How to load YAML data in SnakeYAML?

In this tutorial, we will learn how to load YAML data in SnakeYAML.

Loading a YAML formatted String

public class LoadingString {

    public static void main(String[] args) {
        Yaml yaml = new Yaml();
        Object obj = yaml.load(getStringYmlData());
        System.out.println("Loaded object type: " + obj.getClass());
        System.out.println(obj);
    }

    public static String getStringYmlData() {
        return "name: Joe\n"
                + "phone: 111-111-1111\n"
                + "address: Park Dr, Charlie Hill";
    }
}

Output

Loaded object type: class java.util.LinkedHashMap
{name=Joe, phone=111-111-1111, address=Park Dr, Charlie Hill}

Loading from a file

src/main/resources/person.yml

name: Joe
phone: 111-111-11111
address: Park Dr, Charlie Hill

public class LoadFile {
    public static void main(String[] args) throws IOException {
        Yaml yaml = new Yaml();
        try (InputStream in = LoadFile.class.getResourceAsStream("/person.yml")) {
            Object obj = yaml.load(in);
            System.out.println("Loaded object type:" + obj.getClass());
            System.out.println(obj);
        }
    }
}

Output

Loaded object type:class java.util.LinkedHashMap
{name=Joe, phone=111-111-11111, address=Park Dr, Charlie Hill}

Loading multiple YAML documents from a file

Per YAML specification, multiple YAML documents can be added in a single file separated by '---'.

src/main/resources/persons.yml

name: Joe
phone: 111-111-1111
address: Park Dr, Charlie Hill
---
name: Trish
phone: 111-111-11111
address: Small Vine, River Town

public class LoadAll {
    public static void main(String[] args) throws IOException {
       loadFromFile("/person.yml");
        loadFromFile("/persons.yml");
    }

    private static void loadFromFile(String path) throws IOException {
        System.out.printf("-- loading from %s --%n", path);
        Yaml yaml = new Yaml();
        try (InputStream in = LoadAll.class.getResourceAsStream(path)) {
            Iterable<Object> itr = yaml.loadAll(in);
            System.out.println("-- iterating loaded Iterable --");
            for (Object o : itr) {
                System.out.println("element type: " + o.getClass());
                System.out.println(o);
            }
        }
    }
}

Output

-- loading from /person.yml --
-- iterating loaded Iterable --
element type: class java.util.LinkedHashMap
{name=Joe, phone=111-111-11111, address=Park Dr, Charlie Hill}
-- loading from /persons.yml --
-- iterating loaded Iterable --
element type: class java.util.LinkedHashMap
{name=Joe, phone=111-111-1111, address=Park Dr, Charlie Hill}
element type: class java.util.LinkedHashMap
{name=Trish, phone=111-111-11111, address=Small Vine, River Town}

Example Project

Dependencies and Technologies Used:

• snakeyaml 1.18: YAML 1.1 parser and emitter for Java.
• JDK 1.8
• Maven 3.3.9