I would like to serialize a given hashmap into json and deserialize it back to the original map. Here I would like to make this generic so that it behaves seamlessly regardless of the type of the value. I am using the following code snippet for constructing the map and then serailizing it as json: This is wor…
Tag: jackson
Why is Jackson using the wrong element name when serializing?
I have a Object that I would like Jackson to serialize like this… To try this I create the following class… But when I serialize I get… As you can see the problem here is the child tags should be account but in fact are accounts. I tried hacking around with the localname but can’t find…
Serializing JSON with class metadata
I’ve used both Gson and Jackson and both of them offer a way to deal with polymorphism. For example, with Jackson you need to declare the class with a @JsonSubTypes and add each and every @JsonSubTypes.Type you have. Similar thing happens with Gson. My question is if there is an option to make it work l…
JSON parse error: Cannot deserialize instance of ArrayList
I’m trying to send a JSON to a POST bodyRequest service to use this information as a Java ArrayList or something like that. When I try to do it, I receive a deserialize error This is my JSON: {information: [ {fields: “Periods Offered”, tables: “Courses”, columns: “Academic …
How to Parse Json containing Array of Arrays Java
I have a Json which contains array of Arrays, now I need to parse that Json and count the elements, and after reaching certain limit I need to put it into result Json. I was able to parse till one level and count the elements. How can I parse multiple levels and get the object in same format: here is
Deserializing JSON in Java using Jackson
I have the following sample fragment of JSON I am trying to deserialize. { “total”: 2236, “issues”: [{ “id”: “10142”, “key”: &…
Jackson JsonRootName doesn’t add any root value
I am serialising an object, which I’d like to put a root value for. This is my class. This is how I am serialising it: But the serialised value is: While I was hopping to have a root json value as fed in the class definition. Could you help with that please? Answer Output: You need to enable WRAP_ROOT_V…
Java multi-schema generator using annotations
I have a series of inter-related Java classes which form a super-set of possible schema. I’m looking for some way to annotate/tag individual fields such that I can create separate JSON schema for each ‘namespace’. A simple example: Output would have separate Alice and Bob schema, where Alice…
Why Jackson ObjectMapper give me this error converting JSON field into a Date object? Can not deserialize value of type java.util.Date from String
I have this JSON object: that have to be mappend on this DTO class: To do this mapping I am using Jackson ObjectMapper, in this way: When I try to map the JSON dateTime field with the Date dateTime in my DTO class I am obtaining the following exception message: As you can see the value of the dateTime field
Bulk upload CSV file into Elasticsearch using JavaAPI
I want to bulk upload the csv file into Elasticsearch using JAVA API (without using logstash). Elasticsearch version – 6.6 I have tried the below program using Jackson format to get source Map for IndexRequest. Because I can’t predefined the POJO variables. So I used dynamic Map from CSV file I go…