HSSFWorkbook.getSheet(): Return first found sheet

We do not need to loop over all sheets always but should
be able to return the first found sheet.

This may change semantics for cases where there are
multiple sheets where name only differs in case, but
the JavaDoc did not state which one will be returned.

All three implementations (HSSF, XSSF, SXSSF)
now behave the same way.

Closes #653

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1918982 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 13 insertions, 6 deletions

diff --git a/poi-ooxml/src/main/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java b/poi-ooxml/src/main/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java
index da64a880f2..401529839b 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java
@@ -808,6 +808,9 @@ public class SXSSFWorkbook implements Workbook {
     /**
      * Get sheet with the given name
      *
+     * If there are multiple matches, the first sheet from the list
+     * of sheets is returned.
+     *
      * @param name of the sheet
      * @return Sheet with the name provided or <code>null</code> if it does not exist
      */
diff --git a/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java b/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
index 7c03b27fa4..3703f0dd4b 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
@@ -1208,6 +1208,9 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Date1904Su
     /**
      * Get sheet with the given name (case insensitive match)
      *
+     * If there are multiple matches, the first sheet from the list
+     * of sheets is returned.
+     *
      * @param name of the sheet
      * @return XSSFSheet with the name provided or {@code null} if it does not exist
      */
diff --git a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
index 336fc2bc3e..9442589189 100644
--- a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
+++ b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
@@ -1055,24 +1055,25 @@ public final class HSSFWorkbook extends POIDocument implements Workbook {
     }
 
     /**
-     * Get sheet with the given name (case insensitive match)
+     * Get sheet with the given name (case insensitive match).
+     *
+     * If there are multiple matches, the first sheet from the list
+     * of sheets is returned.
      *
      * @param name of the sheet
      * @return HSSFSheet with the name provided or {@code null} if it does not exist
      */
-
     @Override
     public HSSFSheet getSheet(String name) {
-        HSSFSheet retval = null;
-
         for (int k = 0; k < _sheets.size(); k++) {
             String sheetname = workbook.getSheetName(k);
 
             if (sheetname.equalsIgnoreCase(name)) {
-                retval = _sheets.get(k);
+                return _sheets.get(k);
             }
         }
-        return retval;
+
+        return null;
     }
 
     /**