The below idea seemed to look clean, to allow the object itself to validate its values for different scenarios.

For eg:

• While creating the object, the value of Object1 and Object2 in SelfValidator object should be validated for not null.
• At one scenario like inserting the SelfValidator object to Database, validation of value1 as non-zero has to be done, which is not necessary for an Update. A new validate function: validateForInsert(), which will validate and set the error data, can be included to SelfValidator class.

But I am sure, there might be some drawbacks, design flaws, which I would like to understand and improve.

ErrorInfo.java

public class ErrorInfo {
  String errorMessage = "";

  public void setErrorMessage(String errorMessage) {
    this.errorMessage = new StringBuffer(this.errorMessage).append("\n+").append(errorMessage).toString();
  }
}

SelfValidator.java

public class SelfValidator {

  String object1;
  String object2;
  int value1;
  ErrorInfo errorInfo;

  public ErrorInfo getErrorInfo() {
    return errorInfo;
  }

  public SelfValidator(String object1, String object2, int value1) {
    super();
    this.object1 = (object1 == "")?null: object1;
    validate(this.object1, "object1");
    this.object2 = (object2 == "")?null: object2;
    validate(this.object2, "object2");
    this.value1 = value1;
  }

  private void validate(String value, String dataMember) {
    if(value == null){
        if(errorInfo == null){
            errorInfo = new ErrorInfo();
        }
        errorInfo.setErrorMessage(dataMember +" value is invalid");
    }
  }
}

Demonstrator.java

public class Demostrator {
  public static void printValidOrNot(ErrorInfo errorInfo){
    if(errorInfo == null){
        System.out.println("Object valid");
        //Proceed with manipulating the object
    }else{
        System.out.println(errorInfo.errorMessage);
        // Break and handle the error.
    }
  }
  public static void main(String[] args) {
    SelfValidator selfValidatingObject1 = new SelfValidator("Test", "Test", 1);
    printValidOrNot(selfValidatingObject1.getErrorInfo());
    
    SelfValidator selfValidatingObject2 = new SelfValidator("", "", 1);
    printValidOrNot(selfValidatingObject2.getErrorInfo());
  }
}