Java String.replaceAll 正则表达式

Question

我想替换

的第一个上下文

web/style/clients.html

使用 java String.replaceFirst 方法，我可以获得:

${pageContext.request.contextPath}/style/clients.html

我试过了

String test =  "web/style/clients.html".replaceFirst("^.*?/", "hello/");

这给了我:

hello/style/clients.html

但是当我这样做的时候

 String test =  "web/style/clients.html".replaceFirst("^.*?/", "${pageContext.request.contextPath}/");

给我

java.lang.IllegalArgumentException: 非法组引用

Answer 1

我的预感是它正在爆炸，因为 $ 是一个特殊字符。来自 the documentation

Note that backslashes () and dollar signs ($) in the replacement string may cause the results to be different than if it were being treated as a literal replacement string. Dollar signs may be treated as references to captured subsequences as described above, and backslashes are used to escape literal characters in the replacement string.

所以我相信你会需要类似的东西

"\\${pageContext.request.contextPath}/"