title: Java replace Japanese characters with \\p{Katakana} regular expression
body: <p>i have followed that <a href="https://stackoverflow.com/questions/10809176/regular-expressions-regex-in-japanese">link</a></p>
  
  <p>and the user "slevithan" offer using <code>\p{Katakana}</code></p>
  
  <pre><code>public static void main(String[] args) {
      String str = "マイポケット (1).csv";
      str=    str.replaceAll(  "[\\p{Katakana}]", "_");//.replaceAll("\\p{Z}", "_");
      System.out.println(str);
  }
  </code></pre>
  
  <p>but i get an error:</p>
  
  <pre><code>Exception in thread "main" java.util.regex.PatternSyntaxException: Unknown character property name {Katakana} near index 12
  [\p{Katakana}]
  </code></pre>
  
  <p>i am working with java 8 .
  what is the correct syntax for checking Japanese characters with String replaceAll ?</p>