Implementing Lookups Using DataBaseAccessor 

Procedure

Special Lookup API

For access using the special lookup API, developers do not require any knowledge of the structure of the payload. Instead, they pass the API string commands that are to be executed in the application system called.

Currently, there is one special lookup API for the JDBC adapter. Developers use the DataBaseAccessor class to implement this API.

The special lookup API is part of the mapping API (see the getDataBaseAccessor method of the LookupService class in the Javadoc documentation). For more information about these APIs, see SAP Developer Network at https://www.sdn.sap.com/irj/sdn/javadocs (SDN user required).

Example

import java.util.Iterator;
import java.util.Map;

import com.sap.aii.mapping.api.AbstractTransformation;
import com.sap.aii.mapping.api.StreamTransformationException;
import com.sap.aii.mapping.api.TransformationInput;
import com.sap.aii.mapping.api.TransformationOutput;
import com.sap.aii.mapping.lookup.*;

public class Parametraziation_Java extends AbstractTransformation {

   public void transform(TransformationInput in, TransformationOutput out)

         throws StreamTransformationException {

      DataBaseAccessor accessor = null;

      try {

         // 1. Read Import Parameter to get the channel ID for Lookup
         Channel channel = in.getInputParameters().getChannel("MYCHANNEL");

         // 2. Get a database accessor for the channel.
         accessor = LookupService.getDataBaseAccessor(channel);

         // 3. Prepare a sql statement "sqlStatement".
         String sqlStatement = "SELECT a, b, c FROM TABLE2";

         // 4. Execute lookup.
         DataBaseResult result = accessor.execute(sqlStatement);

         // 5. Iterate over the result rows.
         for (Iterator rows = result.getRows(); rows.hasNext();) {

            Map columnMap = (Map) rows.next();
            Object valueA = columnMap.get("a");
            Object valueB = columnMap.get("b");

         }

         // Steps 4. and 5. can be executed several times.

      } catch (Exception e) {

         // Exception Handling

      } finally {
         // 6. Close the accessor in order to free resources.

         if (accessor != null)
            accessor.close();
      }
   }
}