如何实现服务器启动自动创建日志

有时候我们的服务是以SDK的方式提供给外围使用。如果SDK需要打印业务日志进行排查的话，需要业务使用方配置log4j，这样使用起来相当不友好。而且很容易忽略这一块的配置，导致上线之后务日志可进行排查。

比如我们使用的中间件zdal， 会自动在服务器打印一下日志，无需我们感知。

我们可以通过log4j 的API方式实现服务启动自动创建监控日志：

/**
* Alipay.com Inc.
* Copyright (c) 2004-2015 All Rights Reserved.
*/
package com.alipay.ap.prodintl.common.log;

import java.io.File;
import java.io.IOException;

import org.apache.log4j.Appender;
import org.apache.log4j.DailyRollingFileAppender;
import org.apache.log4j.Level;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.apache.log4j.PatternLayout;
import org.apache.log4j.spi.LoggerRepository;
import org.springframework.beans.factory.InitializingBean;

/**
* SDK客户端日志配置
*
* @author baoxing.gbx
* @version $Id: ClientLogger.java, v 0.1 2015年7月30日 下午9:05:57 baoxing.gbx Exp $
*/
public class ClientLogger implements InitializingBean {

/** 系统SAL层(调用外部系统服务)摘要日志 */
public static final Logger  APPRODINTL_SAL_DIGEST     = Logger
.getLogger(LoggerNames.APPRODINTL_SAL_DIGEST);

/** 系统SERVICE层(外围系统调用本系统服务)摘要日志 */
public static final Logger  APPRODINTL_SERVICE_DIGEST = Logger
.getLogger(LoggerNames.APPRODINTL_SERVICE_DIGEST);

/** 系统业务日志 */
public static final Logger  APPRODINTL_BUSINESS       = Logger
.getLogger(LoggerNames.APPRODINTL_BUSINESS);

/** 错误APPENDER */
private static final String ERROR_APPENDER            = "ERROR-APPENDER";

/** 控制台的appender */
private static final String CONSOLE_APPENDER          = "CONSOLE";

private static final String LogPath                   = "logs";

/** 应用名称 */
private String              appName;

/** 日志级别  */
private String              logLevel;

/** 分隔符 */
public final static String  SEPARATOR                 = ",";

/** 日志参数 */
public final static String  DAY_DATE_PATTERN          = "'.'yyyy-MM-dd";
public final static String  DAY_DATE_DIAGEST_PATTERN  = "'.'yyyy-MM-dd_HH";
public final static String  LAYOUT_PATTERN            = "%d [%t] - %m%n";
public final static String  DAILY_APPENDER_NAME       = "_DAILY_APPENDER_NAME";
public final static String  CONVERSION_PATTERN        = "%d %-5p %m%n";

/**
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
@Override
public void afterPropertiesSet() throws Exception {

initLog(LoggerNames.APPRODINTL_SERVICE_DIGEST_NAME, APPRODINTL_SERVICE_DIGEST);

initLog(LoggerNames.APPRODINTL_SAL_DIGEST_NAME, APPRODINTL_SAL_DIGEST);

initLog(LoggerNames.APPRODINTL_BUSINESS_NAME, APPRODINTL_BUSINESS);
}

/**
* 初始化Appender并关联到对应Logger
*
* @param logFileName
*          日志文件名称
* @param logger
*          Logger
*/
private void initLog(String logFileName, Logger logger) {

LoggerRepository repository = LogManager.getLoggerRepository();
//初始化错误日志appender
DailyRollingFileAppender errorAppender = getErrorAppender(repository);
//初始化监控日志appender
DailyRollingFileAppender monitorAppender = getMonitorAppender(repository, logFileName);
//初始化控制台日志appender
Appender consoleAppender = getConsoleAppender(repository);
// 获取日志级别
logger.setLevel(Level.toLevel(this.logLevel));
if (monitorAppender != null) {
logger.addAppender(monitorAppender);
logger.addAppender(errorAppender);
}

//如果控制台的appender配置，添加
if (consoleAppender != null) {
logger.addAppender(consoleAppender);
}
logger.setAdditivity(false);

}

/**
* 获取错误日志appender
*
* @param repository
* @return
*/
private Appender getConsoleAppender(LoggerRepository repository) {
return repository.getRootLogger().getAppender(CONSOLE_APPENDER);
}

/**
* 获取监控日志appender
*
* @param repository
* @param logFileName
* @return
*/
private DailyRollingFileAppender getMonitorAppender(LoggerRepository repository,
String logFileName) {
PatternLayout layout = new PatternLayout(LAYOUT_PATTERN);
layout.setConversionPattern(CONVERSION_PATTERN);
DailyRollingFileAppender monitorAppender = null;
//日志文件目录
String path = getLogFilePath();
File dir = new File(path);
if (!dir.exists()) {
dir.mkdirs();
}
//完整日志文件路径
String fullLogFileName = path + logFileName;
try {
// 文件
String rollingDatePattern = DAY_DATE_PATTERN;
monitorAppender = new DailyRollingFileAppender(layout, fullLogFileName,
rollingDatePattern);
monitorAppender.setAppend(true);
monitorAppender.setEncoding("UTF-8");
monitorAppender.setName(DAILY_APPENDER_NAME);

} catch (IOException e) {

throw new RuntimeException(e);
}
return monitorAppender;
}

/**
* 获取控制台日志appender
*
* @param repository
* @return
*/
private DailyRollingFileAppender getErrorAppender(LoggerRepository repository) {
return (DailyRollingFileAppender) repository.getRootLogger().getAppender(ERROR_APPENDER);
}

/**
* 构造日志文件目录
*
* @return 日志文件目录
*/
private String getLogFilePath() {

String userHome = System.getProperty("user.home");
if (!userHome.endsWith(File.separator)) {
userHome += File.separator;
}
return userHome + LogPath + File.separator + this.appName + File.separator;
}

/**
* Setter method for property <tt>appName</tt>.
*
* @param appName value to be assigned to property appName
*/
public void setAppName(String appName) {
this.appName = appName;
}

/**
* Setter method for property <tt>logLevel</tt>.
*
* @param logLevel value to be assigned to property logLevel
*/
public void setLogLevel(String logLevel) {
this.logLevel = logLevel;
}

}