I want to use #Function Annotation in Mule. I found only
this page about it.
but I can not get good result.
I made a new project, added a Java component, created a new class and copied this code
public class MyComponent {
public Object process(#XPath("/Envelope") Document doc
#Function("uuid") String id) {
// do stuff
}
}
but I have lot of errors. I think I must configure other things but I don't know what, nor how I can use #Function.
You need to manually declare an annotation parser in your configuration in order for annotations to be processed.
Consider this POJO:
package com.acme;
import org.mule.api.annotations.expression.XPath;
import org.mule.api.annotations.expressions.Function;
import org.w3c.dom.Document;
public class AnnotatedPojo
{
public Object process(#XPath("/Envelope") final Document doc, #Function("uuid") final String id)
{
return "Envelope text: " + doc.getDocumentElement().getTextContent() + " - ID: " + id;
}
}
You can use it with this Mule configuration:
<spring:bean class="org.mule.config.endpoint.RegistryBackedAnnotationsParserFactory" />
<flow name="testAnnotatedPojo">
<http:inbound-endpoint address="http://localhost:8080/pojo"
exchange-pattern="request-response" />
<component class="com.acme.AnnotatedPojo" />
</flow>
Example call:
$ curl -H "Content-Type: application/xml" http://localhost:8080/pojo -d'<Envelope>foo</Envelope>'
Envelope text: foo - ID: 9133fc7d-a07f-11e2-b560-4d5f883736c4
Related
I've been trying to insert a XML file into mongoDB with camel and I can't manage to make it work.
I've followed this tutorial for the first steps:
http://www.pretechsol.com/2014/09/apache-camel-mongodb-component-example.html
In my route, I convert it in JSON then use 'convertBodyTo(string.class) for mongo to recognize the file.
The code works well with regular route (sending the file to another folder for example). But when I run it for mongoDB, all I get in the console is my Process message again and again with my databased never being filled.As I don't receive any error message, I don't know how to find where the problem come from.
The mongoDB name, ip, users, password have been already checked multiple times.
I would be very grateful if someone could help me on this one. Here is the files I am using. (I will spare you the process file).
camel-context.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://camel.apache.org/schema/spring
http://camel.apache.org/schema/spring/camel-spring.xsd">
<bean id="myDb" class="com.mongodb.Mongo">
<constructor-arg index="0">
<bean class="com.mongodb.MongoURI">
<constructor-arg index="0"
value="mongodb://username:password#192.168.3.29:27017/db" />
</bean>
</constructor-arg>
</bean>
<bean id="mongodb" class="org.apache.camel.component.mongodb.MongoDbComponent"></bean>
<camelContext xmlns="http://camel.apache.org/schema/spring">
<routeBuilder ref="camelRoute" />
</camelContext>
<bean id="camelRoute" class="infotel.camel.project01.CamelRoute" />
Here is my RoutingFile:
#Component
public class CamelRoute extends SpringRouteBuilder {
final Processor myProcessor = new MyProcessor();
final Processor myProcessorMongo = new MyProcessorMongo();
final XmlJsonDataFormat xmlJsonFormat = new XmlJsonDataFormat();
#Override
public void configure() {
xmlJsonFormat.setForceTopLevelObject(true);
from("file:xml_files?noop=true").marshal(xmlJsonFormat).convertBodyTo(String.class).process(myProcessorMongo)
.to("mongodb:myDb?database=test_bignav&collection=doc&operation=insert");
}
}
And finally here is my main:
public class MyMain {
public static void main(String[] args) throws Exception {
ApplicationContext context =
new ClassPathXmlApplicationContext("META-INF/spring/camel-context.xml");
}
}
Thanks a lot.
