From 2e74251d1b0d5db01201f2cd04047b1dbde094ea Mon Sep 17 00:00:00 2001
From: Piotr Maj <pm@jcake.com>
Date: Fri, 14 Mar 2014 21:36:49 -0700
Subject: [PATCH] Add support for sorting json keys

Add `jsonSortKeys` property to HttpMapperProperties.

Fixes gh-498
---
 .../autoconfigure/web/HttpMapperProperties.java   | 15 ++++++++++++++-
 .../HttpMessageConvertersAutoConfiguration.java   |  9 ++++++++-
 .../asciidoc/appendix-application-properties.adoc |  1 +
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMapperProperties.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMapperProperties.java
index 3c1750f2109..168b93978a5 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMapperProperties.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMapperProperties.java
@@ -21,11 +21,16 @@ import org.springframework.http.converter.HttpMessageConverter;
 
 /**
  * Configuration properties to configure {@link HttpMessageConverter}s.
+ * 
+ * @author Dave Syer
+ * @author Piotr Maj
  */
 @ConfigurationProperties(name = "http.mappers", ignoreUnknownFields = false)
 public class HttpMapperProperties {
 
-	private boolean jsonPrettyPrint = false;
+	private boolean jsonPrettyPrint;
+
+	private boolean jsonSortKeys;
 
 	public void setJsonPrettyPrint(boolean jsonPrettyPrint) {
 		this.jsonPrettyPrint = jsonPrettyPrint;
@@ -35,4 +40,12 @@ public class HttpMapperProperties {
 		return this.jsonPrettyPrint;
 	}
 
+	public void setJsonSortKeys(boolean jsonSortKeys) {
+		this.jsonSortKeys = jsonSortKeys;
+	}
+
+	public boolean isJsonSortKeys() {
+		return this.jsonSortKeys;
+	}
+
 }
diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMessageConvertersAutoConfiguration.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMessageConvertersAutoConfiguration.java
index 4340e225f12..d6b56f4860d 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMessageConvertersAutoConfiguration.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/HttpMessageConvertersAutoConfiguration.java
@@ -38,12 +38,14 @@ import org.springframework.http.converter.json.MappingJackson2HttpMessageConvert
 
 import com.fasterxml.jackson.databind.Module;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for {@link HttpMessageConverter}s.
  * 
  * @author Dave Syer
  * @author Christian Dupuis
+ * @author Piotr Maj
  */
 @Configuration
 @ConditionalOnClass(HttpMessageConverter.class)
@@ -87,7 +89,12 @@ public class HttpMessageConvertersAutoConfiguration {
 		@ConditionalOnMissingBean
 		@Primary
 		public ObjectMapper jacksonObjectMapper() {
-			return new ObjectMapper();
+			ObjectMapper objectMapper = new ObjectMapper();
+			if (this.properties.isJsonSortKeys()) {
+				objectMapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS,
+						true);
+			}
+			return objectMapper;
 		}
 
 		@Bean
diff --git a/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc b/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
index 82098d8adf5..c169c3190aa 100644
--- a/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
+++ b/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
@@ -64,6 +64,7 @@ server.tomcat.max-threads = 0 # number of threads in protocol handler
 
 # SPRING MVC (HttpMapperProperties)
 http.mappers.json-pretty-print=false # pretty print JSON
+http.mappers.json-sort-keys=falose # sort keys
 spring.view.prefix= # MVC view prefix
 spring.view.suffix= # ... and suffix
 spring.resources.cache-period= # cache timeouts in headers sent to browser