Json字符串解析为具有多个对象的Java对象

{
    \"entry\": \"132456\",
    \"product\": 
    {
        \"item\": \"123456\",
        \"prompts\": 
        [
            {
                \"promptId\": \"1\",
                \"promptNumber\": \"109\",
                \"promptType\": 4,
                \"promptTypeDesc\": \"desc1\",
                \"validations\":
                [
                    {
                        \"minLen\": 10,
                        \"maxLen\": 10,
                        \"required\": true 
                    } 
                ] 
            } 
        ] 
    }
}

import java.util.List;

public class Info {

    private String entry;
    private Product product;

    public class Product {

        private String item;
        private List<Prompt> prompts;

        public class Prompt {

            private String promptId;
            private String promptNumber;
            private int promptType;
            private String promptTypeDes;
            private List<Validation> validations;

            public class Validation {

                private int maxLen;
                private int minLen;
                private boolean required;
            }
        }
    }
}

public static void main(String args[]){

    String input = \"{\"
            + \"\\\"entry\\\": \\\"132456\\\",\"
            + \"\\\"product\\\": {\\\"item\\\": \\\"123456\\\",\"
            + \"\\\"prompts\\\":[{\\\"promptId\\\": \\\"1\\\",\"
            + \"\\\"promptNumber\\\": \\\"109\\\",\"
            + \"\\\"promptType\\\": 4,\"
            + \"\\\"promptTypeDesc\\\": \\\"desc1\\\",\"
            + \"\\\"validations\\\":[{\\\"minLen\\\": 10,\"
            + \"\\\"maxLen\\\": 10\"
            + \",\\\"required\\\": true}]}]}}\";

    Gson gson = new GsonBuilder().setPrettyPrinting().create();
    Info item = gson.fromJson(input, Info.class);

    String jsonOutput = gson.toJson(item);
    System.out.println(jsonOutput);
}

run:
{
  \"entry\": \"132456\",
  \"product\": {
    \"item\": \"123456\",
    \"prompts\": [
      {
        \"promptId\": \"1\",
        \"promptNumber\": \"109\",
        \"promptType\": 4,
        \"validations\": [
          {
            \"maxLen\": 10,
            \"minLen\": 10,
            \"required\": true
          }
        ]
      }
    ]
  }
}
BUILD SUCCESSFUL (total time: 0 seconds)