Fix bug that ignored custom json prefix

Issue: SPR-10817

spring-web/src/main/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.java

@@ -21,14 +21,6 @@ import java.lang.reflect.Type;
 import java.nio.charset.Charset;
 import java.util.List;
 
-import com.fasterxml.jackson.core.JsonEncoding;
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
-import com.fasterxml.jackson.databind.JavaType;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.MediaType;
@@ -38,6 +30,14 @@ import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
 import org.springframework.util.Assert;
 
+import com.fasterxml.jackson.core.JsonEncoding;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
 /**
  * Implementation of {@link org.springframework.http.converter.HttpMessageConverter HttpMessageConverter}
  * that can read and write JSON using <a href="http://jackson.codehaus.org/">Jackson 2's</a> {@link ObjectMapper}.
@@ -199,7 +199,7 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 
 		try {
 			if (this.jsonPrefix != null) {
-				jsonGenerator.writeRaw("{} && ");
+				jsonGenerator.writeRaw(this.jsonPrefix);
 			}
 			this.objectMapper.writeValue(jsonGenerator, object);
 		}

spring-web/src/main/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverter.java

@@ -28,7 +28,6 @@ import org.codehaus.jackson.map.ObjectMapper;
 import org.codehaus.jackson.map.SerializationConfig;
 import org.codehaus.jackson.map.type.TypeFactory;
 import org.codehaus.jackson.type.JavaType;
-
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.MediaType;
@@ -196,7 +195,7 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 
 		try {
 			if (this.jsonPrefix != null) {
-				jsonGenerator.writeRaw("{} && ");
+				jsonGenerator.writeRaw(this.jsonPrefix);
 			}
 			this.objectMapper.writeValue(jsonGenerator, object);
 		}

spring-web/src/test/java/org/springframework/http/converter/json/AbstractMappingJacksonHttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -16,10 +16,6 @@
 
 package org.springframework.http.converter.json;
 
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
@@ -35,6 +31,8 @@ import org.springframework.http.MockHttpOutputMessage;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 
+import static org.junit.Assert.*;
+
 /**
  * Base class for Jackson and Jackson 2 converter tests.
  *

spring-web/src/test/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -22,16 +22,17 @@ import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
 
-import com.fasterxml.jackson.databind.JavaType;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import static org.junit.Assert.*;
 import org.junit.Test;
-
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.MediaType;
 import org.springframework.http.MockHttpInputMessage;
 import org.springframework.http.MockHttpOutputMessage;
 
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import static org.junit.Assert.*;
+
 /**
  * Jackson 2.x converter tests.
  *
@@ -112,6 +113,24 @@ public class MappingJackson2HttpMessageConverterTests extends AbstractMappingJac
 		assertEquals("{" + NEWLINE_SYSTEM_PROPERTY + "  \"name\" : \"Jason\"" + NEWLINE_SYSTEM_PROPERTY + "}", result);
 	}
 
+	@Test
+	public void prefixJson() throws Exception {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		getConverter().setPrefixJson(true);
+		getConverter().writeInternal("foo", outputMessage);
+
+		assertEquals("{} && \"foo\"", outputMessage.getBodyAsString(Charset.forName("UTF-8")));
+	}
+
+	@Test
+	public void prefixJsonCustom() throws Exception {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		getConverter().setJsonPrefix(")]}',");
+		getConverter().writeInternal("foo", outputMessage);
+
+		assertEquals(")]}',\"foo\"", outputMessage.getBodyAsString(Charset.forName("UTF-8")));
+	}
+
 
 	public static class PrettyPrintBean {
 

spring-web/src/test/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverterTests.java

@@ -24,14 +24,14 @@ import java.util.List;
 
 import org.codehaus.jackson.map.type.TypeFactory;
 import org.codehaus.jackson.type.JavaType;
-import static org.junit.Assert.*;
 import org.junit.Test;
-
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.MediaType;
 import org.springframework.http.MockHttpInputMessage;
 import org.springframework.http.MockHttpOutputMessage;
 
+import static org.junit.Assert.*;
+
 /**
  * Jackson 1.x converter tests.
  *
@@ -109,6 +109,24 @@ public class MappingJacksonHttpMessageConverterTests extends AbstractMappingJack
 		assertEquals("{" + NEWLINE_SYSTEM_PROPERTY + "  \"name\" : \"Jason\"" + NEWLINE_SYSTEM_PROPERTY + "}", result);
 	}
 
+	@Test
+	public void prefixJson() throws Exception {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		getConverter().setPrefixJson(true);
+		getConverter().writeInternal("foo", outputMessage);
+
+		assertEquals("{} && \"foo\"", outputMessage.getBodyAsString(Charset.forName("UTF-8")));
+	}
+
+	@Test
+	public void prefixJsonCustom() throws Exception {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		getConverter().setJsonPrefix(")]}',");
+		getConverter().writeInternal("foo", outputMessage);
+
+		assertEquals(")]}',\"foo\"", outputMessage.getBodyAsString(Charset.forName("UTF-8")));
+	}
+
 
 	public static class PrettyPrintBean {