Java Springboot consume rest api map to a model

how to consume restful webservice in java spring boot
how to call third party api in spring boot
spring boot rest api example
spring resttemplate dependency
spring boot restful web services json example
resttemplate configuration in spring boot
hello world rest api spring boot
calling a rest service from inside another rest service

I'm trying to map the response of an API to my object:

class Person {
  private Long id;
  private String firstname;
  private String lastname;

  public Person(Long id, String firstname, String lastname)
...

and my api call looks like:

RestTemplate restTemplate = new RestTemplate();
Person person = restTemplate.getForObject("http://xxx/getPerson", Person.class);

Which returns a json that looks like:

{
 "id": 1,
 "firstname": "first",
 "lastname": "last"
}

Unfortunately I'm getting the following error:

Type definition error: [simple type, class xxx.Person]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `xxx.Person` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator)\n at [Source: (PushbackInputStream); line: 4, column: 5]

Any idea why? I have a constructor in my class so I'm not too sure why this is throwing an error. Thanks!


As the exception clearly points out:

(no Creators, like default construct, exist)

You have no default constructor for your class Person.

Any idea why?

Because you explicitly defined a constructor and just due to this behavior, the default constructor will not be generated automatically.

So you should deal with it, and there are two things you need to care about:

  1. providing a default constructor either you defining it explicitly or using an lombok annotation @NoArgsConstructor;
  2. another headsup might be properties mismatching issue, if the json doesn't have all the properties your class defines, you should also ignore them explicitly by @JsonIgnoreProperties(ignoreUnknown = true) to the class or add @JsonIgnore for the extra fields separately.

Tutorial, So building on top of HTTP, REST APIs provide the means to build flexible APIs Our example models a simple payroll service that manages the employees of a company. Despite being small, this Java class contains much: I am getting frustrated by the number of people calling any HTTP-based interface a REST API. Java Springboot consume rest api map to a model [duplicate] Posted by: admin October 24, 2018 Leave a comment. Questions: Tags: api, java, rest, spring


You need to create a default Constructor first. Also, you can use @JsonIgnoreProperties(ignoreUnknown = true) annotation to ignore any other attributes than those defined in the model.

Take a look at this example - https://spring.io/guides/gs/consuming-rest/

Getting Started, It also shows values of com.example and consuming-rest as the Group and RELEASE' id 'java' } group = 'com.example' version = '0.0.1-SNAPSHOT' With project setup complete, you can create a simple application that consumes a RESTful service. This uses the same annotations but maps onto other data fields. A more useful way to consume a REST web service is programmatically. To help you with that task, Spring provides a convenient template class called RestTemplate. RestTemplate makes interacting with most RESTful services a one-line incantation. And it can even bind that data to custom domain types. First, you need to create a domain class to


There is no Default Constructor in your Person class, you can create it manually or you can use lombok @NoargConstructor on top of class to create it

Since you declared argument constructor it's your responsibility to create no arg constructor

Consuming REST API's with Spring, Spring boot became quite popular as a framework for microservices. In this tutorial I will show you how to produce and consume REST API's with Spring boot​. I mapped it to TaskDTO[] and used Java 8 streams to collect it as a list. itself and map it to MessageDTO , then we add the message to the model  In the last tutorial we created a small REST API. So now that the “producing REST API” step is completed, it’s time to start consuming it in another Spring boot project. Last time we’ve already set up a module for this project, called spring-boot-rest-client. Creating a REST client


REST Client with Java, Spring Boot and Object Mapping, REST Client that uses Object Mapping to load a POJO from a RestTemplate request.Duration: 11:08 Posted: Nov 29, 2017 Check the pom.xml, SpringBoot would have already added parent <artifactId>spring-boot-starter-parent</artifactId> and <artifactId>spring-boot-starter-web</artifactId> which we selected while creating the Maven project. These dependencies are enough to consume REST API using RestTemplate. Step 2: Create a resource representation class.


Javarevisited: How to Consume JSON from RESTful Web Service , If want to learn more about Spring Boot and REST APIs, I also suggest you Here is our complete Java program to consume a RESTful Web All you need to tell is the name of the class you want to map the incoming JSON response. to indicate that any properties not bound in any of model classes like  Sometimes you want to connect to a REST API from a Java application. There are several approaches to it, from parsing raw JSON content to model the classes in Java with all possible details. In this post, I describe how to solve this in a practical manner, especially the fact of not having the JSON schema for the data that you’re retrieving


Spring RestTemplate - Spring REST Client Example, After learning to build Spring REST API for XML representation and JSON representation, let's build Spring REST client to consume APIs which we have written  In this Spring Boot RestTemplate POST request test example, we will create a POST API and then test it by sending request body along with request headers using postForEntity () method. Make sure to have spring-boot-starter-test dependency in the project to enable loading of spring text context, bean initialization and dependency management.