Edit:
Here is MyProcessorMongo edited to get the error:
public class MyProcessorMongo implements Processor{
public void process(Exchange exchange) throws Exception {
System.out.println("\n file transfered to mongo: "+ exchange.getIn().getHeader("CamelFileName"));
exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class).printStackTrace();
}
}
Enable tracing with trace="true":
<camelContext trace="true" xmlns="http://camel.apache.org/schema/spring">
Dirty but quick, to get the error you can add this to you configure() method before your from :
.onException(Exception.class).handled(true).process(new Processor() {
#Override
public void process(Exchange exchange) {
exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class).printStackTrace();
}
})
The handled(true) prevents your message from being processed again and again.
thanks for your help I have been able to get the error message.
The problem actually came from mongoDB itself and not camel or code. With the change on users the connection works and I'm able to insert document inside a collection.
Remove the ".process(myProcessorMongo)" from route configuration . Input xml-> json conversion->string conversion -> Mongodb. Above route will work. And you are passing the exchange object to myProcessorMongo but Out message is null so nothing will be inserted into MongoDB . Put exchange.getOut().getBody(); in the myProcessorMongo and print it.If its coming as null u have to get the input message from exchange Obj and set it back it in to Out message property in the exchange Object.
I have heard alot of success integration story when comes to Apache Camel with Fuse. HEnce. here Im just starting to explore the Fuse IDE, with just a simple task on top of my head, i would like to achieve:
Read a fix length file
Parse the fix length file
persist it to mysql database table
I am only able to get as far as:
Read the fix length file (with Endpoint "file:src/data/Japan?noop=true")
Define a Marshal with Bindy and Define a POJO package model with #FixedLengthRecord annotation
then i am stuck... HOW TO persist the POJO into mysql database table? I can see some JDBC, IBatis and JPA end point, but how to accomplish that in Fuse IDE?
My POJO package:
package com.mbww.model;
import org.apache.camel.dataformat.bindy.annotation.DataField;
import org.apache.camel.dataformat.bindy.annotation.FixedLengthRecord;
#FixedLengthRecord(length=91)
public class Japan {
#DataField(pos=1, length=10)
private String TNR;
#DataField(pos=11, length=10)
private String ATR;
#DataField(pos=21, length=70)
private String STR;
}
Well you can use all of the following components to actually read and write from the database:
JDBC
IBATIS
MyBATIS
SPRING-JDBC
SQL
Custom Processor
I am going to show you how to use the custom processor to insert the rows into a table. The main reason for this is that you will get to work with the messages and exchange and this will give you more of a insight into Camel. All of the other components can be used by following the documentation on the camel site.
So lets review what you have. You are reading the file and converting the body to a bindy object. So for each line in your text file Camel will send a bindy object of class com.mbww.model.JAPAN to the next end point. This next end point needs to talk to the database. There is one problem I can spot immediately you are using a marshal you should be using a unmarshal.
The documentation clearly states: If you receive a message from one of the Camel Components such as File, HTTP or JMS you often want to unmarshal the payload into some bean so that you can process it using some Bean Integration or perform Predicate evaluation and so forth. To do this use the unmarshal word in the DSL in Java or the Xml Configuration.
Your bindy class looks good but it is missing getters and setters modify the class to look like this:
package com.mbww.model;
import org.apache.camel.dataformat.bindy.annotation.DataField;
import org.apache.camel.dataformat.bindy.annotation.FixedLengthRecord;
#FixedLengthRecord(length=91)
public class Japan {
#DataField(pos=1, length=10)
private String TNR;
#DataField(pos=11, length=10)
private String ATR;
#DataField(pos=21, length=70)
private String STR;
public String getTNR() {
return TNR;
}
public void setTNR(String tNR) {
TNR = tNR;
}
public String getATR() {
return ATR;
}
public void setATR(String aTR) {
ATR = aTR;
}
public String getSTR() {
return STR;
}
public void setSTR(String sTR) {
STR = sTR;
}
}
First you need to create a data source to your database in your route. First thing is to add the mysql driver jar to your maven dependencies open your pom.xml file and add the following dependency to it.
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<!-- use this version of the driver or a later version of the driver -->
<version>5.1.25</version>
</dependency>
Right now we need to declare a custom processor to use in the route that will use this driver and insert the received body into a table.
