diff options
| -rw-r--r-- | poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java b/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java index 087add5cbf..483c227c23 100644 --- a/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java +++ b/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java @@ -19,6 +19,7 @@ package org.apache.poi.hwpf.converter; +import java.util.Arrays; import java.util.Locale; import org.apache.poi.util.Beta; @@ -28,8 +29,12 @@ import org.apache.poi.util.Beta; */ @Beta public final class NumberFormatter { - private static final String[] ROMAN_LETTERS = { "m", "cm", "d", "cd", "c", - "xc", "l", "xl", "x", "ix", "v", "iv", "i" }; + // use char[] instead of String to speed up StringBuilder.append(), especially in JDK 11+ + // where StringBuilder internally switched from char[] to byte[] + private static final char[][] ROMAN_LETTERS = Arrays.stream( + new String[] { "m", "cm", "d", "cd", "c", "xc", "l", "xl", "x", "ix", "v", "iv", "i" }). + map(String::toCharArray). + toArray(char[][]::new); private static final int[] ROMAN_VALUES = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 }; @@ -86,7 +91,7 @@ public final class NumberFormatter { StringBuilder result = new StringBuilder(); for ( int i = 0; i < ROMAN_LETTERS.length; i++ ) { - String letter = ROMAN_LETTERS[i]; + char[] letter = ROMAN_LETTERS[i]; int value = ROMAN_VALUES[i]; while ( number >= value ) { number -= value; |