Parse Java object to Javascript

Question

In Spring MVC and Jackson I have a really big Java object that I parse to a JSON string myBigJSONString (~1MB) and inline it into my HTML.

Then in my Javascript I do a JSON.parse(myBigJSONString) and everything works dandy.

However if I were to inline an syntactically correct Javascript object into my HTML and not a string representation thereof, my Javascript wouldn't have to read this huge string and parse it. It would already be parsed.

Question: How do I create a Javascript object from my Java object and inline it directly without going through a JSON string?

EDIT:

This is how my finished HTML looks right now:

var staticDataString = '[{\"propertyA\":\"valueA\"}, {\"propertyB\":\"valueB\"}]';
var staticData = JSON.parse(staticDataString);

This is how i want it to look

var staticData = [{propertyA:"valueA"}, {propertyB:"valueB"}];

Grim · Accepted Answer · 2015-11-16 13:33:49Z

2

In all current browsers this should work:

<script> 
  var obj =  <c:out value="${$myserlvetmapping.myjson}"></c:out>;
  alert(obj.test);
</script>

Whearat this is the Spring-Handler:

model.addAttribute("myjson","{test:2}");

Finally this would be the browsers sourcecode:

var obj =  {test:2};
alert(obj.test);

And the alert reports 2.

About the creation of the JSON i suggest to use the "adapter-pattern", this means a lot of hand-written-code.

Why do you need the hand-written-adapter? Assuming you have crosswise referenced objects in java like This:

class Man {
  Wife wife;
}
class Wife {
  Man man;
}
Man joe = new Man();
Wife ann = new Wife();
joe.wife = ann;
ann.man = joe;

Your json would be

{man:{
  name:'joe',
  wife: {
    name: 'ann',
    man: {
      name: 'joe',
      wife: {
        name: 'ann',
        man: {
          name: 'joe',
          wife: {
            .....
          }
        }
      }
    }
  }
}}

To prevent recursion you can only use the Adapter-Pattern. This would work:

public final class ManJSONAdapter {
  private final Man man;
  public ManJSONAdapter(Man man){
    this.man = man;
  }
  public String toJSON(){
    String result="{";
    if (man != null) {
      result += "name:";
      if (man.name == null){
        result += "undefined"
      } else {
        result += "'" + StringEscapeUtils.ESCAPE_ECMASCRIPT.translate(man.name) +"'";
      }
      result += ",wife:";
      if (man.wife == null) {
         result += "undefined";
      } else {
         ...
      }
    }
    result += "}";
    return result;
  }
}

edited Nov 16, 2015 at 13:33

answered Nov 16, 2015 at 11:51

Grim

2,16312 gold badges63 silver badges139 bronze badges

Sign up to request clarification or add additional context in comments.

10 Comments

Per Eriksson Over a year ago

"About the creation of the JSON" that is the point of this question.

Grim Over a year ago

Do you miss something?

Per Eriksson Over a year ago

I don't think About the creation of the JSON i suggest to use the "adapter-pattern", this means a lot of hand-written-code. is enough of an answer to the heart of the question. I don't have any circular dependencies in my object structure and it is perfectly possible for me to create a normal JSON string with all the extra " and \ included. I will try to expand my question with examples to better illustrate my point...

Grim Over a year ago

You mean you have no circular dependencies yet! What if someone add a circular dependency? A OutOfMemoryError kills your server and you will join the hall-of-fame.

Per Eriksson Over a year ago

Ok, that may be true, but don't Jackson handle such circular dependencies in its serialization from Java to JSON string?

|

Collectives™ on Stack Overflow

Parse Java object to Javascript

1 Answer 1

10 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

10 Comments

Your Answer

Sign up or log in

Post as a guest

Related