BYR Achieve · 镜像论坛

统计函数运行时间时遇到的一个问题

2016/3/5镜像同步3 回复

有个函数怀疑比较耗时，就拿出来测了测测试代码如下 while( (line=br.readLine())!=null) { //System.out.println(line); //executors.execute(new Handler(line)); //Thread.currentThread().sleep(100); x++; if(line.length() > 20000) { //System.out.println(line); long start = System.nanoTime(); String tt = replacePwd(line); long end = System.nanoTime(); System.out.println(line.length()+" " +(end-start)/1000000); } } 要测试的函数如下： public static String replacePwd(String log) { String key = "(\\\\?)(\"?)(=|:)[^,^}]*(}|,)"; String value = "$2$3$1$2$1$2$4"; int length = getPASSWORDVALUELength(log,"PASSWORDVALUE");// 获取密码长度 int transferKeyLength = getPASSWORDVALUELength(log,"transferKey");// 获取密码长度 // -------------------add map toStirng replace password------------- log = log.replaceAll("Password"+key, "Password"+value); log = log.replaceAll("password"+key, "password"+value); log = log.replaceAll("newPassword"+key, "newPassword"+value); log = log.replaceAll("encryptPassword"+key, "encryptPassword"+value); log = log.replaceAll("PSWD"+key, "PSWD"+value); log = log.replaceAll("Passwd"+key, "Passwd"+value); log = log.replaceAll("pinData"+key, "pinData"+value); log = log.replaceAll("PinBlock"+key, "PinBlock"+value); log = log.replaceAll("encryptPasswordOld"+key, "encryptPasswordOld"+value); log = log.replaceAll("encryptPasswordNew"+key, "encryptPasswordNew"+value); log = log.replaceAll("AuthPwd"+key, "AuthPwd"+value);// log = log.replaceAll("SIGN_PWD"+key, "SIGN_PWD"+value); log = log.replaceAll("\\SIGN_PWD"+key, "SIGN_PWD"+value); log = log.replaceAll("PASSWORDVALUE"+key, "PASSWORDVALUE$1$2$3$1$2"+length+"$1$2$4");// log = log.replaceAll("NEWPASSWORDVALUE"+key, "NEWPASSWORDVALUE"+value); log = log.replaceAll("sqPwd"+key, "sqPwd"+value);// log = log.replaceAll("draweeVoucherPwd"+key, "draweeVoucherPwd"+value);// log = log.replaceAll("transferKey"+key, "transferKey$1$2$3$1$2"+transferKeyLength+"$1$2$4");// log = log.replaceAll("plainpin"+key, "plainpin"+value); log = log.replaceAll("cvv2"+key, "cvv2"+value); log = log.replaceAll("cvn2"+key, "cvn2"+value); log = log.replaceAll("cardValidityDate"+key, "cardValidityDate"+value); log = log.replaceAll("useLife"+key, "useLife"+value); return replacePwdFormXMl(log); } private static int getPASSWORDVALUELength(String log,String key) { int length=0; try { String findKey = "[\\\\]?[\"]?[=|:]{1}[\\\\]?[\"]?([^\"^ ^,]*)[\\\\]?[\"]?(,|\\})"; Pattern p = Pattern.compile(key + findKey); Matcher m = p.matcher(log); String pwd = ""; if (m.find()) { pwd = m.group(1); length = pwd.length(); } } catch (Exception e) { } return length; } public static String replacePwdFormXMl(String log) { log = log.replaceAll("<Password>.*</Password>", "<Password></Password>"); log = log.replaceAll("<FundTransPwd>.*</FundTransPwd>", "<FundTransPwd></FundTransPwd>"); log = log.replaceAll("<MobilePasswd>.*</MobilePasswd>", "<MobilePasswd></MobilePasswd>"); log = log.replaceAll("<PinBlock>.*</PinBlock>", "<PinBlock></PinBlock>"); return log; } 运行的结果如下： start measuring...2016-03-05 21:55:07.708 20700 14 20182 4 20687 4 20178 1 26793 1 21062 1 33375 1 26776 1 27455 1 20166 0 20166 0 20682 1 20681 1 20171 0 30836 1 20171 0 31203 1 20171 0 35210 1 47846 1 20170 1 23483 1 20680 0 20170 0 22790 0 每次都是前几次比较慢，而且是逐渐变快，如果是第一次运行需要加载一些东西，应该是第一次后就都基本一样了，是不是因为用了JIT？我主要是怀疑这个函数处理近50000字符的字符串只要1ms，机器是2.0GHz点i7,8G 1600 DDR3内存。

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