Java正则表达式在字符串中某个单词前后获得2个字符串

例如，我有以下文本和电子邮件：

String text ="For move information please contact us: [email protected], ask Peter to help."
String email="[email protected]";

因此，我想得到两个10个字符大小的字符串，一个来自电子邮件的左侧，另一个来自右侧。结果我想看：左-联系我们：右：，问皮特

现在，while循环中的matcher.find（）返回false。结果，leftContext和rightContext均为null。

这是我的代码：

String email = "[email protected]";
int nLeft = 5;
int nRight = 5;
String leftContext;
String rightContext;

String wordDelRegEx = "[^а-яА-Яa-zA-Z0-9.-]+?";
        String leftRegEx = "(\\w{" + nLeft + "})";
        String rightRegEx = "(\\w{" + nRight + "})";

        //matches something like: aaaaaaa [email protected] bbbbbbbbbb
        String contextRe = leftRegEx + wordDelRegEx +email + wordDelRegEx + rightRegEx;

        String h ="For move information please contact us: [email protected], ask Peter to help."
        Pattern pattern = Pattern.compile(contextRe);
        Matcher matcher = pattern.matcher(h);

        while (matcher.find()) {
            leftContext = matcher.group(1);
            rightContext = matcher.group(2);
        }

        System.out.println("Left: " + leftContext);
        System.out.println("Right: " + rightContext);