From a11661d284f7951659fcd1370831eddca06a7dac Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <awilkinson@pivotal.io>
Date: Thu, 7 Nov 2019 09:52:08 +0000
Subject: [PATCH] Trim whitespace in BasicJsonParser

Previously, whitespace in between the keys and values in the JSON was
not trimmed correctly in BasicJsonParser which lead to it incorrectly
parsing JSON with whitespace between the opening of a list ([) and the
opening of a map ({).

This commit updates the parser to trim unwanted whitespace and adds a
test to AbstractJsonParserTests to verify the whitespace handling
behaviour across all JsonParser implementations.

Closes gh-18911
---
 .../springframework/boot/json/BasicJsonParser.java    |  6 +++---
 .../boot/json/AbstractJsonParserTests.java            | 11 +++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java
index 7bfaf0997f3..b24f98e36a0 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java
@@ -49,7 +49,7 @@ public class BasicJsonParser extends AbstractJsonParser {
 
 	private List<Object> parseListInternal(String json) {
 		List<Object> list = new ArrayList<>();
-		json = trimLeadingCharacter(trimTrailingCharacter(json, ']'), '[');
+		json = trimLeadingCharacter(trimTrailingCharacter(json, ']'), '[').trim();
 		for (String value : tokenize(json)) {
 			list.add(parseInternal(value));
 		}
@@ -97,7 +97,7 @@ public class BasicJsonParser extends AbstractJsonParser {
 
 	private Map<String, Object> parseMapInternal(String json) {
 		Map<String, Object> map = new LinkedHashMap<>();
-		json = trimLeadingCharacter(trimTrailingCharacter(json, '}'), '{');
+		json = trimLeadingCharacter(trimTrailingCharacter(json, '}'), '{').trim();
 		for (String pair : tokenize(json)) {
 			String[] values = StringUtils.trimArrayElements(StringUtils.split(pair, ":"));
 			String key = trimLeadingCharacter(trimTrailingCharacter(values[0], '"'), '"');
@@ -151,7 +151,7 @@ public class BasicJsonParser extends AbstractJsonParser {
 			index++;
 		}
 		if (build.length() > 0) {
-			list.add(build.toString());
+			list.add(build.toString().trim());
 		}
 		return list;
 	}
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java
index fa6d9d0d47d..43cecfe5517 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java
@@ -101,6 +101,17 @@ public abstract class AbstractJsonParserTests {
 				.parseMap("{\"foo\":[{\"foo\":\"bar\",\"spam\":1},{\"foo\":\"baz\",\"spam\":2}]}");
 		assertThat(map).hasSize(1);
 		assertThat(((List<Object>) map.get("foo"))).hasSize(2);
+		assertThat(map.get("foo")).asList().allMatch(Map.class::isInstance);
+	}
+
+	@SuppressWarnings("unchecked")
+	@Test
+	public void nestedLeadingAndTrailingWhitespace() {
+		Map<String, Object> map = this.parser.parseMap(
+				" {\"foo\": [ { \"foo\" : \"bar\" , \"spam\" : 1 } , { \"foo\" : \"baz\" , \"spam\" : 2 } ] } ");
+		assertThat(map).hasSize(1);
+		assertThat(((List<Object>) map.get("foo"))).hasSize(2);
+		assertThat(map.get("foo")).asList().allMatch(Map.class::isInstance);
 	}
 
 	@Test