remove unused StringUtils#diff()

Author: amarkevich

core/src/main/java/org/apache/cxf/common/util/StringUtils.java

@@ -60,14 +60,6 @@ public static boolean isEmpty(List<String> list) {
         return list.size() == 1 && isEmpty(list.get(0));
     }
 
-    public static String diff(String str1, String str2) {
-        int index = str1.lastIndexOf(str2);
-        if (index > -1) {
-            return str1.substring(str2.length());
-        }
-        return str1;
-    }
-
     public static String getFirstFound(String contents, String regex) {
         if (isEmpty(regex) || isEmpty(contents)) {
             return null;

core/src/test/java/org/apache/cxf/common/util/StringUtilsTest.java

@@ -27,16 +27,6 @@
 
 public class StringUtilsTest {
 
-    @Test
-    public void testDiff() throws Exception {
-        String str1 = "http://local/SoapContext/SoapPort/greetMe/me/CXF";
-        String str2 = "http://local/SoapContext/SoapPort";
-        String str3 = "http://local/SoapContext/SoapPort/";
-        assertEquals("/greetMe/me/CXF", StringUtils.diff(str1, str2));
-        assertEquals("greetMe/me/CXF", StringUtils.diff(str1, str3));
-        assertEquals("http://local/SoapContext/SoapPort/", StringUtils.diff(str3, str1));
-    }
-
     @Test
     public void testGetFirstFound() throws Exception {
         String regex = "velocity-\\d+\\.\\d+\\.jar";