仿log4j 写 log 代码

log4j 一直有个问题无法满足我，有可能我还不知道怎么去使用它。

就是他会把项目中所有的日志信息都记到一个文件里面，而业务系统往往需要根据某个业务流程查看日志分析。

public class BusinessLogUtil {  
    public enum Level {
        ERROR(40, "ERROR"),
        WARN(30, "WARN"),
        INFO(20, "INFO"),
        DEBUG(10, "DEBUG"),
        TRACE(0, "TRACE");

        private int levelInt;
        private String levelStr;

        private Level(int i, String s) {
            this.levelInt = i;
            this.levelStr = s;
        }

        public int toInt() {
            return this.levelInt;
        }

        @Override
        public String toString() {
            return this.levelStr;
        }
    }

    /**
     * 得到记录日志所有的文件：行号
     *
     * @return
     */
    private static String getLineInfo() {
        StackTraceElement ste = new Throwable().getStackTrace()[3];
        return MessageFormat.format("[{0}:{1}]", ste.getClassName(), ste.getLineNumber());
    }

    /**
     * 记录日志信息
     *
     * @param businessName
     * @param content
     */
    private void write(String businessName, Level logLevel, String content) {
        String logKey = businessName;
        if (logKey.contains("_")) {
            logKey = logKey.split("_")[0];
        }
        boolean isContinue = true; //TODO 此处根据 businessName 去数据库里面看这个业务日志有没有要求开启
        if (!isContinue) {
            //如果Elb_Settings 没开启开关，则不记录日志
            return;
        }
        FileOutputStream out = null;
        BufferedOutputStream Buff = null;
        try {
            Date currentDate = new Date();
            String logRoot = System.getProperty("catalina.home");
            if (StringUtil.isNullOrEmpty(logRoot)) {
                logRoot = "";
            }
            String fileName = logRoot + "/logs/" + businessName + "_" + logLevel.levelStr.toLowerCase() + "." + com.iron.fast.util.DateUtil.toFormatString("yyyy-MM-dd", currentDate) + ".log";
            out = new FileOutputStream(fileName, true);
            Buff = new BufferedOutputStream(out);
            String msg = MessageFormat.format("{0} {1} {2} - {3}
", DateUtil.toFormatString("yyyy-MM-dd HH:mm:ss", currentDate), logLevel.levelStr, getLineInfo(), content);
            Buff.write(msg.getBytes("utf-8"));
            Buff.flush();
            Buff.close();
        } catch (Exception var15) {
            var15.printStackTrace();
        } finally {
            try {
                Buff.close();
                out.close();
            } catch (Exception var14) {
                var14.printStackTrace();
            }
        }
    }

    /**
     * 业务日志
     *
     * @param businessName
     * @param content
     */
    public void info(String businessName, String content) {
        write(businessName, Level.INFO, content);
    }

    /**
     * 警告日志，同时也会记录到 info 中
     *
     * @param businessName
     * @param content
     */
    public void warn(String businessName, String content) {
        write(businessName, Level.WARN, content);
        write(businessName, Level.WARN, content);
    }

    /**
     * 错误日志，同时也会记录到 info 中，warn 中不记
     *
     * @param businessName
     * @param content
     */
    public void error(String businessName, String content) {
        write(businessName, Level.ERROR, content);
        write(businessName, Level.ERROR, content);
    } 
}