Add Strings.substring() that handles short strings.

drewr · Jan 9, 2014 · 9caf302 · 9caf302
1 parent 01b18ad
commit 9caf302
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/src/main/java/org/elasticsearch/common/Strings.java b/src/main/java/org/elasticsearch/common/Strings.java
@@ -1548,4 +1548,21 @@ public static String randomBase64UUID(Random random) {
             throw new ElasticsearchIllegalStateException("should not be thrown");
         }
     }
+
+    /**
+     * Return substring(beginIndex, endIndex) that is impervious to string length.
+     */
+    public static String substring(String s, int beginIndex, int endIndex) {
+        if (s == null) {
+            return s;
+        }
+
+        int realEndIndex = s.length() > 0 ? s.length() - 1 : 0;
+
+        if (endIndex > realEndIndex) {
+            return s.substring(beginIndex);
+        } else {
+            return s.substring(beginIndex, endIndex);
+        }
+    }
 }