Fixes #474 : fix ConcurrentModificationException in StdSchedulerFacto…

…ry.overrideWithSysProps

quartz-core/src/main/java/org/quartz/impl/StdSchedulerFactory.java

@@ -66,6 +66,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Enumeration;
+
 /**
  * <p>
  * An implementation of <code>{@link org.quartz.SchedulerFactory}</code> that
@@ -441,19 +443,20 @@ public void initialize() throws SchedulerException {
             }
         }
 
-        initialize(overrideWithSysProps(props));
+        initialize(overrideWithSysProps(props, getLog()));
     }
 
     /**
      * Add all System properties to the given <code>props</code>.  Will override
      * any properties that already exist in the given <code>props</code>.
      */
-    private Properties overrideWithSysProps(Properties props) {
+    // Visible for testing
+    static Properties overrideWithSysProps(Properties props, Logger log) {
         Properties sysProps = null;
         try {
             sysProps = System.getProperties();
         } catch (AccessControlException e) {
-            getLog().warn(
+            log.warn(
                 "Skipping overriding quartz properties with System properties " +
                 "during initialization because of an AccessControlException.  " +
                 "This is likely due to not having read/write access for " +
@@ -464,7 +467,17 @@ private Properties overrideWithSysProps(Properties props) {
         }
 
         if (sysProps != null) {
-            props.putAll(sysProps);
+            // Use the propertyNames to iterate to avoid 
+            // a possible ConcurrentModificationException
+            Enumeration<?> en = sysProps.propertyNames();
+            while (en.hasMoreElements()) {
+                Object name = en.nextElement();
+                Object value = sysProps.get(name);
+                if (name instanceof String && value instanceof String) {
+                    // Properties javadoc discourages use of put so we use setProperty
+                    props.setProperty((String) name, (String) value);
+                }
+            }
         }
 
         return props;

quartz-core/src/test/java/org/quartz/impl/StdSchedulerFactoryTest.java

@@ -0,0 +1,38 @@
+/*
+ * All content copyright Terracotta, Inc., unless otherwise indicated. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.quartz.impl;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Properties;
+
+import org.junit.Test;
+import org.slf4j.helpers.NOPLogger;
+
+public class StdSchedulerFactoryTest {
+
+	@Test
+	public void testOverrideSystemProperties() {
+	    Properties p = new Properties();
+	    p.setProperty("nonsense1", "hello1");
+	    p.setProperty("nonsense2", "hello2");
+	    System.setProperty("nonsense1", "boo1");
+	    String osName = System.getProperty("os.name");
+	    Properties q = StdSchedulerFactory.overrideWithSysProps(p, NOPLogger.NOP_LOGGER);
+	    assertEquals("boo1", q.get("nonsense1"));
+	    assertEquals(osName, q.get("os.name"));
+	}
+}