测试字符串替换速度

private static String escape(String input, char[] escapeChar,StringBuilder buffer) {buffer.setLength(0);for (int i = 0; i < input.length(); i++) {char c = input.charAt(i);for (int j = 0; j < escapeChar.length; j++) {if (escapeChar[j] == c) {buffer.append('//');break;}}buffer.append(c);}return buffer.toString();}private static void batchTest(Callable<String>... tests) {for (Callable<String> callable : tests) {long st = System.currentTimeMillis();for (int i = 0; i < 100000; i++) {try {callable.call();} catch (Exception e) {e.printStackTrace();}}System.out.println(System.currentTimeMillis() - st);try {System.out.println("result=" + callable.call());} catch (Exception e) {e.printStackTrace();}}}@SuppressWarnings("unchecked")public static void main(String[] args) {final StringBuilder buf = new StringBuilder();final String s = "asdf[c1|c2]sd[c3]sdf[c4]";batchTest(new Callable<String>() {public String call() throws Exception {return s.replace("[", "//[").replace("]", "//]").replace("|","//|");}}, new Callable<String>() {public String call() throws Exception {return s.replaceAll("//[|//]|//|", "////$0");}}, new Callable<String>() {public String call() throws Exception {return escape(s, new char[] { '[', ']', '|' }, buf);}}, new Callable<String>() {public String call() throws Exception {return StringUtils.replaceEach(s,new String[] { "[", "]", "|" }, new String[] { "//[","//]", "//|" });}});}

 

测试结果：

1047
result=asdf/[c1/|c2/]sd/[c3/]sdf/[c4/]
891
result=asdf/[c1/|c2/]sd/[c3/]sdf/[c4/]
78
result=asdf/[c1/|c2/]sd/[c3/]sdf/[c4/]
578
result=asdf/[c1/|c2/]sd/[c3/]sdf/[c4/]
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现象：replaceAll的效率在多个频繁替换下还是可以用的，但是如果真的很多的话，不会有人不断的replace().replace()...这样吧；

再看正则和apache stringutil的replace相比又慢了许多；

结论：对于替换多个字符串的话，推荐使用apache的stringutil来替换字符串，如果是转义字符串的话还是自己写吧~哈哈