Multiple code improvements fix 1: squid:S1199, squid:S1066, squid:S1854, squid:S1165

Author: George Kankava

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

@@ -419,10 +419,8 @@ public void visit(PivotXml pivot) {
         for (Column col : pivot.getForColumns()) {
             col.accept(this);
         }
-        if (pivot.getInSelect() != null) {
-            if (selectVisitor != null) {
-                pivot.getInSelect().accept(selectVisitor);
-            }
+        if (pivot.getInSelect() != null && selectVisitor != null) {
+            pivot.getInSelect().accept(selectVisitor);
         }
     }
 

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

@@ -43,20 +43,16 @@ public static boolean isHintMatch(String comment) {
 
     public final void setComment(String comment) {
         Matcher m;
-        {
-            m = SINGLE_LINE.matcher(comment);
-            if (m.find()) {
-                this.value = m.group(1);
-                this.singleLine = true;
-                return;
-            }
+        m = SINGLE_LINE.matcher(comment);
+        if (m.find()) {
+            this.value = m.group(1);
+            this.singleLine = true;
+            return;
         }
-        {
-            m = MULTI_LINE.matcher(comment);
-            if (m.find()) {
-                this.value = m.group(1);
-                this.singleLine = false;
-            }
+        m = MULTI_LINE.matcher(comment);
+        if (m.find()) {
+            this.value = m.group(1);
+            this.singleLine = false;
         }
     }
 

src/main/java/net/sf/jsqlparser/expression/operators/relational/RegExpMatchOperator.java

@@ -55,6 +55,8 @@ public String getStringExpression() {
 				return "!~";
 			case NOT_MATCH_CASEINSENSITIVE:
 				return "!~*";
+			default:
+				break;
 		}
 		return null;
 	}

src/main/java/net/sf/jsqlparser/statement/create/table/CreateTable.java

@@ -132,7 +132,7 @@ public void setIfNotExists(boolean ifNotExists) {
 
     @Override
     public String toString() {
-        String sql = "";
+        String sql;
         String createOps = PlainSelect.getStringList(createOptionsStrings, false, false);
 
         sql = "CREATE " + (unlogged ? "UNLOGGED " : "") +