Favourite tutorials for developers
This article shows how to return a JSON response in the Jersey application, using Jackson 2.x. Tested with: Jersey 3.0.2, Grizzly 3 HTTP Server, Jackson 2.12.2 , Java 11, Maven, JUnit 5 and JSONassert 1.5 (Unit Test)
Using Jackson as JSON provider in RESTEasy. With RESTEasy auto scanning enabled. When starting up, it hits following errors and failed to start up any of the RESTEasy services: Illegal to inject a message body into a singleton into public org.codehaus.jackson.jaxrs.JacksonJsonProvider
Many like Jackson JSON processor, and it supported in RESTEasy. In this tutorial, we show you how to convert an object to JSON format and return it back to the client. To integrate Jackson with RESTEasy, you just need to include “resteasy-jackson-provider.jar“. When RESTEasy returned a json output, it will use Jackson provider to convert it automatically. You do not need to code a single line to integrate both.
In Jackson, we can use writerWithDefaultPrettyPrinter() to pretty print the JSON output. Tested with Jackson 2.9.8 1. Pretty Print JSON 1.1 By default, Jackson print in compact …
This Jackson tutorial show you how to use JsonGenerator to write JSON string and JSON array into a file, furthermore, read it with JsonParser. Jackson Streaming APIs: JsonGenerator – Write JSON, JsonParser – Parse JSON
In Jackson, we can use Tree Model to represent the JSON structure, and perform the CRUD operations via JsonNode, similar to the XML DOM tree. This Jackson Tree Model is useful, especially in cases where a JSON structure does not map nicely to Java classes.
In Jackson, we can use mapper.readValue(json, Map.class) to convert a JSON string to a Map
Few Jackson examples to convert a JSON array string to a List.
In Jackson, we can use @JsonView to limit or control fields display for different users. Puts @JsonView on field level to limit fields display for different views. Below example, show you how to enable the JsonView with mapper.writerWithView()
In Jackson, we can use @JsonInclude(JsonInclude.Include.NON_NULL) to ignore the null fields. To ignore the null fields, put @JsonInclude on class level or field level. Alternatively, we also can configure to ignore null fields globally with ObjectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL)
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