So lets create a new class in Fuse IDE called PersistToDatabase code below:
package com.mbww.JapanData;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Map;
import org.apache.camel.Body;
import org.apache.camel.Exchange;
import org.apache.camel.Handler;
import org.apache.camel.Headers;
import com.mbww.model.Japan;
import com.mysql.jdbc.Statement;
public class PersistToDatabase {
#Handler
public void PersistRecord
(
#Body Japan msgBody
, #Headers Map hdr
, Exchange exch
) throws Exception
{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your MySQL JDBC Driver?");
e.printStackTrace();
return;
}
System.out.println("MySQL JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/databasename","root", "password");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
return;
}
if (connection != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
try {
PreparedStatement stmt=connection.prepareStatement("INSERT INTO JapanDate(TNR,ATR,STR) VALUES(?,?,?)");
stmt.setString(1, msgBody.getTNR());
stmt.setString(2, msgBody.getATR());
stmt.setString(1, msgBody.getSTR());
int rows = stmt.executeUpdate();
System.out.println("Number of rows inserted: "+Integer.toString(rows));
}
catch(Exception e){
System.out.println("Error in executing sql statement: "+e.getMessage() );
throw new Exception(e.getMessage());
}
}
}
This class is a POJO nothing fancy except the #Handler annotation on the PersistRecord. This annotation tells camel that the PersistRecord method/procedure will handle the message exchange. You will also notice that the method PersistRecord has a parameter of type Japan. As mentioned earlier when you call the conversion bean in your camel route it translates each line into a Japan object and passes it along the route.
The rest of the code is just how to handle the JDBC connection and calling a insert statement.
We are almost done just one last thing to do. We need to declare this class in our camel route xml. This file will typically be called camel-route.xml or blueprint.xml depending on your arch type. Open the source tab and add the following line <bean id="JapanPersist" class="com.mbww.JapanData.PersistToDatabase"/> before the <camelContext> tag.
This declares a new spring bean called JapanPersist based on the class we just added to the camel route. You can now reference this bean inside your camel route.
Thus the final route xml file should look something like this:
<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:camel="http://camel.apache.org/schema/blueprint"
xsi:schemaLocation="
http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
http://camel.apache.org/schema/blueprint http://camel.apache.org/schema/blueprint/camel-blueprint.xsd">
<bean id="JapanPersist" class="com.mbww.JapanData.PersistToDatabase"/>
<camelContext trace="false" id="blueprintContext" xmlns="http://camel.apache.org/schema/blueprint">
<route id="JapanDataFromFileToDB">
<from uri="file:src/data/japan"/>
<unmarshal ref="Japan"/>
<bean ref="JapanPersist"/>
</route>
</camelContext>
</blueprint>
Or see screen shot below:
Once you understand this technique you can start scaling the solution by using a splitter, connection pooling and threading to do massive amount of concurrent inserts etc.
Using the technique above you learned how to inject your own beans into a camel route which give you the ability to work with the messages directly in code.
I have not tested the code so there will probably be a bug or two but the idea should be clear.
I am using #Responsebody String to send JSON.
part of my code is below.(I am sorry for open it all)
#RequestMapping(value = "/getSomeList", method = RequestMethod.GET ,
headers="Accept=application/json", produces = "text/plain;charset=UTF-8")
public #ResponseBody String getThumbList(
#RequestParam("con_id") String con_id) throws Exception{
return json;
}
And actually it sends Json. But my client requests Bson type. How can I change Json to Bson without editing global format(my json is actually just string and I heard that spring can not response bson. Is that right?).
You need to register a HttpMessageConverter that can convert to BSON.
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="MyBsonHttpMessageConverter"/>
</mvc:message-converters>
</mvc:annotation-driven>
Unfortunaly Spring has no Bson Http Message Converter, so you have to implement your own. (Or have more luck then me while google for one).
This is an old question, but it is nigh the only thing I can find on the web on this topic.
So here's how to do it. Assuming you're using Jackson as your JSON library in Spring.
