I think there was a reason ParameterizedMessage got the strings up front, but I 
don't know what it is. If it is possible to defer that I think that would be 
great.

Sent from my iPad

> On Aug 10, 2014, at 6:19 AM, Remko Popma <[email protected]> wrote:
> 
> Ralph is saying that lazy initialization is better because the message may be 
> filtered out and end up not being logged. In that case we don't need to pay 
> the cost of constructing the formatted string unnecessarily. 
> 
> I'll take a look at it again later next week. 
> 
> (ParameterizedMessage was not lazy enough then: it always makes strings of 
> its arguments in the constructor. That should be postponed until 
> getFormattedMessage() is called.)
> 
> 
>> On Sunday, August 10, 2014, Gary Gregory <[email protected]> wrote:
>> Does that mean more fields can be made final? 
>> 
>> Gary
>> 
>> 
>> -------- Original message --------
>> From: Remko Popma
>> Date:08/10/2014 08:55 (GMT-05:00)
>> To: Log4J Developers List
>> Subject: Re: svn commit: r1617051 - in /logging/log4j/log4j2/trunk: 
>> log4j-api/src/main/java/org/apache/logging/log4j/message/ 
>> log4j-api/src/test/java/org/apache/logging/log4j/message/ src/changes/ 
>> src/site/xdoc/manual/
>> 
>> True. Until now getFormattedMessage() used lazy initialization in many 
>> messages. The LOG4J2-763 changes mean initialization always happens in the 
>> constructor so the code can be simplified. I won't have time for this 
>> tonight though. 
>> 
>> Sent from my iPhone
>> 
>> > On 2014/08/10, at 21:12, Gary Gregory <[email protected]> wrote:
>> > 
>> > Instead of calling getFormattedMessage(), how about refactoring it and 
>> > call an initSomething method. This will make the call sites less smelly of 
>> > programming by side effect. 
>> > 
>> > Gary
>> > 
>> > 
>> > -------- Original message --------
>> > From: [email protected]
>> > Date:08/10/2014 02:40 (GMT-05:00) 
>> > To: [email protected]
>> > Subject: svn commit: r1617051 - in /logging/log4j/log4j2/trunk: 
>> > log4j-api/src/main/java/org/apache/logging/log4j/message/ 
>> > log4j-api/src/test/java/org/apache/logging/log4j/message/ src/changes/ 
>> > src/site/xdoc/manual/
>> > 
>> > Author: rpopma
>> > Date: Sun Aug 10 06:40:14 2014
>> > New Revision: 1617051
>> > 
>> > URL: http://svn.apache.org/r1617051
>> > Log:
>> > LOG4J2-763: Improved FormattedMessage, StringFormattedMessage, 
>> > LocalizedMessage, MessageFormatMessage and ObjectMessage for asynchronous 
>> > logging to ensure the formatted message does not change even if parameters 
>> > are modified by the application. Improved docs for MapMessage and 
>> > StructuredDataMessage. Improved site docs.
>> > 
>> > Added:
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java
>> >    (with props)
>> > Modified:
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/FormattedMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/LocalizedMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MapMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MessageFormatMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/ObjectMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StringFormattedMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/FormattedMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/LocalizedMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MapMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MessageFormatMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ObjectMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ParameterizedMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StringFormattedMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java
>> >     
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ThreadDumpMessageTest.java
>> >     logging/log4j/log4j2/trunk/src/changes/changes.xml
>> >     logging/log4j/log4j2/trunk/src/site/xdoc/manual/async.xml
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/FormattedMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/FormattedMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/FormattedMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/FormattedMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -46,12 +46,11 @@ public class FormattedMessage implements
>> >          this.messagePattern = messagePattern;
>> >          this.argArray = arguments;
>> >          this.throwable = throwable;
>> > +        getFormattedMessage(); // LOG4J2-763 take snapshot of parameters 
>> > at message construction time
>> >      }
>> > 
>> >      public FormattedMessage(final String messagePattern, final Object[] 
>> > arguments) {
>> > -        this.messagePattern = messagePattern;
>> > -        this.argArray = arguments;
>> > -        this.throwable = null;
>> > +        this(messagePattern, arguments, null);
>> >      }
>> > 
>> >      /**
>> > @@ -60,9 +59,7 @@ public class FormattedMessage implements
>> >       * @param arg The parameter.
