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POHow to achieve a json tree structure format
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  1. POHow to achieve a json tree structure format
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    copied!<p>My requirement to convert data from excel into tree structure. As I will be using EXTJS tree panel so i need to store java object into JSON format:</p> <pre><code>Logic ---Propositional Logic ---Predicate Logic ---Modal Logic -------Stit logic -------Doxastic logic ---Temporal logic </code></pre> <p>I read data from excel sheet and used multimap in order to associate each key with multiple values. My i/p after storing in multi map: [Logic=>Propositional logic, predicate,modal,temporal] [modal logic= stit, doxastic]</p> <p>While searching in stackoverflow forum, i found a sample code which is like this: I sent multimap in this function. I tried to use it for my objective and added gson codes in order to test.</p> <pre><code>public static Set &lt;Tree&gt; transform(Map &lt;String, List&lt;String&gt;&gt; input) { // Potential tree roots. We start with all LHS keys as potential roots, // and eliminate them when we see their keys on the RHS. Set&lt;String&gt; roots = new HashSet&lt;String&gt;(input.keySet()); // This map associates keys with the tree nodes that we create for them Map&lt;String, Tree&gt; map = new HashMap&lt;String, Tree&gt;(); Gson gs = new Gson(); String jsonString = null; for (Map.Entry&lt;String, List&lt;String&gt;&gt; entry : input.entrySet()) { String key = entry.getKey(); List&lt;String&gt; childKeys = entry.getValue(); Tree tree = map.get(key); if (tree == null) { tree = new Tree(key); map.put(key, tree); } for (String childKey : childKeys) { roots.remove(childKey); Tree child = map.get(childKey); if (child == null) { child = new Tree(childKey); map.put(childKey, child); } tree.addChild(child); jsonString =gs.toJson(tree); } System.out.println(jsonString); } Set&lt;Tree&gt; res = new HashSet&lt;Tree&gt;(roots.size()); for (String key : roots) { res.add(map.get(key)); } return res; } </code></pre> <p>I also have a Tree class :</p> <pre><code>public class Tree{ private String key; private boolean leaf; private List&lt;Tree&gt; children = new ArrayList&lt;Tree&gt;(); public Tree(String key) { this.key=key; leaf=true; } public void addChild(Tree child) { children.add(child); leaf=false; } } </code></pre> <p>The o/p i get is :</p> <pre><code>{"key":"Logic","leaf":false,"children":[{"key":"Propositional Logic","leaf":true,"children":[]},{"key":"Predicate Logic","leaf":true,"children":[]},{"key":"Modal Logic","leaf":true,"children":[]},{"key":"Temporal Logic","leaf":true,"children":[]}]} {"key":"Modal Logic","leaf":false,"children":[{"key":"STIT logic","leaf":true,"children":[]},{"key":"Doxastic Logic","leaf":true,"children":[]}]} </code></pre> <p>But i wanted the o/p to be like:</p> <pre><code>{"key":"Logic","leaf":false,"children":[{"key":"Propositional Logic","leaf":true,"children":[]},{"key":"Predicate Logic","leaf":true,"children":[]},{"key":"Modal Logic","leaf":true,"children":[{"key":"STIT logic","leaf":true,"children":[]},{"key":"Doxastic Logic","leaf":true,"children":[]},{"key":"Coalition Logic","leaf":true,"children":[]}},{"key":"Temporal Logic","leaf":true,"children":[]}]} </code></pre> <p>I am not very much familiar with Java programming so i am stuck with this. What should be added in above codes, can you please advice?</p> <p>Thanks</p>
 

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