操作log4jAPI

import java.io.ByteArrayOutputStream;
import java.io.PrintWriter;
import org.apache.log4j.*;

public class CustomerLogUtil
{

    private static CustomerLogUtillogUtil;
    private Logger log;

    public static SOALogUtil getInstance(Class c)
    {
        if(logUtil == null)
        {
            logUtil = new CustomerLogUtil(c);
        }
        return logUtil;
    }

    private CustomerLogUtil(Class c)
    {
        String filepath = (new StringBuilder()).append(System.getProperty("java.classpath")).append("/config/log4j.properties").toString();
        PropertyConfigurator.configure(filepath);
        log = Logger.getLogger(c);
        Logger _tmp = log;
        RollingFileAppender appender = (RollingFileAppender)Logger.getRootLogger().getAppender("stdout");
        String file = appender.getFile().replace("CustomerLogUtil.log", (new StringBuilder()).append(c.getSimpleName()).append(".log").toString());
        appender.setFile(file);
        appender.activateOptions();
    }

    private String objToString(Object obj)
    {
        if(obj instanceof Exception)
        {
            if(((Exception)obj).getStackTrace() == null)
            {
                ByteArrayOutputStream buf = new ByteArrayOutputStream();
                ((Exception)obj).printStackTrace(new PrintWriter(new PrintWriter(buf, true)));
                return buf.toString();
            } else
            {
                return ((Exception)obj).getMessage();
            }
        } else
        {
            return obj.toString();
        }
    }

    public void info(Object obj)
    {
        log.info(objToString(obj));
    }

    public void debug(Object obj)
    {
        log.debug(objToString(obj));
    }

    public void error(Object obj)
    {
        log.error(objToString(obj));
    }

    public void fatal(Object obj)
    {
        log.fatal(objToString(obj));
    }

    public void warn(Object obj)
    {
        log.warn(objToString(obj));
    }
}

 

log4j.properties:

log4j.rootLogger=info, stdout

log4j.appender.stdout=org.apache.log4j.RollingFileAppender

log4j.appender.stdout.Threshold=info

log4j.appender.stdout.File = ${java.classpath}/log/CustomerLogUtil.log

log4j.appender.stdout.MaxFileSize=100MB

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.MaxBackupIndex=1

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%d %c %n%-5p %c %x - %m%n