>> >       */
>> >      public FormattedMessage(final String messagePattern, final Object 
>> > arg) {
>> > -        this.messagePattern = messagePattern;
>> > -        this.argArray = new Object[] {arg};
>> > -        this.throwable = null;
>> > +        this(messagePattern, new Object[] {arg}, null);
>> >      }
>> > 
>> >      /**
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/LocalizedMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/LocalizedMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/LocalizedMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/LocalizedMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -78,6 +78,7 @@ public class LocalizedMessage implements
>> >          this.baseName = baseName;
>> >          this.resourceBundle = null;
>> >          this.locale = locale;
>> > +        getFormattedMessage(); // LOG4J2-763 take snapshot of parameters 
>> > at message construction time
>> >      }
>> > 
>> >      public LocalizedMessage(final ResourceBundle bundle, final Locale 
>> > locale, final String key,
>> > @@ -88,6 +89,7 @@ public class LocalizedMessage implements
>> >          this.baseName = null;
>> >          this.resourceBundle = bundle;
>> >          this.locale = locale;
>> > +        getFormattedMessage(); // LOG4J2-763 take snapshot of parameters 
>> > at message construction time
>> >      }
>> > 
>> >      public LocalizedMessage(final Locale locale, final String key, final 
>> > Object[] arguments) {
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MapMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MapMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MapMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MapMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -26,6 +26,11 @@ import org.apache.logging.log4j.util.Str
>> > 
>> > /**
>> >   * Represents a Message that consists of a Map.
>> > + * <p>
>> > + * Thread-safety note: the contents of this message can be modified after 
>> > construction.
>> > + * When using asynchronous loggers and appenders it is not recommended to 
>> > modify this message after the message is
>> > + * logged, because it is undefined whether the logged message string will 
>> > contain the old values or the modified
>> > + * values.
>> >   */
>> > public class MapMessage implements MultiformatMessage {
>> >      /**
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MessageFormatMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MessageFormatMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MessageFormatMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/MessageFormatMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -49,6 +49,7 @@ public class MessageFormatMessage implem
>> >          if (arguments != null && arguments.length > 0 && 
>> > arguments[arguments.length - 1] instanceof Throwable) {
>> >              this.throwable = (Throwable) arguments[arguments.length - 1];
>> >          }
>> > +        getFormattedMessage(); // LOG4J2-763 take snapshot of parameters 
>> > at message construction time
>> >      }
>> > 
>> >      /**
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/ObjectMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/ObjectMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/ObjectMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/ObjectMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -29,6 +29,7 @@ public class ObjectMessage implements Me
>> >      private static final long serialVersionUID = -5903272448334166185L;
>> > 
>> >      private transient Object obj;
>> > +    private final String objectString;
>> > 
>> >      /**
>> >       * Create the ObjectMessage.
>> > @@ -39,6 +40,9 @@ public class ObjectMessage implements Me
>> >              obj = "null";
>> >          }
>> >          this.obj = obj;
>> > +        
>> > +        // LOG4J2-763: take snapshot of parameters at message 
>> > construction time
>> > +        objectString = String.valueOf(obj);
>> >      }
>> > 
>> >      /**
>> > @@ -47,7 +51,7 @@ public class ObjectMessage implements Me
>> >       */
>> >      @Override
>> >      public String getFormattedMessage() {
>> > -        return obj.toString();
>> > +        return objectString;
>> >      }
>> > 
>> >      /**
>> > @@ -56,7 +60,7 @@ public class ObjectMessage implements Me
>> >       */
>> >      @Override
>> >      public String getFormat() {
>> > -        return obj.toString();
>> > +        return objectString;
>> >      }
>> > 
>> >      /**
>> > @@ -89,7 +93,7 @@ public class ObjectMessage implements Me
>> > 
>> >      @Override
>> >      public String toString() {
>> > -        return "ObjectMessage[obj=" + obj.toString() + ']';
>> > +        return "ObjectMessage[obj=" + objectString + ']';
>> >      }
>> > 
>> >      private void writeObject(final ObjectOutputStream out) throws 
>> > IOException {
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StringFormattedMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StringFormattedMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StringFormattedMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StringFormattedMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -48,6 +48,7 @@ public class StringFormattedMessage impl
>> >          if (arguments != null && arguments.length > 0 && 
>> > arguments[arguments.length - 1] instanceof Throwable) {
>> >              this.throwable = (Throwable) arguments[arguments.length - 1];
>> >          }
>> > +        getFormattedMessage(); // LOG4J2-763 take snapshot of parameters 
>> > at message construction time
>> >      }
>> > 
>> >      /**
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -22,6 +22,11 @@ import org.apache.logging.log4j.util.Eng
>> > 
>> > /**
>> >   * Represents a Message that conforms to an RFC 5424 StructuredData 
>> > element along with the syslog message.
