[LOG4J2-1502] CsvParameterLayout and CsvLogEventLayout insert NUL character if data starts with {, (, [ or "

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.2
• Fix Version/s: 2.7
• Component/s: Layouts
• External issue URL: http://stackoverflow.com/questions/38784961/csvparameterlayout-in-log4j2-is-inserting-nul-character-if-data-starts-and-ends/38798829#38798829
• Assignee: Unassigned
• Reporter: Sumit Singhal
• Created: 08/Aug/16 09:18
• Updated: 29/Aug/16 19:45
• Resolved: 29/Aug/16 19:45

Description

I am using CsvParameterLayout to generate a CSV file out of log4j2. One of the column is a JSON string. Following is the logger method I am using:

logger.info("log:{}",json);

Following is the JSON string:

{"id":10,"name":"sumit"}

And following is the string which is getting printed in CSV output file:

NUL

{"id":10,"name":"sumit"}

NUL

The NUL character is the \x00 character. When I open the file in notepad++, then only this character appears. In notepad it shows as space. This poses a problem in CSV processing module.

If there is some alphabet before {, then the output in CSV is fine. It seems as if log4j is escaping '{' with a NUL character. It is happening if the string starts with

{, (, [, ' or ". Following are the dependencies: {code:xml}

<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.6.2</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.6.2</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-csv</artifactId>
<version>1.4</version>
</dependency>

Issue Links

• requires: LOG4J2-905 Ability to disable (date) lookup completely, compatibility issues with other libraries like Camel