4 Discovering the Available Metadata

Example 4-2 Getting the Root MdmSchema

MdmSchema rootSchema = mp.getRootSchema();

Example 4-3 Getting MdmDimension Objects

List dims = rootSchema.getDimensions();

Example 4-4 Getting Subschemas

List subSchemas = rootSchema.getSubSchemas();

Example 4-5 Getting the MdmMeasureDimension

MdmMeasureDimension mdmMeasureDim =
             (MdmMeasureDimension) rootSchema.getMeasureDimension();
List mdmMeasureDimMeasures = mdmMeasureDim.getMeasures();
Iterator mdmMeasureDimMeasuresItr = mdmMeasureDimMeasures.iterator();
MdmMeasure measure = null;
println("The measures in the MdmMeasureDimension are:");
while (mdmMeasureDimMeasuresItr.hasNext()) 
{
  measure = (MdmMeasure) mdmMeasureDimMeasuresItr.next();
  println("\t" + measure.getName());
}

Example 4-6 Getting the Dimensions of an MdmMeasure

List dimsOfUnits = mdmUnits.getDimensions();

The getMeasureInfo method, which is in the Example 4-9, shows one way to iterate through the MdmPrimaryDimension objects belonging to an MdmMeasure.

Example 4-7 Getting the MdmHierarchy Components of an MdmPrimaryDimenison

List mdmHiers = mdmPrimaryDim.getHierarchies();
Iterator mdmHiersItr = mdmHiers.iterator();
println("The MdmHierarchy components of " + mdmPrimaryDim.getName() + " are:");
while (mdmHiersItr.hasNext()) 
{
  MdmHierarchy mdmHier = (MdmHierarchy) mdmHiersItr.next();
  println("\t" + mdmHier.getName());
} 

The getDimInfo method in Example 4-9 shows one way to get the following metadata objects for an MdmDimension.

Example 4-9 Discovering the OLAP Metadata

package oracle.olapi.examples.chapter4;

import oracle.express.olapi.data.full.ExpressDataProvider;
import oracle.olapi.examples.*;
import oracle.olapi.metadata.mdm.*;
import oracle.olapi.data.source.Source;

import java.util.List;
import java.util.Iterator;

/**
 * Discovers the MDM metadata objects for the GLOBALAW analytic workspace.
 */
public class SampleMetadataDiscoverer10g extends ContextExample 
{
  private ExpressDataProvider dp = null;
  private MdmSchema root = null;
  private MdmPrimaryDimension storedMdmDim = null;
  private  MyMdmObjectVisitor mdmObjVisitor = new MyMdmObjectVisitor(); 

  private String sp3 = "   "; // Contains spaces for formatting output.
  private String sp6 = (sp3 + sp3);
  private String sp9 = (sp6 + sp3);
  private String errorMessage;  // Contains an error message.

  /**
   * Connects to an Oracle Database instance and gets MDM metadata objects.
   */
  protected void run() throws Exception
  {
    getLogger().setVerbose(true);   // Specify true to display more information.
    //getLogger().setVerbose(false);

    // Get the DataProvider associated with the connection.
    dp = getExpressDataProvider();

    // Get the default MdmMetadataProvider from the DataProvider.
    MdmMetadataProvider mp = null;
    mp = (MdmMetadataProvider) dp.getDefaultMetadataProvider();

    // Get metadata information about the root MdmSchema and the subschemas.
    root = mp.getRootSchema();
    showInfo("The root MdmSchema is " + root.getName() + ".");

    // To get information about all of metadata objects associated with the root
    // MdmSchema, set getAllMetadata to true.
    // To get information about the metadata objects for a single subschema,
    // specify the subschema in the call to getSubschemaByName and set
    // getAllMetadata to false.

    // Get the metadata objects for the specified subschema only.
    MdmSchema subSchema = getSubschemaByName(root, "GLOBALAW_SCHEMA");

    boolean getAllMetadata = false;
    // boolean getAllMetadata = true;

    if (!getAllMetadata)
    {
      getSchemaInfo(subSchema, getLogger().isVerbose());
    }
    else
    {
      getSchemaInfo(root, getLogger().isVerbose());
    }

    // The storedMdmDim object is an MdmPrimaryDimension that is assigned in
    // the getSchemaInfo method. The getSource method of the MdmPrimaryDimension
    // gets the Source object for the MdmPrimaryDimension.
    showOutput("\nGetting the primary Source object for dimension " +
                storedMdmDim.getName() + ".");
    Source dimSource = storedMdmDim.getSource();
    showInfo("The ID of the Source for " + storedMdmDim.getName() + " is " +
             dimSource.getID() + ".\n");
  }

