a generic builder

Builder.java

import java.lang.reflect.Field;

/**
 * Utility method for quickly building mock models
 */
public class Builder {
    public static <T> T build(Class<T> clazz, Object... keyValues) {
        try {
            return build(clazz, clazz.newInstance(), keyValues);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    public static <T> T build(Class<T> clazz, T instance, Object[] keyValues) {
        String key = null;
        for (Object keyValue : keyValues) {
            if(key==null) {
                key = (String) keyValue;
            } else {
                Field declaredField;
                try {
                    declaredField = clazz.getDeclaredField(key);
                } catch (NoSuchFieldException e) {
                    throw new RuntimeException(e);
                }
                declaredField.setAccessible(true);
                try {
                    declaredField.set(instance, keyValue);
                } catch (IllegalAccessException e) {
                    throw new RuntimeException(e);
                }
                key = null;
            }
        }
        return instance;
    }
}

BuilderTest.java

import org.testng.Assert;
import org.testng.annotations.Test;

import static com.papajohns.test.mock.Builder.build;

public class BuilderTest {
    @Test
    public void testBuilder() {
        Person person = build(Person.class);
        Assert.assertNull(person.getName());

        person = build(Person.class, "id",1001,
                "name", build(Name.class, "firstName", "Darren", "lastName","Day")
               ,"address",build(Address.class,"street","106 Birch Street","city","Tricity","state","Euphoria")
               ,"birthDate","March 1, 1900");

        Assert.assertEquals(person.getId(),1001);
        Assert.assertEquals(person.getName().getFirstName(),"Darren");
        Assert.assertEquals(person.getBirthDate(),"March 1, 1900");
        Assert.assertEquals(person.getAddress().getState(),"Euphoria");
    }

    public static class Name {
        private String firstName;
        private String lastName;

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }

        public String getLastName() {
            return lastName;
        }

        public void setLastName(String lastName) {
            this.lastName = lastName;
        }
    }

    public static class Address {
        private String street;
        private String city;
        private String state;

        public String getStreet() {
            return street;
        }

        public void setStreet(String street) {
            this.street = street;
        }

        public String getCity() {
            return city;
        }

        public void setCity(String city) {
            this.city = city;
        }

        public String getState() {
            return state;
        }

        public void setState(String state) {
            this.state = state;
        }
    }

    public static class Person {
        private int id;
        private Name name;
        private Address address;
        private String birthDate;

        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public Name getName() {
            return name;
        }

        public void setName(Name name) {
            this.name = name;
        }

        public Address getAddress() {
            return address;
        }

        public void setAddress(Address address) {
            this.address = address;
        }

        public String getBirthDate() {
            return birthDate;
        }

        public void setBirthDate(String birthDate) {
            this.birthDate = birthDate;
        }
    }
}