SomePojoValidatorTest.java unit test for Hibernate Validator

SomePojoValidatorTest.java

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

import java.util.Locale;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.Length;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class SomePojoTest {
    class SomePojo {
        private String text;

        @NotNull
        @Length(max = 100)
        public String getText() {
            return text;
        }

        public void setText(String text) {
            this.text = text;
        }
    }

    static Validator validator;

    @BeforeClass
    public static void before() throws Exception {
        Locale.setDefault(Locale.ENGLISH);
        ValidatorFactory config = Validation.buildDefaultValidatorFactory();
        validator = config.getValidator();
    }

    Set<ConstraintViolation<SomePojo>> constraintViolations;

    SomePojo somePojo;

    @Before
    public void setUp() throws Exception {
        somePojo = new SomePojo();
        somePojo.setText("XXX-ValidInputValue-XXX");
    }

    @Test
    public void shouldFailValidationWithNullInputValuesForTextField() {
        constraintViolations = validator.validateValue(SomePojo.class, "text", null);
        assertThat("Text field should have a validation error for null input", constraintViolations.size(), is(1));
        assertThat(constraintViolations.iterator().next().getMessage(), is("may not be null"));
    }

    @Test
    public void shouldFailValidationWithOverLongInputValuesForTextField() {
        // create a string made up of maxLength + 1 copies of the String "X"
        String inputValue = String.format("%0" + 101 + "d", 0).replace("0", "X");
        constraintViolations = validator.validateValue(SomePojo.class, "text", inputValue);
        assertThat("Should Not get validation errors - input: " + inputValue + " issues: " + constraintViolations,
                constraintViolations.size(), is(1));
    }

    @Test
    public void shouldPassLengthValidationPropertyInputValuesForTextField() {
        String inputValue = "SomeText";
        constraintViolations = validator.validateValue(SomePojo.class, "text", inputValue);
        assertThat("Should have got a validation error - input: " + inputValue, constraintViolations.size(), is(0));
    }

    @Test
    public void testHappyPathValidationForWholeObject() {
        constraintViolations = validator.validate(somePojo);
        assertThat("validation failed: " + constraintViolations, constraintViolations.size(), is(0));

    }

}