本文实例讲述了PHP日志LOG类定义与用法。分享给大家供大家参考，具体如下：

/**

* PHP log 类

*/

class Config{

public static function getConfig (){

return array(

'LOG_FILE'=>'test.txt',

'LOG_LEVEL'=>75 //INFO

);

}

}

class Log{

private $LogFile;

private $logLevel;

const DEBUG = 100;

const INFO = 75;

const NOTICE = 50;

const WARNING =25;

const ERROR = 10;

const CRITICAL = 5;

private function __construct(){

$cfg = Config::getConfig();

$this->logLevel = isset($cfg['LOG_LEVEL']) ? $cfg['LOG_LEVEL']:LOG::INFO;

if(!isset($cfg['LOG_FILE']) && strlen($cfg['LOG_FILE'])){

throw new Exception('can\'t set file to empty');

}

$this->LogFile = @fopen($cfg['LOG_FILE'],'a+');

if(!is_resource($this->LogFile)){

throw new Exception('invalid file Stream');

}

}

public static function getInstance(){

static $obj;

if(!isset($obj)){

$obj = new Log();

}

return $obj;

}

public function LogMessage($msg, $logLevel = Log::INFO,$module = null){

if($logLevel > $this->logLevel){

return ;

}

date_default_timezone_set('Asia/shanghai');

$time = strftime('%x %X',time());

$msg = str_replace("\t",'',$msg);

$msg = str_replace("\n",'',$msg);

$strLogLevel = $this->levelToString($logLevel);

if(isset($module)){

$module = str_replace(array("\n","\t"),array("",""),$module);

}

$logLine = "$time\t$msg\t$strLogLevel\t$module\r\n";

fwrite($this->LogFile,$logLine);

}

public function levelToString($logLevel){

$ret = '[unknow]';

switch ($logLevel){

case LOG::DEBUG:

$ret = 'LOG::DEBUG';

break;

case LOG::INFO:

$ret = 'LOG::INFO';

break;

case LOG::NOTICE:

$ret = 'LOG::NOTICE';

break;

case LOG::WARNING:

$ret = 'LOG::WARNING';

break;

case LOG::ERROR:

$ret = 'LOG::ERROR';

break;

case LOG::CRITICAL:

$ret = 'LOG::CRITICAL';

break;

}

return $ret;

}

}

$logIns = LOG::getInstance();

//print_r($logIns);

$logIns->logMessage("test",LOG::INFO,'myTest');

?>

运行程序，在当前目录下生成test.txt文件内容如下(这里是运行3次的结果)：

09/06/18  14:56:20 test LOG::INFO myTest

09/06/18  14:56:21 test LOG::INFO myTest

09/06/18  14:56:22 test LOG::INFO myTest

希望本文所述对大家PHP程序设计有所帮助。