UnMarshalling YAML file to Java Object

This post explains unmarshalling information stored in YAML format to java object . This can be achieved with the help of YAMLMapper provided by jackson package. To explain with an example we will use the below pojo objects Employee package package2; import java.math.BigDecimal; import java.util.List; public class Employee { private String id; private String name;…… Continue reading UnMarshalling YAML file to Java Object

Marshalling Java Object to YAML format

This post explains marshalling a java object to YAML format and storing it to a file. This can be achieved with the help of YAMLMapper provided by jackson package. To explain with an example we will use the below pojo objects. Employee package package2; import java.math.BigDecimal; import java.util.List; public class Employee { private String id;…… Continue reading Marshalling Java Object to YAML format

Parsing a YAML file

In this post I will explain how to parse a YAML file using Jackson framework. We need the following jars in our classpath 1) jackson-dataformat-yaml-2.9.6.jar 2) snakeyaml-1.18.jar 3) jackson-annotations-2.9.0.jar 4) jackson-core-2.9.6.jar 5) jackson-databind-2.9.6.jar First we need to create an instance of YAMLFactory class. It is factory class used to create instance of YAMLParser (reader) and…… Continue reading Parsing a YAML file

Achieving data binding with object model

This post explains how to achieve mapping of json data represented by an object model to particular java object. Here object model is tree like data structure which reads and stores the entire json content in memory. The difference between this post and other posts in Binding section is that latter posts explains marshalling and…… Continue reading Achieving data binding with object model

Creating and Writing JSON object model to a file

This post explains how to create and save json object model to a file. In the example we build the below json object model representing person information. { “ssn” : “111111111”, “name” : { “firstName” : “Ronald”, “lastName” : “Childs” }, “phoneNumbers” : [ “1112223333”, “4445556666” ] } The main code is as shown below…… Continue reading Creating and Writing JSON object model to a file

Reading json data in non-streaming way (object model)

We can read a json file and create an object model of it, using the ObjectMapper’s readTree api. ObjectMapper class is responsible for parsing the json file and create appropriate java objects. It uses Jackson’s parsing feature internally for reading the json file. They are many overloaded method of readTree available in ObjectMapper. In this…… Continue reading Reading json data in non-streaming way (object model)

Printing json data in a formatted way

This post explains how to print json data in a properly formatted way, whether the destination is console, file etc. For example when the below code prints the json data to a file, the output will be as shown below Initial Code package package11; import java.io.File; import java.io.FileWriter; import java.io.IOException; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; public…… Continue reading Printing json data in a formatted way

Handling json deserialization error

This post explains how to handle errors generated while deserializing the json file. This can be achieved by implementing an interface “DeserializationProblemHandler” provided by jackson framework as shown below UnMarshallingErrorHandler package package1; import java.io.IOException; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; import com.fasterxml.jackson.databind.deser.DeserializationProblemHandler; public class UnMarshallingErrorHandler extends DeserializationProblemHandler { @Override public boolean handleUnknownProperty(DeserializationContext ctxt,…… Continue reading Handling json deserialization error

Getting JsonGenerator settings

This post explains how to get JsonGenerator settings. JsonGenerator class obtained from JsonFactory is responsible for writing json data as a stream instead of constructing an entire object model in memory and then writing to destination. The list of settings that can be turned on or off are present in an enumeration JsonGenerator.Feature. The below…… Continue reading Getting JsonGenerator settings