After I joined in new project, I realized log is very important. We can log in console or file. Here is to introduce a way to log in file without overwrite. It's really easy to use log4j.
# Define the root logger with appender file
log4j.rootLogger = DEBUG, FILE
# Define the file appender
log4j.appender.FILE=org.apache.log4j.rolling.RollingFileAppender
# Set the name of the file
log4j.appender.FILE.rollingPolicy = org.apache.log4j.rolling.TimeBasedRollingPolicy
log4j.appender.FILE.rollingPolicy.FileNamePattern = tweetError.%d{MM-dd-yyyy}.log
#log4j.appender.FILE.File=tweeterror.log
# Set the immediate flush to true (default)
log4j.appender.FILE.ImmediateFlush=true
# Set the threshold to debug mode
log4j.appender.FILE.Threshold=info
# Set the append to false, overwrite
log4j.appender.FILE.Append=true
# Define the layout for file appender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%m%n
What you need to do is to copy the code in a log4j.propeties file and add log4j.jar into your project. Then you'll see it'll create a new file every day when error is logged.