Author: [log in to unmask]
Date: Mon Oct 12 13:30:30 2015
New Revision: 3840
Log:
auto-retry connection
Modified:
java/trunk/conditions/src/main/java/org/hps/conditions/database/ConnectionParameters.java
Modified: java/trunk/conditions/src/main/java/org/hps/conditions/database/ConnectionParameters.java
=============================================================================
--- java/trunk/conditions/src/main/java/org/hps/conditions/database/ConnectionParameters.java (original)
+++ java/trunk/conditions/src/main/java/org/hps/conditions/database/ConnectionParameters.java Mon Oct 12 13:30:30 2015
@@ -9,6 +9,7 @@
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
+import java.util.logging.Logger;
/**
* This class encapsulates the parameters for connecting to a database, including host name, port, user and password.
@@ -21,6 +22,11 @@
* The default port number.
*/
public static final int DEFAULT_PORT = 3306;
+
+ /**
+ * Number of connection retries allowed.
+ */
+ private static final int MAX_ATTEMPTS = 10;
/**
* Configure the connection parameters from a properties file.
@@ -147,13 +153,24 @@
public Connection createConnection() {
final Properties connectionProperties = this.getConnectionProperties();
Connection connection = null;
- try {
- connection = DriverManager.getConnection(this.getConnectionString(), connectionProperties);
- connection.createStatement().execute("USE " + this.getDatabase());
- } catch (final SQLException x) {
- throw new RuntimeException("Failed to connect to database: " + this.getConnectionString(), x);
- }
- return connection;
+ int attempt = 0;
+ while (true) {
+ attempt++;
+ try {
+ connection = DriverManager.getConnection(this.getConnectionString(), connectionProperties);
+ connection.createStatement().execute("USE " + this.getDatabase());
+ } catch (final SQLException x) {
+ Logger.getLogger(this.getClass().getPackage().getName()).warning("Failed to connect to database " + this.getConnectionString() + " - " + x.getMessage());
+ if (attempt >= MAX_ATTEMPTS) {
+ throw new RuntimeException("Failed to connect to database after " + attempt + " attempts: " + this.getConnectionString(), x);
+ }
+ continue;
+ }
+ if (attempt > 1) {
+ Logger.getLogger(this.getClass().getPackage().getName()).warning("Connected to database " + this.getConnectionString() + " - after " + attempt + " attempts");
+ }
+ return connection;
+ }
}
/**
