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Jackson Exceptions – Problems and Solutions

1. Introduction In this example, we shall go through the most common Jackson API exceptions encountered while working for serialization and deserialization. We will see what caused the exception to be thrown and how to fix it. Let’s dive deep. Table Of Contents 1. Introduction 2. InvalidDefinitionException: No Creators, like default constructor, exist 3. MismatchedInputException: Out of START_ARRAY token 4. ...

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Jackson Annotation Examples

This example is a deep dive into Jackson Annotations. It covers almost all the annotations with code examples. We will learn how to use the existing annotations, create our custom annotations and finally how to completely disable Jackson annotations. If you are new to the Jackson API for JSON serialization and deserialization, check out this article on Introduction to Jackson ...

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Introduction to Jackson ObjectMapper

In this example, we will learn about the ObjectMapper class from Jackson and its capabilities to serialize POJOs(Plain Old Java Objects) into JSON strings and deserialize JSON strings back into Java objects, with some examples. 1. Where To Start? The first step to getting our hands dirty with ObjectMapper and Jackson data binding is to get the libraries and add ...

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Read JSON From a URL Example Using Data Pipeline

I have a problem. I want to read JSON from a URL. Naturally, like anybody else, I googled for some solutions. There were a lot of solutions shared in Stack Overflow and other sites. I tried some of them but I’d like to share the one where I used the Data Pipeline Java library. 1. Tools and Prerequisites Data Pipeline ...

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Java JSON parser Example

In this post, we feature a comprehensive Java JSON parser Example. JSON is simply a text format that facilitates reading and writing. It is a widely used data-interchange language because its parsing and its generation is easy for machines. In Java language there are many ways for JSON processing. 1. JSON Parsers In this section we will see four different ...

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JSON.Simple Example to read and write JSON in Java

In this example we are going to see a very nice JSON framwork, JSON.simple. In this tutorial we are going to see how to read and write JSON to file using this framework, and you will notice yourself how simple :) it really is. 1. JSON.simple library and dependencies If your are using Maven to build your project, you just ...

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Enable Pretty Print JSON Output using Jackson example

As you might have noticed in the previous JSON tutorials, the output of the programs is not properly aligned, which makes it hard to read. For this demonstration we are going to use the Student class from this example.             Student.java: package com.javacodegeeks.java.core; public class Student { private int id; private String firstName; private String ...

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Jackson Streaming API to read and write JSON example

Jackson project has implemented a very useful Streaming API which is also called incremental mode. This is the most efficient way to process JSON content. It has the lowest memory and processing overhead, and can often match performance of many binary data formats available on Java platform. It’s a bit tricky to use though because you have to handle JSON ...

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Jackson Tree Model example

In this example we are going to see how to use Jackson Tree Model. This model is very similar in many ways with the DOM representation. We are going to see how to create the tree model and update the JSON object with new values.                   Here is the file we are ...

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Convert Java Map To / From JSON using Jackson example

With this example we are going to see how to convert a java.util.Map Object to /from JSON representation using the Jackson parser. Converting Map to / from JSON comes naturally because they have a pretty similar representation and usage. Take a look at the precious Jackson tutorial where we showed how to convert a user defined Java Object to / ...

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