Add logging when a context fails to unregister a JDBC driver.

Don't unregister the jdbc-obdc bridge driver that is loaded by the system classloader.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@885231 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/java/org/apache/catalina/loader/JdbcLeakPrevention.java b/java/org/apache/catalina/loader/JdbcLeakPrevention.java
index 1fd7ea2..1aa1034 100644 (file)
--- a/java/org/apache/catalina/loader/JdbcLeakPrevention.java
+++ b/java/org/apache/catalina/loader/JdbcLeakPrevention.java
@@ -21,7 +21,9 @@ package org.apache.catalina.loader;
 import java.sql.Driver;
 import java.sql.DriverManager;
 import java.sql.SQLException;
+import java.util.ArrayList;
 import java.util.Enumeration;
+import java.util.List;
 
 /**
  * This class is loaded by the {@link WebappClassLoader} to enable it to
@@ -36,14 +38,28 @@ import java.util.Enumeration;
  */
 public class JdbcLeakPrevention {
 
-    public void clearJdbcDriverRegistrations() throws SQLException {
+    /* 
+     * This driver is visible to all classloaders but is loaded by the system
+     * class loader so there is no need to unload it.
+     */
+    private static final String JDBC_ODBC_BRIDGE_DRIVER =
+        "sun.jdbc.odbc.JdbcOdbcDriver";
+    
+    public List<String> clearJdbcDriverRegistrations() throws SQLException {
+        List<String> driverNames = new ArrayList<String>();
+        
         // Unregister any JDBC drivers loaded by the class loader that loaded
         // this class - ie the webapp class loader
         Enumeration<Driver> drivers = DriverManager.getDrivers();
         while (drivers.hasMoreElements()) {
             Driver driver = drivers.nextElement();
+            if (JDBC_ODBC_BRIDGE_DRIVER.equals(
+                    driver.getClass().getCanonicalName())) {
+                continue;
+            }
+            driverNames.add(driver.getClass().getCanonicalName());
             DriverManager.deregisterDriver(driver);
         }
-        
+        return driverNames;
     }
 }

diff --git a/java/org/apache/catalina/loader/LocalStrings.properties b/java/org/apache/catalina/loader/LocalStrings.properties
index 37ed504..297af31 100644 (file)
--- a/java/org/apache/catalina/loader/LocalStrings.properties
+++ b/java/org/apache/catalina/loader/LocalStrings.properties
@@ -33,6 +33,7 @@ webappClassLoader.jdbcRemoveFailed=JDBC driver de-registration failed
 webappClassLoader.jdbcRemoveStreamError=Exception closing input stream during JDBC driver de-registration
 webappClassLoader.stopped=Illegal access: this web application instance has been stopped already.  Could not load {0}.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
 webappClassLoader.readError=Resource read error: Could not load {0}.
+webappClassLoader.uncleareredReferenceJbdc=A web application registered the JBDC driver [{0}] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.   
 webappClassLoader.wrongVersion=(unable to load class {0})
 webappLoader.addRepository=Adding repository {0}
 webappLoader.deploy=Deploying class repositories to work directory {0}

diff --git a/java/org/apache/catalina/loader/WebappClassLoader.java b/java/org/apache/catalina/loader/WebappClassLoader.java
index cd82d6f..74ad4d0 100644 (file)
--- a/java/org/apache/catalina/loader/WebappClassLoader.java
+++ b/java/org/apache/catalina/loader/WebappClassLoader.java
@@ -42,6 +42,7 @@ import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Vector;
 import java.util.jar.Attributes;
@@ -1672,8 +1673,13 @@ public class WebappClassLoader
                 defineClass("org.apache.catalina.loader.JdbcLeakPrevention",
                     classBytes, 0, offset);
             Object obj = lpClass.newInstance();
-            obj.getClass().getMethod(
+            @SuppressWarnings("unchecked")
+            List<String> driverNames = (List<String>) obj.getClass().getMethod(
                     "clearJdbcDriverRegistrations").invoke(obj);
+            for (String name : driverNames) {
+                log.error(sm.getString(
+                        "webappClassLoader.uncleareredReferenceJbdc", name));
+            }
         } catch (Exception e) {
             // So many things to go wrong above...
             log.warn(sm.getString("webappClassLoader.jdbcRemoveFailed"), e);