 /**
  * Gets the specified subschema of the root MdmSchema.
  *
  * @param rootSchema The root MdmSchema.
  * @param schemaName The name of a subschema.
  * @return The specified MdmSchema that is a subschema of the root schema.
  */
  public MdmSchema getSubschemaByName(MdmSchema rootSchema, String schemaName)
  {
    MdmSchema subschema = null;
    try
    {
      List subSchemas = rootSchema.getSubSchemas();
      Iterator subSchemaIter = subSchemas.iterator();
      while (subSchemaIter.hasNext())
      {
        subschema = (MdmSchema) subSchemaIter.next();
        if (subschema.getName().equals(schemaName))
        {
          return subschema;
        }
      }
    }
    catch (Exception e)
    {
      showError(sp3 + "Encountered exception " + e);
    }
    if(subschema != null)
    {
      showOutput("Could not find subschema " + schemaName + ".");
      showOutput("Using subschema " + subschema.getName() + " instead.\n");
      return subschema;
    }
    else
    {
      showOutput("Could not find any subschema.");
      showOutput("Using the root schema.\n");
      return rootSchema;
    }
  }

  /**
   * Gets information about the specified MdmSchema and any subschemas of that
   * MdmSchema.
   */
  public void getSchemaInfo(MdmSchema schema, boolean verbose) 
  {
    if (schema == root) 
    {
      showOutput("The MdmPrimaryDimension objects of the root schema are:");
    }
    else 
    {
      showOutput("\nSchema: " + schema.getName());
      showOutput("The MdmPrimaryDimension objects of schema "
                 + schema.getName() + " are:");
    }

    // Get the MdmPrimaryDimension objects of the MdmSchema.
    int i = 1;
    try 
    {
      List dims = schema.getDimensions();
      Iterator dimIter = dims.iterator();

      // Iterate through the list of MdmPrimaryDimension objects and get
      // information about each one.
      while (dimIter.hasNext()) 
      {
        MdmPrimaryDimension oneDim = (MdmPrimaryDimension) dimIter.next();

        // Save a dimension for later use.
        if ( storedMdmDim == null ) 
          storedMdmDim = oneDim;

        if (verbose)
        {
          getDimInfo(i, oneDim);
          i++;
        }
        else
        {
          showOutput(sp3 + oneDim.getName());
        }
      }
    }
    catch (Exception e)
    {
       showError(sp3 + "Encountered exception " + e);
    }

    // If the MdmSchema is the root MdmSchema, get the MdmMeasureDimension
    // and get the measures of the MdmMeasureDimension.
    MdmMeasureDimension mdmMeasureDim = (MdmMeasureDimension) 
                                         schema.getMeasureDimension();
    if (mdmMeasureDim != null) 
    {
      showOutput("The MdmMeasure objects of the MdmMeasureDimension are:");
      List mdmMeasures = mdmMeasureDim.getMeasures();
      Iterator mdmMeasuresIter = mdmMeasures.iterator();
      int count = 1;
      while (mdmMeasuresIter.hasNext()) 
      {
        MdmMeasure oneMeasure = (MdmMeasure) mdmMeasuresIter.next();
        getMeasureInfo(count, oneMeasure, verbose);
        if (verbose)
          showOutput("");
        count++;
      }
    }

    // Get the MdmMeasure objects of the MdmSchema.
    try 
    {
      List mdmMeasures = schema.getMeasures();
      if (mdmMeasures.size() > 0) 
      {
        Iterator mdmMeasuresIter = mdmMeasures.iterator();
        showOutput("The MdmMeasure objects of schema " + schema.getName()
                    + " are:");
        int count = 1;
        while (mdmMeasuresIter.hasNext())
        {
          MdmMeasure oneMeasure = (MdmMeasure) mdmMeasuresIter.next();
          getMeasureInfo(count, oneMeasure, verbose);
          count++;
        }
      }
    }
    catch (Exception e) 
    {
      showError(sp3 + "Encountered exception " + e);
    }

    // Get the subschema information for the MdmSchema.
    try 
    {
      List subSchemas = schema.getSubSchemas();
      Iterator subSchemaIter = subSchemas.iterator();
      while (subSchemaIter.hasNext()) 
      {
        MdmSchema oneSchema = (MdmSchema) subSchemaIter.next();
        getSchemaInfo(oneSchema, verbose);
      }
    }
    catch (Exception e) 
    {
      showError(sp3 + "Encountered exception " + e);
    }
  }