>> > + * <p>
>> > + * Thread-safety note: the contents of this message can be modified after 
>> > construction.
>> > + * When using asynchronous loggers and appenders it is not recommended to 
>> > modify this message after the message is
>> > + * logged, because it is undefined whether the logged message string will 
>> > contain the old values or the modified
>> > + * values.
>> >   *
>> >   * @see <a href="https://tools.ietf.org/html/rfc5424";>RFC 5424</a>
>> >   */
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/FormattedMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/FormattedMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/FormattedMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/FormattedMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -83,4 +83,16 @@ public class FormattedMessageTest {
>> >          result = msg.getFormattedMessage();
>> >          assertEquals(testMsg, result);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final String testMsg = "Test message %s";
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        FormattedMessage msg = new FormattedMessage(testMsg, param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "Test message 
>> > abc", actual);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/LocalizedMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/LocalizedMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/LocalizedMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/LocalizedMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -64,4 +64,16 @@ public class LocalizedMessageTest {
>> >          assertEquals("This is test number 1 with string argument Test.", 
>> > msg.getFormattedMessage());
>> >      }
>> > 
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final String testMsg = "Test message %s";
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        LocalizedMessage msg = new LocalizedMessage(testMsg, param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "Test message 
>> > abc", actual);
>> > +    }
>> > +
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MapMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MapMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MapMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MapMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -70,4 +70,22 @@ public class MapMessageTest {
>> >          final String expected = "{message=\"Test message {}\", 
>> > project=\"Log4j\"}";
>> >          assertEquals(expected, result);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testMutableByDesign() { // LOG4J2-763
>> > +        MapMessage msg = new MapMessage();
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        msg.put("key1", "value1");
>> > +        msg.put("key2", "value2");
>> > +        final String result = msg.getFormattedMessage(new 
>> > String[]{"Java"});
>> > +        final String expected = "{key1=\"value1\", key2=\"value2\"}";
>> > +        assertEquals(expected, result);
>> > +
>> > +        // modify parameter after calling msg.getFormattedMessage
>> > +        msg.put("key3", "value3");
>> > +        final String result2 = msg.getFormattedMessage(new 
>> > String[]{"Java"});
>> > +        final String expected2 = "{key1=\"value1\", key2=\"value2\", 
>> > key3=\"value3\"}";
>> > +        assertEquals(expected2, result2);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MessageFormatMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MessageFormatMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MessageFormatMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/MessageFormatMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -61,4 +61,16 @@ public class MessageFormatMessageTest {
>> >          final Throwable t = msg.getThrowable();
>> >          assertNotNull("No Throwable", t);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final String testMsg = "Test message {0}";
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        MessageFormatMessage msg = new MessageFormatMessage(testMsg, 
>> > param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "Test message 
>> > abc", actual);
>> > +    }
>> > }
>> > 
>> > Added: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java?rev=1617051&view=auto
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java
>> >  (added)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -0,0 +1,34 @@
>> > +/*
>> > + * Licensed to the Apache Software Foundation (ASF) under one or more
>> > + * contributor license agreements. See the NOTICE file distributed with
>> > + * this work for additional information regarding copyright ownership.
>> > + * The ASF licenses this file to You 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.apache.logging.log4j.message;
>> > +
>> > +/**
>> > + * Helper class for JUnit tests.
