Ну синтаксисом он от джавы слабо отличается. Более гибкий разве что.

function toFlatJSON(root) {
var dict = [];
var result = { "root": root, "dict": dict };
var label = {};
function flatten(obj) {
var n = 0;
function moveIfNotFlat(key) {
if ((typeof obj[key] === 'object' && obj[key].label != label) || obj[key.constructor === Array]) {
for(var i in dict)
if(dict == obj[key]){
obj[key] = { i: i, label: label };
return;
}
var i = dict.push(obj[key]) - 1;
obj[key] = { i: i, label: label };
n++;
}
};
if (typeof obj === 'object') {
//object
Object.keys(obj).forEach(function (key) {
moveIfNotFlat(key);
});
} else {
//array
for (var key = 0; key < obj.length; key++)
moveIfNotFlat(key);
}
return n;
}
flatten(root);
do {
n = 0;
for (var i in dict)
n += flatten(dict);
} while (n > 0);
Object.keys(root).forEach(function (key) {
if (typeof root[key] === 'object')
delete root[key].label;
});
for (var i in dict)
if (typeof dict === 'object')
Object.keys(dict).forEach(function (key) {
if (typeof dict[key] === 'object')
delete dict[key].label;
});
else if(dict.constructor === Array){
for (var key = 0; key < dict.length; key++)
delete dict[key].label;
}
return JSON.stringify(result);
}

function fromFlatJSON(s){
var obj = JSON.parse(s);
var dict = obj.dict;
function restore(obj){
function replaceIfLink(key){
if(typeof obj[key] === 'object')
obj[key] = dict[obj[key].i];
}
if (typeof obj === 'object') {
//object
Object.keys(obj).forEach(function (key) {
replaceIfLink(key);
});
} else {
//array
for (var key = 0; key < obj.length; key++)
replaceIfLink(key);
}
}
restore(obj.root);
for(var key in dict)
restore(dict[key]);
return obj.root;
}

var a = {};
var b = [a,1,"j"];
a.b = b;
console.log(a.b[0].b);
var obj = { a: a, b: { c: 2, d: { e: 4, f: a } } };
console.log(obj);
//console.log(JSON.stringify(obj));
var fj = toFlatJSON(obj);
console.log(fj);
//console.log("fj = " + fj);
//console.log(JSON.parse(fj));
//console.log(fromFlatJSON(fj));
console.log(fromFlatJSON(fj));
console.log(fromFlatJSON(fj).b.d.f.b[0]);