old_contents: var express = require('express');
  var router = express.Router();
  
  /* GET home page. */
  router.get('/testjson', function(req, res, next) {
    var data={
      "status":1,
      "msg":"ok",
      "data":{
        "name":"peter",
        "age":"17"
      }
    };
    res.json(data);
  });
  
  module.exports = router;
  
new_contents: var express = require('express');
  var router = express.Router();
  
  var data={
    "status":1,
    "msg":"ok",
    "data":{
      "name":"peter",
      "age":"17"
    }
  };
  
  /* GET home page. */
  router.get('/testjson', function(req, res, next) {
  
    var _callback = req.query.callback;
    if (_callback){
      res.type('text/javascript');
      res.send(_callback + '(' + JSON.stringify(data) + ')');
    }
    else{
      res.json(data);
    }
  });
  
  module.exports = router;
  
subject: add a test API