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/]
--------------------------------------------------

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