From bf6735ce4bf833170d19d91922d9b4d17aa4aefc Mon Sep 17 00:00:00 2001
From: Michal Kordas <kordas.michal@gmail.com>
Date: Fri, 7 Aug 2015 23:44:25 +0200
Subject: [PATCH] Use StringBuilder to concatenate strings. #1555

Fixes `StringReplaceableByStringBuffer` inspection violations.

Description:
Reports any variables declared as java.lang.String which are repeatedly appended to. Such variables may be more efficiently declared as java.lang.StringBuffer or java.lang.StringBuilder.
---
 .../tools/checkstyle/checks/imports/ImportOrderCheck.java    | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheck.java
index 93481b800..acd0823e9 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheck.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/imports/ImportOrderCheck.java
@@ -233,6 +233,7 @@ public class ImportOrderCheck
 
         for (int i = 0; i < packageGroups.length; i++) {
             String pkg = packageGroups[i];
+            final StringBuilder pkgBuilder = new StringBuilder(pkg);
             Pattern grp;
 
             // if the pkg name is the wildcard, make it match zero chars
@@ -249,9 +250,9 @@ public class ImportOrderCheck
             }
             else {
                 if (!Utils.endsWithChar(pkg, '.')) {
-                    pkg += ".";
+                    pkgBuilder.append('.');
                 }
-                grp = Pattern.compile("^" + Pattern.quote(pkg));
+                grp = Pattern.compile("^" + Pattern.quote(pkgBuilder.toString()));
             }
 
             groups[i] = grp;