Tuesday, November 14, 2006

log4j and PeopleCode Part II

Last month I wrote about using log4j to debug PeopleCode. This is a tool that I use quite often. Here are a couple more hints to help you use log4j from PeopleCode.

One of the main benefits of log4j is the ability to configure, and reconfigure, log4j without modifying your code. However, sometimes a configuration file is not practical. Here is an example of configuring log4j from PeopleCode:
Local JavaObject &logger = GetJavaClass("org.apache.log4j.Logger").getLogger("my.custom.logger");
Local JavaObject &layout = CreateJavaObject("org.apache.log4j.PatternLayout", "%-4r %d [%t] %-5p %c [%x] - %m%n");
Local JavaObject &appender = CreateJavaObject("org.apache.log4j.ConsoleAppender", &layout);


&logger.debug("Hello from a PeopleCode configured logger.");

Running this code on the AppServer will write log messages to the AppServer's stdout file. log4j has several other appenders that may be more practical if the AppServer's stdout file is not accessible. Here is a configuration example that uses the SMTPAppender to send log messages to an e-mail address (preferrably your e-mail address).
Local JavaObject &logger = GetJavaClass("org.apache.log4j.Logger").getLogger("jjm.email.debugger");
Local JavaObject &layout = CreateJavaObject("org.apache.log4j.HTMLLayout");
Local JavaObject &appender = CreateJavaObject("org.apache.log4j.net.SMTPAppender");

&appender.setSubject("PeopleCode debug log");


&logger.fatal("Hello from PeopleCode!");

One thing to note about the SMTPAppender is that it only sends error and fatal log messages to the specified e-mail address.

About error messages... As you know, error is a key word in PeopleCode. Therefore, it is not possible to execute the error method of the Logger object directly. However, you may be able to get around this by using Java's reflection to execute the method.