Java: Using YAML for Data Transfer
By admin on Apr 1, 2008 in Java, Programming
Previously I posted a few articles on using JSON for data transfer, in Java and .NET. Recently I have also tested YAML.
YAML stands for YAML Ain’t Markup Language. Well, sounds like GNU is not for UNIX 
. It is a human friendly data serialization standard for all programming languages.
Here I am going to show you a simple example using JYaml.
I defined my value object or data transfer object called Person, which has name, email
public class Person { private String name; private String email; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } }
To use YAML to serialize or deserialize object is very easy. JYaml supports
- Primitives and respective wrapper classes
- JavaBean compliant objects (from mappings)
- Collection (from sequences)
- List
- Set
- Map (from mappings)
- Arrays (from sequences)
- BigInteger and BigDecimal
- Date
- Custom Java Objects by implementing ObjectsWrappers yourself
To test it, see the followings
import org.ho.yaml.Yaml; import java.util.ArrayList; import java.util.List; public class YamlTest { public static void main(String[] args) { // Create a single object Person me = new Person(); me.setName("jason"); me.setEmail("[email protected]"); String yamlString = Yaml.dump(me); System.out.println(yamlString); // Create a list of objects Person another = new Person(); another.setName("alice"); another.setEmail("[email protected]"); List<Person> personList = new ArrayList<Person>(2); personList.add(me); personList.add(another); String yamlList = Yaml.dumpStream(personList.iterator()); System.out.println(yamlList); // Read a single object Person obj = (Person) Yaml.load(yamlString); System.out.println("name: " + obj.getName()); System.out.println("email: " + obj.getEmail()); System.out.println(); // Read a list of objects for (Object object : Yaml.loadStream(yamlList)) { Person p = (Person) object; System.out.println("name: " + p.getName()); System.out.println("email: " + p.getEmail()); } } }
The output
--- !Person email: [email protected] name: jason --- !Person email: [email protected] name: jason --- !Person email: [email protected] name: alice name: jason email: [email protected] name: jason email: [email protected] name: alice email: [email protected]
YAML is a good alternative for JSON. It is also used in symfony, a popular PHP framework.
