Error getting schema root with OLAP API

Question

I am getting the following error:
java.sql.SQLException: Io exception: Connection reset by peer: JVM_recv in socket input stream read
     void oracle.jdbc.dbaccess.DBError.throwSqlException(java.lang.String, java.lang.String, int)
     void oracle.jdbc.dbaccess.DBError.throwSqlException(int, java.lang.Object)
     void oracle.jdbc.dbaccess.DBError.throwSqlException(java.io.IOException)
     void oracle.jdbc.driver.OracleStatement.executeNonQuery(boolean)
     void oracle.jdbc.driver.OracleStatement.doExecuteOther(boolean)
     void oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout()
     int oracle.jdbc.driver.OraclePreparedStatement.executeUpdate()
     boolean oracle.jdbc.driver.OraclePreparedStatement.execute()
     oracle.express.idl.ExpressMdmModule.MetadataPropertyBagUnion[] oracle.express.idl.ExpressMdmModule.MetadataProviderInterfaceStub.getMetadataPropertyBags(java.lang.String[])
     oracle.express.mdm.MetadataPropertyBag[] oracle.express.mdm.MetadataPropertyBagFetcher.fetchMetadataPropertyBags(java.lang.String[])
     oracle.express.mdm.MdmObject oracle.express.mdm.MdmMetadataProvider.getMetadataObject(java.lang.String)
     oracle.express.mdm.MdmSchema oracle.express.mdm.MdmMetadataProvider.getRootSchema()
     void mypackage3.olaptest.<init>()
     void mypackage3.olaptest.main(java.lang.String[])
java.lang.NullPointerException
     oracle.express.mdm.MetadataPropertyBag[] oracle.express.mdm.MetadataPropertyBagFetcher.fetchMetadataPropertyBags(java.lang.String[])
     oracle.express.mdm.MdmObject oracle.express.mdm.MdmMetadataProvider.getMetadataObject(java.lang.String)
     oracle.express.mdm.MdmSchema oracle.express.mdm.MdmMetadataProvider.getRootSchema()
     void mypackage3.olaptest.<init>()
     void mypackage3.olaptest.main(java.lang.String[])
***Exception encountered : java.lang.NullPointerException
Process exited with exit code 0.
... when running the following code
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
String url = "jdbc:oracle:thin:@jonm2000:1521:jonm";
String user = "sh";
String password = "sh";
oracle.jdbc.OracleConnection conn = (oracle.jdbc.OracleConnection)java.sql.DriverManager.getConnection(url, user, password);
ExpressTransactionProvider tp = new ExpressTransactionProvider();
ExpressDataProvider dp = new ExpressDataProvider(conn, tp);
dp.initialize();
MdmMetadataProvider mp = null;
mp = (MdmMetadataProvider) dp.getDefaultMetadataProvider();
MdmSchema root = mp.getRootSchema();
dp.close();
conn.close();
catch(Exception e) {
System.out.println("***Exception encountered : " + e.toString());
e.printStackTrace();
It is also brings down the Oracle database.
I am running:
JDeveloper 9.0.2.822.0
Oracle Database 9.0.2.1.0
The code I am running is pretty much copied from the Oracle OLAP API guide - does anyone know why I am getting problems?

Answer 1

It appears to be missing metadata. Since you are trying to get the schema, this is most likely a field that is required but not present (something silly, like labels). Try the following scripts posted below that verify metadata.
When creating solved level hierarchies, all of these dimensions require 4 special dimension attributes. All 4 of these dimension attributes require a level attribute to be mapped to a populated column in each of the solved hierarchies.
The 4 special attributes are:
GID
PARENT_GID
ET
PARENT_ET.
You can check if these attributes exist with the following query:
SELECT DA.OWNER,\n\
DA.DIMENSION_NAME,\n\
DA.ATTRIBUTE_NAME,\n\
NVL(DA.DISPLAY_NAME, DA.ATTRIBUTE_NAME),\n\
NVL(DA.DESCRIPTION, DA.ATTRIBUTE_NAME),\n\
(CASE WHEN D.DESCRIPTOR_VALUE = 'Long Description' THEN 4\n\
WHEN D.DESCRIPTOR_VALUE = 'Short Description' THEN 5\n\
WHEN D.DESCRIPTOR_VALUE = 'End Date' THEN 1\n\
WHEN D.DESCRIPTOR_VALUE = 'Time Span' THEN 2\n\
WHEN D.DESCRIPTOR_VALUE = 'Year Ago Period' THEN 3\n\
WHEN D.DESCRIPTOR_VALUE = 'Grouping ID' THEN 6\n\
WHEN D.DESCRIPTOR_VALUE = 'Parent Grouping ID' THEN 7\n\
WHEN D.DESCRIPTOR_VALUE = 'ET Key' THEN 8\n\
WHEN D.DESCRIPTOR_VALUE = 'Parent ET Key' THEN 9\n\
ELSE 0\n\
END)\n\
FROM ALL_OLAP2_DIM_ATTRIBUTES DA,\n\
all_olap2_entity_desc_uses edu,\n\
all_olap_descriptors d\n\
where\n\
DA.OWNER = EDU.ENTITY_OWNER (+)\n\
AND DA.DIMENSION_NAME = EDU.ENTITY_NAME (+)\n\
AND DA.ATTRIBUTE_NAME = EDU.CHILD_ENTITY_NAME (+)\n\
AND EDU.DESCRIPTOR_ID = D.DESCRIPTOR_ID (+)\n\
ORDER BY DA.OWNER, DA.DIMENSION_NAME, DA.ATTRIBUTE_NAME
For these 4 attributes, it's not enough that they just exist, (note you can name them whatever you want) but they also have to be marked as the appropriate type as per the above SQL.
Note also that the above SQL checks for other specially marked attributes such as Long/Short Description and End Date/Time Span. These attributes can exist without being marked as such (and can even be missing completely), and OLAP API will still function. However, I believe the OLAP API functions "better" if these attributes exist and are marked as special.
The below SQL will check your column mappings for all attributes. (As a general rule, you shouldn't have to worry too much about mapping any CWMLITE logical entity to a valid table/column, because the CWMLITE API should catch if you don't use a valid table/column.)
select owner,\n\
dimension_name,\n\
hierarchy_name,\n\
level_name,\n\
attribute_name,\n\
table_owner,\n\
table_name,\n\
column_name,\n\
(case when dtype = 'NUMBER' then 0\n\
when dtype = 'DOUBLE' then 5\n\
when dtype = 'FLOAT' then 4\n\
when dtype = 'DATE' then 7\n\
else 1 end)\n\
from\n\
all_olap2_dim_level_attr_maps\n\
ORDER BY OWNER, DIMENSION_NAME, HIERARCHY_NAME, ATTRIBUTE_NAME
Finally, note that any hierarchy which you map as coming from an AW will be a solved level hierarchy.