title: spring jackson Map Deserialization
body: <p>I'm passing via a Spring controller a json object that looks like this:</p>
  
  <pre><code>{
    "dataset":"myDataset",
    "typeProperties":[
      "myProperty"
    ],
    "stopWords":{
      "de":[ "daß","allem","dem"],
      "fr":["salut"]
    }
  }
  </code></pre>
  
  <p>The corresponding java object is:</p>
  
  <pre><code>public class DatasetConfigRequest {
      String dataset = "";
      List&lt;String&gt; typeProperties;
      HashMap&lt;String,ArrayList&lt;String&gt;&gt; stopWords = new HashMap&lt;String,ArrayList&lt;String&gt;&gt;();
  
  //getter and setters
  </code></pre>
  
  <p>But when  I pass it I get the following error:</p>
  
  <pre><code>JSON parse error: Cannot deserialize instance of `java.util.HashMap&lt;java.lang.Object,java.lang.Object&gt;` out of START_ARRAY token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `java.util.HashMap&lt;java.lang.Object,java.lang.Object&gt;` out of START_ARRAY token
   at [Source: (PushbackInputStream); line: 1, column: 104] (through reference chain: eu.qanswer.core2.server.controller.payload.dataset.DatasetConfigRequest["stopWords"])]
  </code></pre>
  
  <p>I understand that the problem is the HashMap with values a ArrayList. But how to solve this?</p>
  
  <p>Thank you
  D063520</p>