How can I inject a map into an object using only Core Java?

I have a map with 4 key-value(String, Object) pairs and a class with 3 fields, I want to invoke the setter method based on the key name and set them.

```
{
 "variableA": "A",
 "variableB": true,
 "variableC": 1,
 "variableD": "DONT USE"
}

public Class Example {
  public void setVaraibleA(String variableA);
  public void setVaraibleB(Boolean variableB);
  public void setVaraibleC(Integer variableC);
}

Example example = new Example();
// Do something to map it
assert(example.getVariableA.equals("A"));
assert(example.getVariableB.equals(true));
assert(example.getVariableC.equals(1));

```