  /**
   * Gets information about an MdmMeasure.
   *
   * @param count An integer that tracks the number of MdmMeasure objects.
   * @param dim The MdmMeasure about which to get information.
   * @param verbose A boolean that specifies whether to display more or less
   *                information.
   */
  public void getMeasureInfo(int count, MdmMeasure measure, boolean verbose) 
  {
    showOutput(count + ". " + measure.getName());
    if (verbose) 
    {
      // Get the MdmDimension objects associated with the MdmMeasure.
      try 
      {
        List mDims = measure.getDimensions();
        Iterator mDimIter = mDims.iterator();
        showOutput(sp3 + "The dimensions of the measure are:");
        while (mDimIter.hasNext())
        {
          MdmDimension dim = (MdmDimension) mDimIter.next();
          showOutput(sp6 + dim.getName()); 
        }
        if (verbose)
          showOutput("");
      }
      catch (Exception e) 
      {
        showError(sp3 + "Encountered exception " + e);
      }
    }
  }

  /**
   * Gets information about an MdmDimension.
   * @param count An integer that indicates the position of the
   *              MdmPrimaryDimension in the list of dimensions of the
   *              MdmSchema.
   * @param dim The MdmPrimaryDimension about which to get information.
   */
  public void getDimInfo(int count, MdmPrimaryDimension dim) 
  {
    showOutput(count + ". " + dim.getName());
    String description = dim.getDescription();

    // Determine the type of the MdmPrimaryDimension.
    String objType  = (String) dim.acceptVisitor(mdmObjVisitor,
                                                 mdmObjVisitor.OBJTYPE);
    showOutput(sp3 + objType);

    // Get the MdmAttribute objects associated with the MdmPrimaryDimension.
    showInfo(sp3 + "The attributes of the dimension are:");
    try
    {
      List attributes = dim.getAttributes();
      Iterator attrIter = attributes.iterator();
      while (attrIter.hasNext())
      {
        MdmAttribute attr = (MdmAttribute) attrIter.next();
        showOutput(sp6 + attr.getName());
      }
    }
    catch (Exception e)
    {
      showError(sp3 + "Encountered exception " + e);
    }

    // Get information about the MdmHierarchy objects of the 
    // MdmPrimaryDimension.
    getHierInfo(dim);
    showOutput("");
  }

  /**
   * Gets the MdmHierarchy components of an MdmPrimaryDimension.
   *
   * @param dim The MdmPrimarydimension for which to get the MdmHierarchy
   *            objects.
   */
  public void getHierInfo(MdmPrimaryDimension dim) 
  {
    List mdmHiers = dim.getHierarchies();
    Iterator mdmHiersItr = mdmHiers.iterator();
    MdmHierarchy mdmHier = null;
    MdmLevelHierarchy mdmLevelHier = null;
    int i = 1;
    showOutput(sp3 + "The MdmHierarchy components of " + dim.getName()                + " are:");
    while (mdmHiersItr.hasNext()) 
    {
      mdmHier = (MdmHierarchy) mdmHiersItr.next();
      showOutput(sp3 + i + ". " + mdmHier.getName());
      String objType  = (String) mdmHier.acceptVisitor(mdmObjVisitor,
                                                       mdmObjVisitor.OBJTYPE);
      showOutput(sp6 + objType);

      if (mdmHier.isDefaultHierarchy()) 
      {
        showOutput(sp6 + mdmHier.getName() + " is the default" +                        " MdmHierarchy of " + dim.getName() + ".");
      }
      if (mdmHier instanceof MdmLevelHierarchy)
      {
        mdmLevelHier = (MdmLevelHierarchy) mdmHier;
        getLevelInfo(mdmLevelHier);
      }
     i++;
    }
  }

  /**
   * Gets the MdmLevel components of an MdmLevelHierarchy.
   *
   * @param mdmHier The MdmLevelHierarchy about which to get information.
   */
  public void getLevelInfo(MdmLevelHierarchy mdmHier)
  {
    List mdmLevels = mdmHier.getLevels();
    Iterator mdmLevelsItr = mdmLevels.iterator();
    showOutput(sp6 + "The levels of the hierarchy are:");
    while (mdmLevelsItr.hasNext()) 
    {
      MdmLevel mdmLevel = (MdmLevel) mdmLevelsItr.next();
      showOutput(sp9 + mdmLevel.getName());
    }
  }

  // The showError and showInfo methods of this class call methods of the same
  // name of the Logger object associated with this object.
  // The showOutput method calls the println method of the Logger.

  /**
   * Creates a new SampleMetadataDiscoverer10g object and calls the execute
   * method, which the class inherits from the ContextExample superclass.
   *
   * @param args Arguments supplied on the Java command line.
   */
  public static void main(String[] args) 
  {
    new SampleMetadataDiscoverer().execute(args);
  }
}