Changeset 7533

Timestamp:

Nov 27, 2018, 10:25:31 AM (4 years ago)

Author:

Nicklas Nordborg

Message:

References #2130: Upgrade 3-rd party libraries

The change made in [7521] did not work when running inside Tomcat. Probably due to classloader issues where the DriverManager is initialized early in the startup process before web apps are accessible. It can be solved by repeating the registration with the correct class loader (implicit via ServiceLoader).

File:

• trunk/src/core/net/sf/basedb/core/HibernateUtil.java (modified) (4 diffs)

trunk/src/core/net/sf/basedb/core/HibernateUtil.java

@@ -64 +64 @@
 import java.util.Map;
 import java.util.Properties;
+import java.util.ServiceLoader;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
@@ -74 +75 @@
 import java.sql.ResultSet;
 import java.sql.DatabaseMetaData;
+import java.sql.Driver;
 import java.sql.SQLException;
 import java.io.IOException;
@@ -288 +290 @@
       throw new ConfigurationException("PostgreSQLDialect has been deprecated. Use PostgreSQL9Dialect instead (base.config).");
     }
+    String dbUrl = Config.getString("db.url", "");
+    checkJdbcDriver(dbUrl);
+    
     Properties baseConfig = new Properties();
     baseConfig.setProperty("hibernate.dialect", dialect);
-    baseConfig.setProperty("hibernate.connection.url", Config.getString("db.url", ""));
+    baseConfig.setProperty("hibernate.connection.url", dbUrl);
     baseConfig.setProperty("hibernate.connection.username", Config.getString("db.username", ""));
     baseConfig.setProperty("hibernate.connection.password", Config.getString("db.password", ""));
@@ -296 +301 @@
   }
 
+  /**
+    Check that a JDBC driver is registered and try to load a driver if not.
+  */
+  private static void checkJdbcDriver(String dbUrl)
+  {
+    Driver driver = null;
+    try
+    {
+      driver = DriverManager.getDriver(dbUrl);
+    }
+    catch (SQLException ex)
+    {
+      log.warn("JDBC driver for '" + dbUrl + "' is not registered. Trying to re-load via ServiceLoader.");
+      // The driver has not been registered which can happen when the DriverManager class
+      // is initialized by the "wrong" class loader (eg. Tomcat will load this in a bootstrap
+      // class loader which doesn't have access to JAR files in the WEB-INF/lib directory)
+      // So, we need let the drivers register themselves via the ServiceLoader
+      ServiceLoader<Driver> s = ServiceLoader.load(Driver.class);
+      Iterator<Driver> it = s.iterator();
+      while (it.hasNext())
+      {
+        Driver d = it.next();
+        if (d != null)
+        {
+          boolean acceptUrl = false;
+          try
+          {
+            acceptUrl = d.acceptsURL(dbUrl);
+          }
+          catch (SQLException ex2)
+          {}
+          log.info("Loaded JDBC driver " + d.getClass().getName() + 
+              "; version=" + d.getMajorVersion() + "." + d.getMinorVersion()+
+              "; acceptsURL="+acceptUrl);
+          if (acceptUrl && driver == null)
+          {
+            driver = d;
+          }
+        }
+      }
+    }
+    if (driver == null)
+    {
+      throw new ConfigurationException("Could not find a suitable JDBC driver for URL: " + dbUrl);
+    }
+    log.info("Accepted JDBC driver " + driver.getClass().getName() + 
+        "; version=" + driver.getMajorVersion() + "." + driver.getMinorVersion());
+  }
+  
   /**
     Read all mapping files, which must be named <code>Class.hbm.xml</code> where class