SnakeYaml error cannot create property error

I'm trying to read and write the yaml file using SnakeYaml.
here is the code :

public class SnakeYaml {
public static void main(String[] args) throws FileNotFoundException {
// TODO Auto-generated method stub
InputStream inputStream = new FileInputStream(new File("C:\\yaml\\student.yaml"));
Representer representer = new Representer();
representer.getPropertyUtils().setSkipMissingProperties(true);
Yaml yaml = new Yaml(new Constructor(Values.class),representer);
//	Map<String, Object> data = yaml.load(inputStream);
Values data = yaml.load(inputStream);
System.out.println(data);
}
}
public class Values {
private List<Image> image;
private String id;
private String name;
private String year;
private String address;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getYear() {
return year;
}
public void setYear(String year) {
this.year = year;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
private String department;
public Values()
{
}
public Values (List<Image> image, String id, String name, String year, String address, String department )
{
super ();
this.image = image;
this.id = id;
this.name = name;
this.year = year;
this.address = address;
this.department = department;
}
public List<Image> getImage() {
return image;
}
public void setImage(List<Image> image) {
this.image = image;
}
}
public class Image {
private String repository;
private String pullPolicy;
private String tag;
public Image()
{
}
public Image (String repository, String pullPolicy, String tags)
{
super();
this.repository = repository;
this.pullPolicy = pullPolicy;
this.tag = tags;
}
public String getRepository() {
return repository;
}
public void setRepository(String repository) {
this.repository = repository;
}
public String getPullPolicy() {
return pullPolicy;
}
public void setPullPolicy(String pullPolicy) {
this.pullPolicy = pullPolicy;
}
public String getTag() {
return tag;
}
public void setTag(String tag) {
this.tag = tag;
}
}

The yaml file is as below :

id: "20"
name: "Bruce"
year: "2020"
address: "Gotham City"
department: "Computer Science"
image:
repository: "test.abc.com/test"
pullPolicy: "IfNotPresent"
tag: "xyz"

getting below error

> Exception in thread "main" Cannot create property=image for
> JavaBean=oe.kubeapi.abc.Values@1372ed45 in 'reader', line
> 1, column 1:
> id: "20"
> ^ No single argument constructor found for class oe.kubeapi.abc.Image in 'reader', line 7, column 3:
> repository: "test.abc.com/test ...
> ^

not sure which property is missing . please suggest

The problem is how you structured the yaml file. The type of image attribute in class Value is a List<Image>.

public class Values {
    private List<Image> image;
    // setter & getters & constructors
}

with your yaml file like

id: "20"
name: "Bruce"
year: "2020"
address: "Gotham City"
department: "Computer Science"
image:
  repository: "test.abc.com/test"
  pullPolicy: "IfNotPresent"
  tag: "xyz"

you are saying that image property is an object with three attributes (repository, pullPolicy, tag). You could also consider it as a dictionary with three key-value pairs, but not a list.

There are different ways of doing it. All of them are documented in the spec of yaml

  [
    { repository: "test.abc.com/test1", pullPolicy: "IfNotPresent1", tag: "xyz1" },
    { repository: "test.abc.com/test2", pullPolicy: "IfNotPresent2", tag: "xyz2" }
  ]

image:
  - { repository: "test.abc.com/test1", pullPolicy: "IfNotPresent1", tag: "xyz1" }
  - { repository: "test.abc.com/test2", pullPolicy: "IfNotPresent2", tag: "xyz2" }

image:
  - repository: "test.abc.com/test1"
    pullPolicy: "IfNotPresent1"
    tag: "xyz1"
  - repository: "test.abc.com/test2"
    pullPolicy: "IfNotPresent2"
    tag: "xyz2"

if you add the following lines to your main method

Values data = yaml.load(inputStream);
data.getImage().forEach(x -> System.out.println(x.getTag()));

you will see that the attribute tag from Image class is being printed in all the cases