title: Jackson throws JsonMappingException on deserialize; demands single-String constructor?
body: <p>Another question, but it relates to this one:
  <a href="https://stackoverflow.com/questions/8367445/deserializing-json-with-jackson-why-jsonmappingexception-no-suitable-construc">Deserializing JSON with Jackson - Why JsonMappingException &quot;No suitable constructor&quot;?</a></p>
  
  <p>This time I am getting a different error, namely that the Jackson deserializer complains that I do not have a "single-String constructor/factory method" in my class ProtocolContainer.</p>
  
  <p>However, if I add a single-String constructor, like this:</p>
  
  <pre><code>public ProtocolContainer(String json) {}
  </code></pre>
  
  <p>the exception does indeed disappear, but the <code>ProtocolContainer</code> that I expected to be there is all "empty", i.e. all its properties are in their initial state, and not populated according to the JSON-string.</p>
  
  <p>Why is that?</p>
  
  <p>I'm pretty sure you shouldn't need a single-String constructor, and if you do that you should not have to populate the properties in that constructor, right?</p>
  
  <p>=)</p>