Add a dependency to Michel Krämer's bson4jackson library
Create a class like so:
import com.fasterxml.jackson.databind.ObjectMapper;
import de.undercouch.bson4jackson.BsonFactory;
import de.undercouch.bson4jackson.BsonGenerator;
import org.springframework.http.MediaType;
import org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import javax.annotation.Nonnull;
public class MappingJackson2BsonHttpMessageConverter
extends AbstractJackson2HttpMessageConverter
{
public MappingJackson2BsonHttpMessageConverter(#Nonnull Jackson2ObjectMapperBuilder builder) {
super(bsonObjectMapper(builder), MediaType.parseMediaType("application/bson"));
}
#Nonnull
private static ObjectMapper bsonObjectMapper(#Nonnull Jackson2ObjectMapperBuilder om){
BsonFactory f = new BsonFactory();
f.configure(BsonGenerator.Feature.ENABLE_STREAMING, true);
return om.factory(f).build();
}
}
Add it as a #Bean to your configuration, or annotate it with #Component and make sure it's in your #ComponentScan's path.
That's it. Now, if you declare your MVC endpoint with #RequestMapping(produces = "application/bson") (in some form or another), the output will be the BSON encoding of your ResponseEntity's body.
This works with Jackson-annotated Objects which you'd normally serialize to JSON; and all the configuration you did to the Jackson ObjectMapper through Spring, modules or annotations will apply.
It also works for input as well as for output.
It also works with Feign clients.
I assume it also works with Spring's RestTemplate.
I have a test method:
#Test
public void testHello_with_muleXmlConfig() throws Exception {
MuleClient client = new MuleClient("mule-config-test.xml");
client.getMuleContext().start();
MuleMessage result = client.send("http://127.0.0.1:8080/hello", "some data", null);
assertNotNull(result);
assertNull(result.getExceptionPayload());
assertFalse(result.getPayload() instanceof NullPayload);
assertEquals("hello", result.getPayloadAsString());
}
Here (client.send("http://127.0.0.1:8080/hello", "some data", null)), I'm passing the parameter/data = 'some data'.
And I have a class:
public class HelloWorld {
public String sayHello() {
return "hello";
}
}
which is exposed as spring bean in mule-config.xml:
<spring:bean id="helloWorld" class="org.mule.application.hello.HelloWorld"/>
<flow name="HelloWorld">
<inbound-endpoint address="http://127.0.0.1:8080/hello"/>
<invoke method="sayHello" object-ref="helloWorld"/>
</flow>
What I should do to pass the parameter 'hello' into the 'sayHello()' method. If just changing it to 'sayHello(String text)' - it will not work.
You need to add this to the invoke element:
methodArguments="#[message.getPayload()]" methodArgumentTypes="java.lang.String"
Not sure about how/if invoke works: I suggest you use component instead.
If you change your method to accept a String, like for example:
public String sayHello(final String text)
{
return "hello:" + text;
}
then you also need to use an object-to-string-transformer to deserialize the inbound input stream to a String:
<flow name="HelloWorld">
<inbound-endpoint address="http://127.0.0.1:8080/hello" />
<object-to-string-transformer />
<component>
<spring-object bean="helloWorld" />
</component>
</flow>
Try This :
add this in your flow :
<invoke object-ref="helloWorld" method="sayHello" methodArguments="#[message.inboundProperties.'http.query.params'.name]" doc:name="Invoke" />
and this is the invoked method :
public String sayHello(String name) {
return String.format("Hello %s!", name);
}
While developing REST services using Spring MVC, I would like render JSON 'pretty printed' in development but normal (reduced whitespace) in production.
If you are using Spring Boot 1.2 or later the simple solution is to add
spring.jackson.serialization.INDENT_OUTPUT=true
to the application.properties file. This assumes that you are using Jackson for serialization.
If you are using an earlier version of Spring Boot then you can add
http.mappers.json-pretty-print=true
This solution still works with Spring Boot 1.2 but it is deprecated and will eventually be removed entirely. You will get a deprecation warning in the log at startup time.
