Java server returns JSON map items in the wrong order

This is a old bug I have forgotten to register.
lib/js/test uses a Java server to run its unit tests, and by doing so I could see that there is a small problem on the Java JSON map decoder.

The unit test "testMap" should echo a map<int,int> back to the client without changing it, but it's messing up with the items order, e.g.

{7=77, 8=88, 9=99}

returns

{8=88, 9=99, 7=77}

To run the server:
thrift-trunk/lib/java$ ant compile-test
thrift-trunk/lib/js/test$ ant testserver
and go to http://localhost:8088/test/test.html

Java test server console output:
[java] Incoming content: [1,"testMap",1,0,{"1":{"map":["i32","i32",3,

{"7":77,"8":88,"9":99}

]}}]
[java] testMap(8=88, 9=99, 7=77)
[java] Outgoing content: [1,"testMap",2,0,{"0":{"map":["i32","i32",3,

{"8":88,"9":99,"7":77}

]}}]

It's minor but it would be nice if any Java developer could have a look on it.
Thanks a lot.

ps.: the same works with a cpp server