[bug-66532] more performant way to iterate over codepoints. Thanks to Matthias Raschhofer

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1908458 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 33 insertions, 2 deletions

diff --git a/poi/src/main/java/org/apache/poi/util/CodepointsUtil.java b/poi/src/main/java/org/apache/poi/util/CodepointsUtil.java
index 9f2d01780c..71fcdbe85e 100644
--- a/poi/src/main/java/org/apache/poi/util/CodepointsUtil.java
+++ b/poi/src/main/java/org/apache/poi/util/CodepointsUtil.java
@@ -18,12 +18,28 @@
 package org.apache.poi.util;
 
 import java.util.Iterator;
+import java.util.PrimitiveIterator;
 
 @Internal
 public class CodepointsUtil {
+
+    /**
+     * @param text to iterate over
+     * @return iterator with Strings representing the codepoints
+     * @see #primitiveIterator(String) a more performnt iterator
+     */
     public static Iterator<String> iteratorFor(String text) {
         return text.codePoints()
                 .mapToObj(codePoint -> new String(Character.toChars(codePoint)))
                 .iterator();
     }
+
+    /**
+     * @param text to iterate over
+     * @return iterator with ints representing the codepoints
+     * @since POI 5.2.4
+     */
+    public static PrimitiveIterator.OfInt primitiveIterator(String text) {
+        return text.codePoints().iterator();
+    }
 }
\ No newline at end of file
diff --git a/poi/src/test/java/org/apache/poi/util/TestCodepointsUtil.java b/poi/src/test/java/org/apache/poi/util/TestCodepointsUtil.java
index 3610535c95..f6d31ef5d4 100644
--- a/poi/src/test/java/org/apache/poi/util/TestCodepointsUtil.java
+++ b/poi/src/test/java/org/apache/poi/util/TestCodepointsUtil.java
@@ -23,6 +23,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.function.IntConsumer;
 
 import org.junit.jupiter.api.Test;
 
@@ -38,8 +39,22 @@ class TestCodepointsUtil {
         List<String> codePoints = new ArrayList<>();
         CodepointsUtil.iteratorFor(unicodeSurrogates).forEachRemaining(codePoints::add);
         assertEquals(17, codePoints.size());
-        for(String point : codePoints){
-            assertTrue(point.length() >=1 && point.length() <= 2, "codepoint " + point + "is wrong size");
+        for (String point : codePoints) {
+            assertTrue(point.length() >= 1 && point.length() <= 2, "codepoint " + point + "is wrong size");
+        }
+    }
+
+    @Test
+    void testPrimitiveIterator() {
+        final String unicodeSurrogates = "\uD835\uDF4A\uD835\uDF4B\uD835\uDF4C\uD835\uDF4D\uD835\uDF4E"
+                + "abcdef123456";
+        List<String> codePoints = new ArrayList<>();
+        CodepointsUtil.primitiveIterator(unicodeSurrogates).forEachRemaining((IntConsumer) (i) -> {
+                    codePoints.add(new String(Character.toChars(i)));
+                });
+        assertEquals(17, codePoints.size());
+        for (String point : codePoints) {
+            assertTrue(point.length() >= 1 && point.length() <= 2, "codepoint " + point + "is wrong size");
         }
     }