title: Flushing a Hashmap of custom Objects in JSON Format
body: <p>I have a this map: </p>
  
  <pre><code>HashMap&lt;LatLng,ArrayList&lt;String&gt;&gt; dictionary = new  HashMap&lt;LatLng,ArrayList&lt;String&gt;&gt;() ;
  </code></pre>
  
  <p>and I'm trying to flush it to disk in JSON format using jackson like this:</p>
  
  <pre><code>ObjectMapper mapper = new ObjectMapper();
  mapper.writeValue(new File(MyApplication.getOfflineData()+"/Dictionary.json"), dictionary);
  </code></pre>
  
  <p>this is how is written the json file:</p>
  
  <pre><code>"lat/lng: (39.151783,20.97455)": [
  "/mnt/sdcard/Android/data/example.perifereia_hpeirou/files/lala/photos/pic1.nomedia",
  "/mnt/sdcard/Android/data/example.perifereia_hpeirou/files/lala/photos/pic2.nomedia",
  "/mnt/sdcard/Android/data/example.perifereia_hpeirou/files/lala/photos/pic3.nomedia",
  "/mnt/sdcard/Android/data/example.perifereia_hpeirou/files/lala/photos/pic4.nomedia"
  ]
  </code></pre>
  
  <p>I think this is not correct. I think the "lat/lng": shouldn't exist, how can I correct this?
  Thank you for your time.</p>