Made connection retry parameters configurable

src/java/org/jivesoftware/database/DbConnectionManager.java

@@ -74,55 +74,59 @@ public class DbConnectionManager {
     /** True if the database supports the Statement.setFetchSize()) method. */
     static boolean pstmt_fetchSizeSupported = true;
 
+    private static final String SETTING_DATABASE_MAX_RETRIES = "database.defaultProvider.maxRetries";
+    private static final String SETTING_DATABASE_RETRY_DELAY = "database.defaultProvider.retryDelay";
 
     private static DatabaseType databaseType = DatabaseType.unknown;
 
     private static SchemaManager schemaManager = new SchemaManager();
 
     /**
-     * Returns a database connection from the currently active connection
-     * provider. An exception will be thrown if no connection was found.
-     * (auto commit is set to true).
-     *
-     * @return a connection.
-     * @throws SQLException if a SQL exception occurs or no connection was found.
+     * Ensures that the connection provider exists and is set
      */
-    public static Connection getConnection() throws SQLException {
-        if (connectionProvider == null) {
+    private static void ensureConnectionProvider() {
+        if (connectionProvider != null) return;
+        
         synchronized (providerLock) {
-                if (connectionProvider == null) {
-                    // Attempt to load the connection provider classname as
-                    // a Jive property.
+            if (connectionProvider != null) return;
+            
+            // Attempt to load the connection provider classname as a Jive property.
             String className = JiveGlobals.getXMLProperty("connectionProvider.className");
             if (className != null) {
                 // Attempt to load the class.
                 try {
                     Class conClass = ClassUtils.forName(className);
                     setConnectionProvider((ConnectionProvider)conClass.newInstance());
-                        }
-                        catch (Exception e) {
+                } catch (Exception e) {
                     Log.warn("Failed to create the " +
                             "connection provider specified by connection" +
                             "Provider.className. Using the default pool.", e);
                     setConnectionProvider(new DefaultConnectionProvider());
                 }
-                    }
-                    else {
+            } else {
                 setConnectionProvider(new DefaultConnectionProvider());
             }
         }
     }
-        }
 
-        // TODO: May want to make these settings configurable
-        Integer retryCnt = 0;
-        Integer retryMax = 10;
-        Integer retryWait = 250; // milliseconds
-        Connection con = null;
+    /**
+     * Returns a database connection from the currently active connection
+     * provider. An exception will be thrown if no connection was found.
+     * (auto commit is set to true).
+     *
+     * @return a connection.
+     * @throws SQLException if a SQL exception occurs or no connection was found.
+     */
+    public static Connection getConnection() throws SQLException {
+        ensureConnectionProvider();
+
+        Integer currentRetryCount = 0;
+        Integer maxRetries = JiveGlobals.getIntProperty(SETTING_DATABASE_MAX_RETRIES, 10);
+        Integer retryWait = JiveGlobals.getIntProperty(SETTING_DATABASE_RETRY_DELAY, 250); // milliseconds
         SQLException lastException = null;
         do {
             try {
-            	con = connectionProvider.getConnection();
+                Connection con = connectionProvider.getConnection();
                 if (con != null) {
                     // Got one, lets hand it off.
                     // Usually profiling is not enabled. So we return a normal 
@@ -130,8 +134,7 @@ public class DbConnectionManager {
                     // connection with a profiled connection.
                     if (!profilingEnabled) {
                         return con;
-                    }
-                    else {
+                    } else {
                         return new ProfiledConnection(con); 
                     }
                 }
@@ -139,19 +142,20 @@ public class DbConnectionManager {
                 // TODO distinguish recoverable from non-recoverable exceptions.
                 lastException = e;
                 Log.info("Unable to get a connection from the database pool " +
-            			"(attempt "+retryCnt+" out of "+retryMax+").", e);
+                        "(attempt " + currentRetryCount + " out of " + maxRetries + ").", e);
             }
+            
             try {
                 Thread.sleep(retryWait);
+            } catch (Exception e) {
+                // Ignored, the thread was interrupted while waiting, so no need to log either
             }
-            catch (Exception e) {
-                // Ignored
-            }
-            retryCnt++;
-        } while (retryCnt <= retryMax);
+            currentRetryCount++;
+        } while (currentRetryCount <= maxRetries);
+        
         throw new SQLException("ConnectionManager.getConnection() " +
-                "failed to obtain a connection after " + retryCnt +" retries. " +
-                "The exception from the last attempt is as follows: "+lastException);
+                "failed to obtain a connection after " + currentRetryCount + " retries. " +
+                "The exception from the last attempt is as follows: " + lastException);
     }
 
     /**