[feat] Use append method from JsonKeyValuePair

Author: ANeumann82

src/main/java/net/sf/jsqlparser/expression/JsonFunction.java

@@ -184,20 +184,7 @@ public StringBuilder appendObject(StringBuilder builder) {
             if (i > 0) {
                 builder.append(", ");
             }
-            if (keyValuePair.isUsingKeyKeyword()
-                    && keyValuePair.getSeparator() == JsonKeyValuePairSeparator.VALUE) {
-                builder.append("KEY ");
-            }
-            builder.append(keyValuePair.getKey());
-
-            if (keyValuePair.getValue() != null) {
-                builder.append(keyValuePair.getSeparator().getSeparatorString());
-                builder.append(keyValuePair.getValue());
-            }
-
-            if (keyValuePair.isUsingFormatJson()) {
-                builder.append(" FORMAT JSON");
-            }
+            keyValuePair.append(builder);
             i++;
         }
 

src/main/java/net/sf/jsqlparser/expression/JsonKeyValuePair.java

@@ -39,7 +39,8 @@ public JsonKeyValuePair(Object key, Object value, boolean usingKeyKeyword,
         this.key = Objects.requireNonNull(key, "The KEY of the Pair must not be null");
         this.value = value;
         this.usingKeyKeyword = usingKeyKeyword;
-        this.separator = separator;
+        this.separator =
+                Objects.requireNonNull(separator, "The KeyValuePairSeparator must not be NULL");
     }
 
     public boolean isUsingKeyKeyword() {
@@ -138,13 +139,14 @@ public Object getValue() {
     }
 
     public StringBuilder append(StringBuilder builder) {
-        if (isUsingValueKeyword()) {
-            if (isUsingKeyKeyword()) {
-                builder.append("KEY ");
-            }
-            builder.append(getKey()).append(" VALUE ").append(getValue());
-        } else {
-            builder.append(getKey()).append(":").append(getValue());
+        if (isUsingKeyKeyword() && getSeparator() == JsonKeyValuePairSeparator.VALUE) {
+            builder.append("KEY ");
+        }
+        builder.append(getKey());
+
+        if (getValue() != null) {
+            builder.append(getSeparator().getSeparatorString());
+            builder.append(getValue());
         }
 
         if (isUsingFormatJson()) {