Json Mapping Exception can not deserialize instance out of START_ARRAY token

Question

I\'m trying to parse my json request to my model. I dunno what is wrong in this code. Syntax of json looks correct and annotations on Java model also. I don\'t know why I\'m

Answer 1

You have declared parameters as a single object, but you are returning it as an array of multiple objects in your JSON document.

Your model currently defines the parameters node as a ParametersType object:

@JsonProperty( "parameters" )
@XmlElement( required = true )
protected ParametersType parameters;

This means your model object is expecting a JSON document that looks like the following:

{
    "templateId": "123",
    "parameters": {
            "parameter": [
                {
                    "key": "id",
                    "value": "1",
                    "type": "STRING_TYPE"
                },
                {
                    "key": "id2",
                    "value": "12",
                    "type": "STRING_TYPE"
                }
            ]
        },
    "documentFormat": "PDF"
}

But in your JSON document you are returning an array of ParametersType objects. So you need to change your model to be a list of ParametersType objects:

@JsonProperty( "parameters" )
@XmlElement( required = true )
protected List<ParametersType> parameters;

The fact that you are returning an array of ParametersType objects is why the parser is complaining about not being able to deserialize an object out of START_ARRAY. It was looking for a node with a single object, but found an array of objects in your JSON.

Answer 2

A couple of corrections in your pojo class ,

1)

public class ParametersType {

@JsonProperty( "parameter" )
protected List<ParameterType> parameter;

...}

Corrected POJO:

public class Parameters {

@JsonProperty( "parameter" )
protected List<Parameter> parameter;

...}

2. Also documentFormat is a string but you have declared the type as class , protected DocumentFormatType documentFormat; Should be : protected String documentFormat;