Merge pull request #41876 from hyunmin0317

* pr/41876:
  Polish "Refactor BasicJsonParser to simplify JSON parsing logic"
  Refactor BasicJsonParser to simplify JSON parsing logic

Closes gh-41876

Author: mhalbritter

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java

@@ -52,7 +52,7 @@ public List<Object> parseList(String json) {
 
 	private List<Object> parseListInternal(int nesting, String json) {
 		List<Object> list = new ArrayList<>();
-		json = trimLeadingCharacter(trimTrailingCharacter(json, ']'), '[').trim();
+		json = trimEdges(json, '[', ']').trim();
 		for (String value : tokenize(json)) {
 			list.add(parseInternal(nesting + 1, value));
 		}
@@ -70,37 +70,39 @@ private Object parseInternal(int nesting, String json) {
 			return parseMapInternal(nesting + 1, json);
 		}
 		if (json.startsWith("\"")) {
-			return trimTrailingCharacter(trimLeadingCharacter(json, '"'), '"');
+			return trimEdges(json, '"', '"');
 		}
-		try {
-			return Long.valueOf(json);
-		}
-		catch (NumberFormatException ex) {
-			// ignore
-		}
-		try {
-			return Double.valueOf(json);
-		}
-		catch (NumberFormatException ex) {
-			// ignore
-		}
-		return json;
+		return parseNumber(json);
 	}
 
 	private Map<String, Object> parseMapInternal(int nesting, String json) {
 		Map<String, Object> map = new LinkedHashMap<>();
-		json = trimLeadingCharacter(trimTrailingCharacter(json, '}'), '{').trim();
+		json = trimEdges(json, '{', '}').trim();
 		for (String pair : tokenize(json)) {
 			String[] values = StringUtils.trimArrayElements(StringUtils.split(pair, ":"));
 			Assert.state(values[0].startsWith("\"") && values[0].endsWith("\""),
 					"Expecting double-quotes around field names");
-			String key = trimLeadingCharacter(trimTrailingCharacter(values[0], '"'), '"');
+			String key = trimEdges(values[0], '"', '"');
 			Object value = parseInternal(nesting, values[1]);
 			map.put(key, value);
 		}
 		return map;
 	}
 
+	private Object parseNumber(String json) {
+		try {
+			return Long.valueOf(json);
+		}
+		catch (NumberFormatException ex) {
+			try {
+				return Double.valueOf(json);
+			}
+			catch (NumberFormatException ex2) {
+				return json;
+			}
+		}
+	}
+
 	private static String trimTrailingCharacter(String string, char c) {
 		if (!string.isEmpty() && string.charAt(string.length() - 1) == c) {
 			return string.substring(0, string.length() - 1);
@@ -115,6 +117,10 @@ private static String trimLeadingCharacter(String string, char c) {
 		return string;
 	}
 
+	private static String trimEdges(String string, char leadingChar, char trailingChar) {
+		return trimTrailingCharacter(trimLeadingCharacter(string, leadingChar), trailingChar);
+	}
+
 	private List<String> tokenize(String json) {
 		List<String> list = new ArrayList<>();
 		int index = 0;