Add check to handle edge cases

sianghwee · sianghwee · commit df1f5df900d8 · 2022-01-22T04:52:23.000+08:00
diff --git a/src/main/java/utils/StringUtil.java b/src/main/java/utils/StringUtil.java
@@ -54,6 +54,8 @@ public static String reduceWhitespace(String s) {
     }
 
     public static String join(Collection<String> strings, CharSequence delimiter) {
+        if (strings == null)
+            return null;
         StringJoiner sj = new StringJoiner(delimiter);
         for (String s: strings) {
             sj.add(s);

Original file line number	Diff line number	Diff line change
`@@ -54,6 +54,8 @@ public static String reduceWhitespace(String s) {`
`54`	`54`	`}`
`55`	`55`
`56`	`56`	`public static String join(Collection<String> strings, CharSequence delimiter) {`
	`57`	`+ if (strings == null)`
	`58`	`+ return null;`
`57`	`59`	`StringJoiner sj = new StringJoiner(delimiter);`
`58`	`60`	`for (String s: strings) {`
`59`	`61`	`sj.add(s);`