Custom HttpMessageConverter with @ResponseBody to do Json things

I don't like Jackson.

I want to use ajax but with Google Gson.

So I'm trying to figure out how to implement my own HttpMessageConverter to use it with @ResponseBody annotation. Can someone take a time to show me the way I should go? What configurations should I turn on? Also I'm wondering if I can do this and still use <mvc:annotation-driven />?

Thanks in advance.

I've already asked it in Spring Community Foruns about 3 days ago with no answer so I'm asking here to see if I get a better chance. Spring Community Forums link to my question

I've also made an exhaustive search on the web and found something interesting on this subject but it seems they're thinking to put it in Spring 3.1 and I'm still using spring 3.0.5: Jira's Spring Improvement ask

Well... now I'm trying to debug Spring code to find out myself how to do this, but I'm having some problems like I've said here: Spring Framework Build Error

If there is another way to do this and I'm missing it, please let me know.

Edit Report

Well... it was so hard to find the answer and I had to follow so many clues to incomplete information that I think it will be good to post the complete answer here. So it will be easier for the next one searching for this.

First I had to implement the custom HttpMessageConverter:


package net.iogui.web.spring.converter;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.nio.charset.Charset;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;

import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;

public class GsonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {

    private Gson gson = new Gson();

    public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

    public GsonHttpMessageConverter(){
        super(new MediaType("application", "json", DEFAULT_CHARSET));
    }

    @Override
    protected Object readInternal(Class<? extends Object> clazz,
                                  HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {

        try{
            return gson.fromJson(convertStreamToString(inputMessage.getBody()), clazz);
        }catch(JsonSyntaxException e){
            throw new HttpMessageNotReadableException("Could not read JSON: " + e.getMessage(), e);
        }

    }

    @Override
    protected boolean supports(Class<?> clazz) {
        return true;
    }

    @Override
    protected void writeInternal(Object t, 
                                 HttpO


                        
                        
                            answered 2011-02-24T02:10:33.747

Custom HttpMessageConverter with @ResponseBody to do Json things

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