约束不起作用的椭圆激活规则

Question

public class BusinessObject
{
    private String fieldA;

    @NotNull(when = "groovy:_this.fieldA != null")
    private String fieldB;
}

public class BusinessObject {
    private String fieldA;

    //@NotNull(when = "groovy:_this.fieldA != null") //works for public & private
    @NotNull(when = "javascript:_this.fieldA != null") //only works when fieldA is public
    private String fieldB;

    public BusinessObject(){}

    public BusinessObject(String fieldA, String fieldB) {
        this.fieldA = fieldA;
        this.fieldB = fieldB;
    }
}

构造函数验证的代码：

@Guarded
public class BusinessObjectConstructorValidation {
    private String fieldA;
    private String fieldB;

    public BusinessObjectConstructorValidation(
            String fieldA,
            @NotNull(when = "groovy:_this.fieldA != null") String fieldB) {

        this.fieldA = fieldA;
        this.fieldB = fieldB;
    }
}

如何测试对象：

public class BusinessObjectTest {

    @Test
    public void fieldANullFieldBNotValidatedNoViolations() {
        BusinessObject businessObject = new BusinessObject(null, null);
        Validator validator = new Validator();
        validator.validate(businessObject);
    }

    //This test will fail if the fields are private and using javascript
    //If it's public or using groovy it passes
    @Test
    public void fieldANotNullFieldBValidatedViolationsSizeIsOne() {
        BusinessObject businessObject = new BusinessObject("A", null);
        Validator validator = new Validator();
        List<ConstraintViolation> errors = validator.validate(businessObject);
        System.out.println(errors.size());
        assertThat(errors.size(), is(1));
    }

    @Test
    public void fieldANullFieldBNotNullNoViolations() {
        BusinessObject businessObject = new BusinessObject(null, "B");
        Validator validator = new Validator();
        validator.validate(businessObject);
    }
}

我不知道为什么JavaScript版本与groovy版本的行为不同，我已经尝试更改了我能想到的所有组合，包括:_this.fielda、__this.fielda、__this.fielda、Window.fielda、__fielda和__fielda

Answer 1

我通过执行以下操作解决了这个问题，并按照开发人员的建议切换到groovy而不是JavaScript。

JavaScript引擎Rhino不能直接访问私有字段。例如。类似“JavaScript:_this.MyPrivateField！=null&&_this.MyPrivateField.length>10”的内容将始终返回false，而不管私有字段的值如何。如果Rhino不能访问私有字段，它显然不会引发异常。

我建议您使用groovy而不是javascript来激活约束。对于大多数脚本运行时（包括JavaScript)，语句_this.SomeVariable将导致调用_this.getSomeVariable（）getter，而不是直接访问同名的私有字段。

不幸的是，在构造函数中添加验证是不起作用的，正如我在问题中发布的那样。因此，为了解决这个问题，我需要将验证添加到字段中，并将@PostValidateThis注释添加到构造函数中。

调用构造函数后使用验证的示例Pojo。

@Guarded(checkInvariants = false)// removing this results in StackOverflowError
public class User {
    private final String firstName;
    private final String lastName;
    @NotNull(when = "groovy:_this.lastName != null")
    private final Integer age;

    @PostValidateThis
    public User(String firstName, String lastName, Integer age) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.age = age;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public Integer getAge() {
        return age;
    }
}

对上述POJO进行基本单元测试。

public class UserTest {
    @Test
    public void userValidParamsNoException() throws Exception {
        User user = new User("foo","bar",123);
        assertThat(user, is(not(nullValue())));
        assertThat(user.getFirstName(), is("foo"));
        assertThat(user.getLastName(), is("bar"));
        assertThat(user.getAge(), is(123));
    }

    @Test
    public void userLastNameNullNoException() throws Exception {
        User user = new User("foo",null, null);
        assertThat(user, is(not(nullValue())));
        assertThat(user.getFirstName(), is("foo"));
    }

    @Test(expected = ConstraintsViolatedException.class)
    public void userLastNameNotNullAgeNullThrowsException() throws Exception {
        User user = new User("foo","bar", null);
    }
}