Does log4j support JSON format?

Question

Is it possible to let log4j output its logging in JSON format by only altering the log4j.properties.xml configuration file?
I make use of an old application tha

Answer 1

just use buildin PatternLayout is ok:

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.encoding=UTF-8
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern={"debug_level":"%p","debug_timestamp":"%d{ISO8601}","debug_thread":"%t","debug_file":"%F", "debug_line":"%L","debug_message":"%m"}%n

will out put like:

{
    "debug_level" : "INFO",
    "debug_timestamp" : "2016-05-26 16:37:08,938",
    "debug_thread" : "main",
    "debug_file" : "TestLogOutPut.java",
    "debug_line" : "316",
    "debug_message" : "hello i am a log message"
}