I have a log4j.xml config file. and a RollingFileAppender to which I need to provide file path for storing logs. The problem is my code will be deployed on Unix machine as a runnable jar. So if I pass parameter something like this:
value=logs/messages.log"
it creates folder named logs inside my HOME directory and writes all the messages to file inside this directory.
I have a environmental variable set to some value. I want to use path of that variable and write messages under that path. How can I achieve it?
I had tried using this:
value="${MY_HOME}/logs/message.log"
but this does not work. Can anyone suggest a solution for this problem?
This question is related to
java
log4j
environment-variables
When parsing its configuration file, the expression ${MY_HOME} will be expanded to the value of the system property named MY_HOME, not the system environment variable. There's a difference between the two.
To achieve this in a clean way, you'll have to add something like this to the JVM invocation line:
-DMY_HOME=$MY_HOME
That would define the Java system property MY_HOME to contain the value of the environment variable MY_HOME.
This syntax is documented only in log4j 2.X so make sure you are using the correct version.
<Appenders>
<File name="file" fileName="${env:LOG_PATH}">
<PatternLayout>
<Pattern>%d %p %c{1.} [%t] %m %ex%n</Pattern>
</PatternLayout>
</File>
</Appenders>
http://logging.apache.org/log4j/2.x/manual/lookups.html#EnvironmentLookup
Maybe... :
datestamp=yyyy-MM-dd/HH:mm:ss.SSS/zzz
layout=%d{${datestamp}} ms=%-4r [%t] %-5p %l %n%m %n%n
# infoFile
log4j.appender.infoFile=org.apache.log4j.RollingFileAppender
log4j.appender.infoFile.File=${MY_HOME}/logs/message.log
log4j.appender.infoFile.layout=org.apache.log4j.PatternLayout
log4j.appender.infoFile.layout.ConversionPattern=${layout}
To dynamically change a variable you can do something like this:
String value = System.getenv("MY_HOME");
Properties prop = new Properties("log4j.properties");
prop.put("MY_HOME", value); // overwrite with value from environment
PropertyConfigurator.configure(prop);
you CAN give it environment variables. Just preppend env: before the variable name, like this:
value="${env:MY_HOME}/logs/message.log"
I got this working.
log4j.appender.file.File=${LogFilePath}
-DLogFilePath=C:\work\MyLogFile.log
Since you are using unix you can use a path like this.
/home/Production/modulename/logs/message.log
path should start with /
Log4j entry
#- File to log to and log format
log4j.appender.file.File=${LOG_PATH}/mylogfile.log
Java program
String log4jConfPath = "path/log4j.properties";
File log4jFile = new File(log4jConfPath);
if (log4jFile.exists()) {
System.setProperty("LOG_PATH", "c:/temp/");
PropertyConfigurator.configure(log4jFile.getAbsolutePath());
logger.trace("test123");
}
java -DLOG_DIR=${LOG_DIR} -jar myjar.jar "param1" "param2" ==> in cmd line if you have "value="${LOG_DIR}/log/clientProject/project-error.log" in xml
Source: Stackoverflow.com