(tested using spring-boot-starter-web)
I had an answer when I posted this question, but I thought I'd post it anyway in case there are better alternative solutions. Here was my experience:
First thing's first. The MappingJacksonHttpMessageConverter expects you to inject a Jackson ObjectMapper instance and perform Jackson configuration on that instance (and not through a Spring class).
I thought it would be as easy as doing this:
Create an ObjectMapperFactoryBean implementation that allows me to customize the ObjectMapper instance that can be injected into the MappingJacksonHttpMessageConverter. For example:
<bean id="jacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="objectMapper">
<bean class="com.foo.my.ObjectMapperFactoryBean">
<property name="prettyPrint" value="${json.prettyPrint}"/>
</bean>
</property>
</bean>
And then, in my ObjectMapperFactoryBean implementation, I could do this (as has been documented as a solution elsewhere on SO):
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationConfig.Feature.INDENT_OUTPUT, isPrettyPrint());
return mapper;
But it didn't work. And trying to figure out why is a nightmare. It is a major test of patience to figure Jackson out. Looking at its source code only confuses you further as it uses outdated and obtuse forms of configuration (integer bitmasks for turning on/off features? Are you kidding me?)
I essentially had to re-write Spring's MappingJacksonHttpMessageConverter from scratch, and override its writeInternal implementation to be the following:
#Override
protected void writeInternal(Object o, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException {
JsonEncoding encoding = getEncoding(outputMessage.getHeaders().getContentType());
JsonGenerator jsonGenerator =
getObjectMapper().getJsonFactory().createJsonGenerator(outputMessage.getBody(), encoding);
try {
if (this.prefixJson) {
jsonGenerator.writeRaw("{} && ");
}
if (isPrettyPrint()) {
jsonGenerator.useDefaultPrettyPrinter();
}
getObjectMapper().writeValue(jsonGenerator, o);
}
catch (JsonGenerationException ex) {
throw new HttpMessageNotWritableException("Could not write JSON: " + ex.getMessage(), ex);
}
}
The only thing I added to the existing implementation is the following block:
if (isPrettyPrint()) {
jsonGenerator.useDefaultPrettyPrinter();
}
isPrettyPrint() is just a JavaBeans compatible getter w/ matching setter that I added to my MappingJacksonHttpMessageConverter subclass.
Only after jumping through these hoops was I able to turn on or off pretty printing based on my ${json.prettyPrint} value (that is set as a property depending on how the app is deployed).
I hope this helps someone out in the future!
When you are using Jackson 2.0.0, you can do it in a way Les wanted to.
I currently use RC3 and the configuration seems to be working as expected.
ObjectMapper jacksonMapper = new ObjectMapper();
jacksonMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
translates
{"foo":"foo","bar":{"field1":"field1","field2":"field2"}}
into
{
"foo" : "foo",
"bar" : {
"field1" : "field1",
"field2" : "field2"
}
}
Might I suggest this approach, it is valid with Spring 4.0.x and possibly older versions.
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.util.List;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
#Configuration
#EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter {
#Bean
public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
mappingJackson2HttpMessageConverter.setObjectMapper(objectMapper());
return mappingJackson2HttpMessageConverter;
}
#Bean
public ObjectMapper objectMapper() {
ObjectMapper objMapper = new ObjectMapper();
objMapper.enable(SerializationFeature.INDENT_OUTPUT);
return objMapper;
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
super.configureMessageConverters(converters);
converters.add(mappingJackson2HttpMessageConverter());
}
}
Thanks to Willie Wheeler for the solution: Willie Wheeler's Spring blog
How do I make Jackson pretty-print the JSON content it generates?
