Fix parsing of String value in json

Closes gh-11992

Author: snicoll

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@
  *
  * @author Dave Syer
  * @author Jean de Klerk
+ * @author Stephane Nicoll
  * @since 1.2.0
  * @see JsonParserFactory
  */
@@ -112,12 +113,7 @@ private Map<String, Object> parseMapInternal(String json) {
 		for (String pair : tokenize(json)) {
 			String[] values = StringUtils.trimArrayElements(StringUtils.split(pair, ":"));
 			String key = trimLeadingCharacter(trimTrailingCharacter(values[0], '"'), '"');
-			Object value = null;
-			if (values.length > 0) {
-				String string = trimLeadingCharacter(
-						trimTrailingCharacter(values[1], '"'), '"');
-				value = parseInternal(string);
-			}
+			Object value = parseInternal(values[1]);
 			map.put(key, value);
 		}
 		return map;

spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,6 +56,13 @@ public void doubleValue() {
 		assertThat(map.get("spam")).isEqualTo(1.23d);
 	}
 
+	@Test
+	public void stringContainingNumber() {
+		Map<String, Object> map = this.parser.parseMap("{\"foo\":\"123\"}");
+		assertThat(map).hasSize(1);
+		assertThat(map.get("foo")).isEqualTo("123");
+	}
+
 	@Test
 	public void emptyMap() {
 		Map<String, Object> map = this.parser.parseMap("{}");