From 1f18181ef5a2a897dc543340a15b380dfd4cf49d Mon Sep 17 00:00:00 2001
From: Karl-Philipp Richter <krichter722@aol.de>
Date: Mon, 21 May 2018 06:10:07 +0200
Subject: [PATCH] Improve implementation hint in InefficientEmptyStringCheck

The alternative implementation mentions iterating over the string and
checking for whitespace which is pretty clear, however, showing the
implementation doesn't hurt, nor does the hint for Apache
commons-lang's StringUtils.isBlank which does exactly that.

The if statement in the demonstration of inefficient code can lead to
confusion because users _might_ think that the check is only
inefficient inside an if statement although it's clear from the
description that it's not.
---
 .../performance/InefficientEmptyStringCheckRule.java | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/performance/InefficientEmptyStringCheckRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/performance/InefficientEmptyStringCheckRule.java
index f6c1023425..4f84d1f058 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/performance/InefficientEmptyStringCheckRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/performance/InefficientEmptyStringCheckRule.java
@@ -13,7 +13,7 @@ import net.sourceforge.pmd.lang.java.symboltable.JavaNameOccurrence;
  * This rule finds code which inefficiently determines empty strings. This code
  *
  * <pre>
- *         if(str.trim().length()==0){....
+ * str.trim().length()==0
  * </pre>
  *
  * <p>
@@ -22,8 +22,16 @@ import net.sourceforge.pmd.lang.java.symboltable.JavaNameOccurrence;
  * </p>
  *
  * <pre>
- * Character.isWhitespace(str.charAt(i));
+ * private boolean checkTrimEmpty(String str) {
+ *     for(int i=0; i<str.length(); i++) {
+ *         if(!Character.isWhitespace(str.charAt(i))) {
+ *             return false;
+ *         }
+ *     }
+ *     return true;
+ * }
  * </pre>
+ * or Apache commons-lang's <code>StringUtils.isBlank</code>.
  *
  * @author acaplan
  */