Here's a simple example:
Original JSON Input:
{"one":"AAA","two":["BBB","CCC"],"three":{"four":"DDD","five":["EEE","FFF"]}}
Foo.java:
import java.io.FileReader;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ObjectWriter;
public class Foo
{
public static void main(String[] args) throws Exception
{
ObjectMapper mapper = new ObjectMapper();
MyClass myObject = mapper.readValue(new FileReader("input.json"), MyClass.class);
// this is Jackson 1.x API only:
ObjectWriter writer = mapper.defaultPrettyPrintingWriter();
// ***IMPORTANT!!!*** for Jackson 2.x use the line below instead of the one above:
// ObjectWriter writer = mapper.writer().withDefaultPrettyPrinter();
System.out.println(writer.writeValueAsString(myObject));
}
}
class MyClass
{
String one;
String[] two;
MyOtherClass three;
public String getOne() {return one;}
void setOne(String one) {this.one = one;}
public String[] getTwo() {return two;}
void setTwo(String[] two) {this.two = two;}
public MyOtherClass getThree() {return three;}
void setThree(MyOtherClass three) {this.three = three;}
}
class MyOtherClass
{
String four;
String[] five;
public String getFour() {return four;}
void setFour(String four) {this.four = four;}
public String[] getFive() {return five;}
void setFive(String[] five) {this.five = five;}
}
Output:
{
"one" : "AAA",
"two" : [ "BBB", "CCC" ],
"three" : {
"four" : "DDD",
"five" : [ "EEE", "FFF" ]
}
}
If this approach doesn't exactly fit your needs, if you search the API docs v1.8.1 for "pretty", it'll turn up the relevant components available. If you use API version 2.x then look instead at the newer API 2.1.0 docs.
Pretty print will be enable by adding and configure the MappingJackson2HttpMessageConverter converter. Disable prettyprint within production environment.
Message converter configuration
<mvc:annotation-driven>
<mvc:message-converters>
<bean id="jacksonHttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="prettyPrint" value="${json.prettyPrint}" />
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
Based on baeldung this could be a nice idea using java 8:
#Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
Optional<HttpMessageConverter<?>> converterFound;
converterFound = converters.stream().filter(c -> c instanceof AbstractJackson2HttpMessageConverter).findFirst();
if (converterFound.isPresent()) {
final AbstractJackson2HttpMessageConverter converter;
converter = (AbstractJackson2HttpMessageConverter) converterFound.get();
converter.getObjectMapper().enable(SerializationFeature.INDENT_OUTPUT);
converter.getObjectMapper().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
}
}
I had trouble getting the custom MappingJacksonHttpMessageConverter to work as suggested above but I was finally able to get it to work after struggling w/ the configuration. From the code stand point I did exactly what was mentioned above but I had to add the following configuration to my springapp-servlet.xml to get it to work.
I hope this helps others who are looking to implement the same.
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
<list>
<ref bean="jsonConverter" />
</list>
</property>
</bean>
<bean id="jsonConverter" class="com.xxx.xxx.xxx.common.PrettyPrintMappingJacksonHttpMessageConverter">
<property name="supportedMediaTypes" value="application/json" />
<property name="prettyPrint" value="true" />
</bean>
Jackson 2 has a nicer API, agreed, but it won't resolve this problem in a Spring MVC environment given Spring MVC uses ObjectMapper#writeValue(JsonGenerator, Object) to write objects out as JSON. This writeValue variant does not apply ObjectMapper serialization features such as INDENT_OUTPUT in either Jackson 1.x or 2.0.
I do think this is somewhat confusing. Since we use the ObjectMapper to construct JsonGenerators, I'd expect returned generators to be initialized based on configured ObjectMapper settings. I reported this as a issue against Jackson 2.0 here: https://github.com/FasterXML/jackson-databind/issues/12.
Les's suggestion of calling JsonGenerator#useDefaultPrettyPrinter based on the value of a prettyPrint flag is about the best we can do at the moment. I've gone ahead and created a Jackson2 HttpMessageConverter that does this based on the enabled status of the INDENT_OUTPUT SerializationFeature: https://gist.github.com/2423129.
I would make that a rendering issue, not the concern of the REST service.
Who's doing the rendering? Let that component format the JSON. Maybe it can be two URLs - one for production and another for development.