ICU-23124 Fix exception type in BreakIterator for OOB index values
diff --git a/icu4j/main/core/src/main/java/com/ibm/icu/text/RuleBasedBreakIterator.java b/icu4j/main/core/src/main/java/com/ibm/icu/text/RuleBasedBreakIterator.java
index f5f43bb..e8ed116 100644
--- a/icu4j/main/core/src/main/java/com/ibm/icu/text/RuleBasedBreakIterator.java
+++ b/icu4j/main/core/src/main/java/com/ibm/icu/text/RuleBasedBreakIterator.java
@@ -524,12 +524,12 @@ public int preceding(int offset) {
 
 
     /**
-     * Throw IllegalArgumentException unless begin <= offset < end.
+     * Throw IndexOutOfBoundsException unless begin <= offset < end.
      * @stable ICU 2.0
      */
     protected static final void checkOffset(int offset, CharacterIterator text) {
         if (offset < text.getBeginIndex() || offset > text.getEndIndex()) {
-            throw new IllegalArgumentException("offset out of bounds");
+            throw new IndexOutOfBoundsException("offset out of bounds");
         }
     }
 
diff --git a/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/BreakIteratorTest.java b/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/BreakIteratorTest.java
index f246ab4..e014e1e 100644
--- a/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/BreakIteratorTest.java
+++ b/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/BreakIteratorTest.java
@@ -158,7 +158,7 @@ public void TestBug4153072() {
                     errln("Didn't get exception with offset = " + index +
                                     " and begin index = " + begin);
             }
-            catch (IllegalArgumentException e) {
+            catch (IndexOutOfBoundsException e) {
                 if (index >= begin)
                     errln("Got exception with offset = " + index +
                                     " and begin index = " + begin);