>> > + */
>> > +class Mutable {
>> > +    private String value;
>> > +
>> > +    public Mutable set(String value) {
>> > +        this.value = value;
>> > +        return this;
>> > +    }
>> > +
>> > +    @Override
>> > +    public String toString() {
>> > +        return this.value;
>> > +    }
>> > +}
>> > \ No newline at end of file
>> > 
>> > Propchange: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/Mutable.java
>> > ------------------------------------------------------------------------------
>> >     svn:eol-style = native
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ObjectMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ObjectMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ObjectMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ObjectMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -39,4 +39,15 @@ public class ObjectMessageTest {
>> >          final String result = msg.getFormattedMessage();
>> >          assertEquals(testMsg, result);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        ObjectMessage msg = new ObjectMessage(param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "abc", actual);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ParameterizedMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ParameterizedMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ParameterizedMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ParameterizedMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -36,4 +36,16 @@ public class ParameterizedMessageTest {
>> >          result = msg.getFormattedMessage();
>> >          assertEquals(testMsg, result);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final String testMsg = "Test message {}";
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        ParameterizedMessage msg = new ParameterizedMessage(testMsg, 
>> > param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "Test message 
>> > abc", actual);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StringFormattedMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StringFormattedMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StringFormattedMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StringFormattedMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -60,4 +60,16 @@ public class StringFormattedMessageTest 
>> >          final Throwable t = msg.getThrowable();
>> >          assertNotNull("No Throwable", t);
>> >      }
>> > +
>> > +    @Test
>> > +    public void testSafeWithMutableParams() { // LOG4J2-763
>> > +        final String testMsg = "Test message %s";
>> > +        final Mutable param = new Mutable().set("abc");
>> > +        StringFormattedMessage msg = new StringFormattedMessage(testMsg, 
>> > param);
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        param.set("XYZ");
>> > +        String actual = msg.getFormattedMessage();
>> > +        assertEquals("Should use initial param value", "Test message 
>> > abc", actual);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -43,4 +43,23 @@ public class StructuredDataMessageTest {
>> >          final StructuredDataMessage msg = new 
>> > StructuredDataMessage("MsgId@12345", testMsg, "Alert");
>> >          msg.put("This is a very long key that will violate the key length 
>> > validation", "Testing");
>> >      }
>> > +
>> > +    @Test
>> > +    public void testMutableByDesign() { // LOG4J2-763
>> > +        final String testMsg = "Test message {}";
>> > +        StructuredDataMessage msg = new StructuredDataMessage("MsgId@1", 
>> > testMsg, "Alert");
>> > +
>> > +        // modify parameter before calling msg.getFormattedMessage
>> > +        msg.put("message", testMsg);
>> > +        msg.put("project", "Log4j");
>> > +        final String result = msg.getFormattedMessage();
>> > +        final String expected = "Alert [MsgId@1 message=\"Test message 
>> > {}\" project=\"Log4j\"] Test message {}";
>> > +        assertEquals(expected, result);
>> > +
>> > +        // modify parameter after calling msg.getFormattedMessage
>> > +        msg.put("memo", "Added later");
>> > +        final String result2 = msg.getFormattedMessage();
>> > +        final String expected2 = "Alert [MsgId@1 memo=\"Added later\" 
>> > message=\"Test message {}\" project=\"Log4j\"] Test message {}";
>> > +        assertEquals(expected2, result2);
>> > +    }
>> > }
>> > 
>> > Modified: 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ThreadDumpMessageTest.java
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ThreadDumpMessageTest.java?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ThreadDumpMessageTest.java
>> >  (original)
>> > +++ 
