diff -u -r1.2 -r1.3
--- DatabaseConditionsReader.java	18 Sep 2013 02:33:16 -0000	1.2
+++ DatabaseConditionsReader.java	18 Sep 2013 21:03:23 -0000	1.3
@@ -2,6 +2,9 @@

 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;

+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;

 import java.io.IOException;
 import java.io.InputStream;
 import java.sql.Connection;

@@ -16,11 +19,24 @@

 import org.lcsim.hps.conditions.svt.SvtCalibrationConverter;
 
 /**

- * This a refactored version of Dima's ExampleDatabaseConditionsReader that attempts
- * to handle the conditions and their meta data more generically.  (Work in progress!)

+ * This a rewritten version of Dima's ExampleDatabaseConditionsReader that attempts to handle 
+ * the conditions and their meta data in a fully generic fashion.
+ * 
+ * In order to override the default database connection parameters, the system property
+ * <code>hps.conditions.db.configuration</code> should point to a properties file defining 
+ * the variables read by ConnectionParameters (see that class for details).  Otherwise, the 
+ * defaults will be used to connect to a test database at SLAC.
+ * 
+ * Setting custom connection properties would look something like the following from the CL:
+ * 
+ *     java -Dhps.conditions.db.configuration=/path/to/my/config.prop [...]
+ * 
+ * Currently, this class should "know" about all the converters that are needed for loading
+ * conditions data.  The SVT is the only example currently, but more will be added as they
+ * are created.

  * 
  * @author jeremym

- * @version $Id: DatabaseConditionsReader.java,v 1.2 2013/09/18 02:33:16 jeremy Exp $

+ * @version $Id: DatabaseConditionsReader.java,v 1.3 2013/09/18 21:03:23 jeremy Exp $

  */
 public class DatabaseConditionsReader extends ConditionsReader {
     

@@ -42,17 +58,45 @@

     /** Current maximum run number.  This is updated as conditions are loaded. */
     private int maxRun = Integer.MIN_VALUE;
 

+    /** This maps conditions types to their table, field, and set id. */

     private final HashMap<String, byte[]> propertyCache = new HashMap<String, byte[]>();
 
     /**

-     * Class constructor taking a ConditionsReader, which is probably a ZipFileConditionsReader.
-     * This constructor is automatically called by the ConditionsManager when this type has been
-     * requested via the detector properties file.

+     * Class constructor taking a ConditionsReader.  This constructor is automatically called 
+     * by the ConditionsManager when this type of reader has been requested via the detector 
+     * properties file.

      * 
      * @param reader The basic ConditionsReader allowing access to the detector.
      */
     public DatabaseConditionsReader(ConditionsReader reader) {
         this.reader = reader;

+        
+        // Setup possible custom database parameters.
+        setupConnectionParameters();        
+    }
+    
+    /**
+     * Setup custom database connection parameters if there is a configuration file pointed to by 
+     * a system property.
+     */
+    public void setupConnectionParameters() {
+        Object o = System.getProperties().get("hps.conditions.db.configuration");
+        if (o != null) {
+            String config = o.toString();
+            Properties p;
+            if (config != null) {
+                p = new Properties();
+                try {
+                    p.load(new FileInputStream(new File(config)));
+                } catch (FileNotFoundException e) {
+                    throw new RuntimeException(e);
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+                this.connectionParameters = ConnectionParameters
+                        .fromProperties(p);
+            }
+        }

     }
 
     /**

@@ -128,10 +172,11 @@

      */
     private final void cacheMetadata(int run) throws SQLException, IOException {
         

-        String query = "SELECT data_ident, runStart, runEnd, calib_type FROM rd_hps_cond.conditions_test WHERE "
-                + "runStart <= "

+        // Query for fetching the validity records matching this run.
+        String query = "SELECT data_ident, run_start, run_end, calib_type FROM rd_hps_cond.conditions_test WHERE "
+                + "run_start <= "

                 + run

-                + " AND runEnd >= "

+                + " AND run_end >= "

                 + run
                 + " AND level = 'PROD'";
 

@@ -140,21 +185,23 @@

         try {
             statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery(query);

+            
+            // Iterate over conditions records.

             while (resultSet.next()) {
                 

-                // String containing conditions set meta data.

+                // The data_ident field.

                 data = resultSet.getString(1);
                 

-                // The minimum run.

+                // The minimum run number.

                 minRun = resultSet.getInt(2);
                 

-                // The maximum run.

+                // The maximum run number.

                 maxRun = resultSet.getInt(3);
                 
                 // The type of the calibration.
                 String calibrationType = resultSet.getString(4);
                 

-                // Cache the properties for this condition by type.

+                // Cache the data_ident by condition type for later use by converters.

                 addProperty(calibrationType, data);
             }
         } finally {

@@ -168,6 +215,15 @@

         }            
     }
 

+    /**
+     * Register data_ident properties for a certain condition type.  
+     * This includes table name, column name, and the id field.  
+     * The information is later used by the converters to create the application 
+     * data objects from SQL queries.
+     * @param key The key of the conditions. (for instance "svt_calibration")
+     * @param data The raw string data from the data_ident field in the database.
+     * @throws IOException if the data format is wrong.
+     */

     private void addProperty(String key, String data) throws IOException {
         Properties p = new Properties();
         String[] d = data.trim().split(":");

@@ -183,7 +239,12 @@

         propertyCache.put(key, stream.toByteArray());
     }
             

+    /**
+     * Register the default conditions converters.
+     * @param manager The ConditionsManager.
+     */

     private void registerConditionsConverters(ConditionsManager manager) {
         manager.registerConditionsConverter(new SvtCalibrationConverter(connectionParameters));