JavaBean Validation - Constraint Annotations Examples

import javax.validation.Valid;
import javax.validation.constraints.NotNull;

public interface Employee {

    String getName();

    @Valid
    @NotNull
    PhoneNumber getPhoneNumber();

    @NotNull
    String getDept();
}

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

public class Person {
    @NotNull
    @Size(min = 1, max = 300)
    private String name;

    public Person(String name) {
        this.name = name;
    }
    .............
}

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Pattern;

public class PhoneNumber {
    @NotNull
    private String type;
    @Pattern(regexp = "\\d{3}-\\d{3}-\\d{4}")
    private String number;

    public PhoneNumber(String type, String number) {
        this.type = type;
        this.number = number;
    }
    .............
}