仿log4j 寫 log 代碼

log4j 一直有個問題沒法知足我，有可能我還不知道怎麼去使用它。

就是他會把項目中全部的日誌信息都記到一個文件裏面，而業務系統每每須要根據某個業務流程查看日誌分析。

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;
        }
    }

    /**
     * 獲得記錄日誌全部的文件：行號
     *
     * @return
     */
    private static String getLineInfo() {
        StackTraceElement ste = new Throwable().getStackTrace()[3];
        return MessageFormat.format("[{0}:{1}]", ste.getClassName(), ste.getLineNumber());
    }

    /**
     * 記錄日誌信息
     *
     * @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 此處根據 businessName 去數據庫裏面看這個業務日誌有沒有要求開啓
        if (!isContinue) {
            //若是Elb_Settings 沒開啓開關，則不記錄日誌
            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}\r\n", 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();
            }
        }
    }

    /**
     * 業務日誌
     *
     * @param businessName
     * @param content
     */
    public void info(String businessName, String content) {
        write(businessName, Level.INFO, content);
    }

    /**
     * 警告日誌，同時也會記錄到 info 中
     *
     * @param businessName
     * @param content
     */
    public void warn(String businessName, String content) {
        write(businessName, Level.WARN, content);
        write(businessName, Level.WARN, content);
    }

    /**
     * 錯誤日誌，同時也會記錄到 info 中，warn 中不記
     *
     * @param businessName
     * @param content
     */
    public void error(String businessName, String content) {
        write(businessName, Level.ERROR, content);
        write(businessName, Level.ERROR, content);
    } 
}