null, null, 0, null,

null);

companyList.add("NAME1", IMetaData.TYPE_CHAR, 30, 6, 60, 12, 0, null, null, 0, null,

null);

companyList.setRecordLength(36, 72);

companyList.lock();

JCoListMetaData exportsMeta=JCo.createListMetaData("EXPORTS", 1);

exportsMeta.add("RETURN", JCoMetaData.TYPE_STRUCTURE, 452, 904, 0, null, null, 0,

bapiReturn, null);

JCoListMetaData tablesMeta=JCo.createListMetaData("TABLES", 1);

tablesMeta.add("COMPANY_LIST", JCoMetaData.TYPE_TABLE, 36, 72, 0, null, null, 0,

companyList, null);

JCoFunctionTemplate bapiCompanyGetListTemplate=JCo.createFunctionTemplate("BAPI_COMPANY_GETLIST",

null, exportsMeta, null, tablesMeta, null);

try

{

JCoDestination foo=JCoDestinationManager.getDestination("FOO");

JCO.Function bapiCompanyGetList=bapiCompanyGetListTemplate.getFunction();

bapiCompanyGetList.execute(foo);

JCoParameterList tables= bapiCompanyGetList.getTableParameterList();

JCoTable companies=tables.getTable("COMPANY_LIST");

for (int i=0; i<companies.getNumRows(); i++)

{

conmpanies.setRow(i)

System.out.println(companies.getString("COMPANY")+

": "+companies.getString("NAME1"));

}

catch(Exception e)

{

System.err.println("Exception occured: "+e.toString());

}