>> > logging/log4j/log4j2/trunk/log4j-api/src/test/java/org/apache/logging/log4j/message/ThreadDumpMessageTest.java
>> >  Sun Aug 10 06:40:14 2014
>> > @@ -73,6 +73,22 @@ public class ThreadDumpMessageTest {
>> >          assertEquals(expected, msg.toString());
>> >      }
>> > 
>> > +    @Test
>> > +    public void testUseConstructorThread() throws InterruptedException { 
>> > // LOG4J2-763
>> > +        final ThreadDumpMessage msg = new ThreadDumpMessage("Test");
>> > +
>> > +        final String[] actual = new String[1];
>> > +        Thread other = new Thread("OtherThread") {
>> > +            public void run() {
>> > +                actual[0] = msg.getFormattedMessage();
>> > +            }
>> > +        };
>> > +        other.start();
>> > +        other.join();
>> > +        
>> > +        assertTrue("No mention of other thread in msg", 
>> > !actual[0].contains("OtherThread"));
>> > +    }
>> > +
>> >      private class Thread1 extends Thread {
>> >          private final ReentrantLock lock;
>> > 
>> > 
>> > Modified: logging/log4j/log4j2/trunk/src/changes/changes.xml
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/src/changes/changes.xml?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- logging/log4j/log4j2/trunk/src/changes/changes.xml (original)
>> > +++ logging/log4j/log4j2/trunk/src/changes/changes.xml Sun Aug 10 06:40:14 
>> > 2014
>> > @@ -22,6 +22,12 @@
>> >    </properties>
>> >    <body>
>> >      <release version="2.0.2" date="2014-0?-??" description="Bug fixes and 
>> > enhancements">
>> > +      <action issue="LOG4J2-763" dev="rpopma" type="fix">
>> > +        Improved FormattedMessage, StringFormattedMessage, 
>> > LocalizedMessage, MessageFormatMessage and
>> > +        ObjectMessage for asynchronous logging to ensure the formatted 
>> > message does not change even if
>> > +        parameters are modified by the application. (ParameterizedMessage 
>> > was already safe.)
>> > +        Improved documentation.
>> > +      </action>      
>> >        <action issue="LOG4J2-729" dev="rpopma" type="fix">
>> >          Emit warning message to console if no configuration file found.
>> >        </action>      
>> > 
>> > Modified: logging/log4j/log4j2/trunk/src/site/xdoc/manual/async.xml
>> > URL: 
>> > http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/src/site/xdoc/manual/async.xml?rev=1617051&r1=1617050&r2=1617051&view=diff
>> > ==============================================================================
>> > --- logging/log4j/log4j2/trunk/src/site/xdoc/manual/async.xml (original)
>> > +++ logging/log4j/log4j2/trunk/src/site/xdoc/manual/async.xml Sun Aug 10 
>> > 06:40:14 2014
>> > @@ -124,6 +124,26 @@
>> > logging in addition to synchronous
>> > logging for the audit trail.)
>> > </li>
>> > +   <li>In some rare cases, care must be taken with mutable messages.
>> > +     Most of the time you don't need to worry about this. Log4 will 
>> > ensure that log messages like 
>> > +     <code>logger.debug("My object is {}", myObject)</code> will use the 
>> > state of the
>> > +     <code>myObject</code> parameter at the time of the call to 
>> > <code>logger.debug()</code>.
>> > +     The log message will not change even if <code>myObject</code> is 
>> > modified later.
>> > +     It is safe to asynchronously log mutable objects because most 
>> > +     <a 
>> > href="../log4j-api/apidocs/org/apache/logging/log4j/message/Message.html">Message</a>
>> > +     implementations built-in to Log4j take a snapshot of the parameters.
>> > +     There are some exceptions however: 
>> > +     <a 
>> > href="../log4j-api/apidocs/org/apache/logging/log4j/message/MapMessage.html">MapMessage</a>
>> > +     and
>> > +     <a 
>> > href="../log4j-api/apidocs/org/apache/logging/log4j/message/StructuredDataMessage.html">StructuredDataMessage</a>
>> > +     are mutable by design: fields can be added to these messages after 
>> > the message object was created.
>> > +     These messages should not be modified after they are logged with 
>> > asynchronous loggers or
>> > +     asynchronous appenders; you may or may not see the modifications in 
>> > the resulting log output.
>> > +     Similarly, custom  
>> > +     <a 
>> > href="../log4j-api/apidocs/org/apache/logging/log4j/message/Message.html">Message</a>
>> > +     implementations should be designed with asynchronous use in mind, 
>> > and either take a snapshot
>> > +     of their parameters at construction time, or document their 
>> > thread-safety characteristics.
>> > +   </li>
>> > </ul>
>> > </subsection>
>> > <a name="AllAsync" />
>> > 
>> > 
>> 
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: [email protected]
>> For additional commands, e-mail: [email protected]

Reply via email to