清单中的Java验证 [英] Java validation from list

问题描述

如果我有一个类，并且想检查该类中某个属性的输入是否在列表中，我该怎么做?

If I have a class and I want to check if the input to a property in that class is in a list, how would I do this?

示例

public class Length  {

    public static final List<String> ALLOWABLE_UNITS = 
        Collections.unmodifiableList(Arrays.asList("inches", "feet", "meters", "millimeters"));

    public BigDecimal lengthValue;

    @SomeMatchingAnnotation(ALLOWABLE_UNITS)
    public String lengthUnit;
}

是否有注释可以做到这一点?我需要创建自己的吗?

Is there an annotation to do that? Would I have to create my own?

推荐答案

如果您正在使用JSR-303来验证bean，则可以查找一些自定义验证，编写自己的验证，或者仅使用javax.validation.constraints.Pattern:

If you are using JSR-303 to validate your beans then you can look for some custom validations, write yourself one, or just use javax.validation.constraints.Pattern:

@Pattern(message="your message here" , regexp="^(meter|inch|cm)$")
public String lengthUnit;

更新

如果您要传递动态构建的正确值数组，则应该使用自定义验证.如果将Hibernate Validator用作JSR-303提供程序，则可以使用@ScriptAssert批注，该批注允许您使用兼容JSR-223的脚本引擎来定义约束:

If you want to pass dynamically built array of correct values then you should rather use custom validation. If you use Hibernate Validator as JSR-303 provider then you can alternatively use the @ScriptAssert annotation which allows you to define constraints using JSR-223 compatible scripting engine:

@ScriptAssert(lang = "javascript", script = "_this.possibleValues.indexOf(_this.lengthUnit) > -1")

请注意，我没有在上面的示例中运行，但是它应该可以正常工作.

Please note that I did not run above example, but it should work as expected.

或者，您可以在运行中添加约束(仍然假设您使用了休眠验证).

Alternatively you can add constraint in on-the-fly mode (still assuming that you use Hibernate Validation).

ConstraintMapping customMapping = new ConstraintMapping();
customMapping.type(Length.class).property("lengthUnit", FIELD).constraint(new PatternDef().regexp("^(mm|cm|inch)$"));

HibernateValidatorConfiguration cfg = Validation.byProvider(HibernateValidator.class).configure();
cfg.addMapping(customMapping);

ValidatorFactory vf = cfg.buildValidatorFactory();
Validator validator = vf.getValidator()

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