X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Futil%2FStringUtils.java;fp=src%2Fjalview%2Futil%2FStringUtils.java;h=f0bc177a7c5d4c46ef628c0cbcbe8a0612214a79;hb=586ade46bdcd05ff028a1cff82c3c527326d28ec;hp=1f33522c7ce5c8324d94bd0e1a1e1b222871be46;hpb=adcef27f5747b4e70e89a56c3735bc3afb8ce9bf;p=jalview.git

diff --git a/src/jalview/util/StringUtils.java b/src/jalview/util/StringUtils.java
index 1f33522..f0bc177 100644
--- a/src/jalview/util/StringUtils.java
+++ b/src/jalview/util/StringUtils.java
@@ -545,4 +545,29 @@ public class StringUtils
     }
     return enc;
   }
+
+  /**
+   * Answers true if the string is not empty and consists only of digits, or
+   * characters 'a'-'f' or 'A'-'F', else false
+   * 
+   * @param s
+   * @return
+   */
+  public static boolean isHexString(String s)
+  {
+    int j = s.length();
+    if (j == 0)
+    {
+      return false;
+    }
+    for (int i = 0; i < j; i++)
+    {
+      int c = s.charAt(i);
+      if (!(c >= '0' && c <= '9' || c >= 'a' && c <= 'f' || c >= 'A' && c <= 'F'))
+      {
+        return false;
+      }
+    }
+    return true;
+  }
 }