我可以更改Method参数的ConstraintValidator中的属性路径吗？ [英] Can I change the property path in a ConstraintValidator for Method arguments?
问题描述
如果您熟悉Bean Validation Framework，那么您知道无法获取方法参数的名称。因此，如果对方法的第一个参数执行@NotNull约束，并且验证失败，则getPropertyPath将类似于arg1。
我想创建我自己的@NotNull版本， @NamedNotNull（emailAddress）。但我无法弄清楚如何覆盖我的Validator中的#getPropertyPath？有没有办法做到这一点，或者我坚持arg1或arg2等。
编辑
基于我收到的答案，我能够想出以下实现，它允许我从@QueryParam或@PathParam注释中获取值，并将它们用作Bean的属性路径验证注释，如@NotNull。
对于Jersey，您需要创建以下类。注意DefaultParameterNameProvider的实现：
public class ValidationConfigurationContextResolver implements ContextResolver< ValidationConfig> {
@Override
public ValidationConfig getContext（final Class<> type）{
final ValidationConfig config = new ValidationConfig（）;
config.parameterNameProvider（new RestAnnotationParameterNameProvider（））;
return config;
}
static class RestAnnotationParameterNameProvider extends DefaultParameterNameProvider {
@Override
public List< String> getParameterNames（方法方法）{
Annotation [] [] annotationsByParam = method.getParameterAnnotations（）;
列表< String> names = new ArrayList<>（annotationsByParam.length）; （Annotation [] annotations：annotationsByParam）
{
String name = getParamName（annotations）;
if（name == null）
name =arg+（names.size（）+ 1）;
names.add（name）;
}
返回名称;
$ b $ private static String getParamName（Annotation [] annotations）{
for（Annotation annotation：annotations）{
if（annotation.annotationType（）== QueryParam .class）{
return QueryParam.class.cast（annotation）.value（）;
}
else if（annotation.annotationType（）== PathParam.class）{
return PathParam.class.cast（annotation）.value（）;
}
}
返回null;
$ b $ / code> 然后在你的RestConfig中，你需要添加以下行：
register（ValidationConfigurationContextResolver.class）;
就是这样。现在你的ConstraintValidationExceptions将包含它们被注释的QueryParam或PathParam的名字。例如：
public void getUser（
@NotNull @QueryParam（emailAddress）String emailAddress，
@NotNull @QueryParam（password）字符串密码）
{...}
Bean Validation 1.1引入了 ParameterNameProvider 接口用于在创建约束冲突对象时提供方法和构造函数参数的名称。
Hibernate Validator 5.2引入了 Dropwizard对其进行了扩展，并使用 @XxxParam ReflectionParameterNameProvider class，a ParameterNameProvider 的实现使用反射来获取实际的参数名称（要正常工作，它需要使用参数编译类 / ** 注释的支持/apidocs/io/dropwizard/jersey/validation/JerseyParameterNameProvider.htmlrel =nofollow noreferrer>
*使用Java 8反射来获取参数名称。
*< p>
*< p>对于此提供程序返回实际参数名称，必须使用'-parameters'编译器
*参数编译类。否则，JDK将以{@code arg0}，{@code arg1}等形式返回合成名称。< / p>
*< p>
*< p>请参阅< a href =http://openjdk.java.net/jeps/118> JEP 118< / a>< / p>
*
* @author Khalid Alqinyah
* @since 5.2
* /
public class ReflectionParameterNameProvider implements ParameterNameProvider {
@Override
public List< String> getParameterNames（构造函数<？>构造函数）{
return getParameterNames（constructor.getParameters（））;
}
@Override
public List< String> getParameterNames（Method method）{
return getParameterNames（method.getParameters（））;
}
私人列表< String> getParameterNames（Parameter [] parameters）{
List< String> parameterNames = newArrayList（）;
for（Parameter parameter：parameters）{
//如果在编译时使用'-parameters'，将返回实际名称。否则，它将是arg0，arg1 ...
parameterNames.add（parameter.getName（））;
}
return parameterNames;
$ / code $ / pre
$ hr
JerseyParameterNameProvider ，它也可以与其他JAX-RS实现一起工作：
/ **
*在hibernate验证器中为参数名称发现添加球衣支持。
*< p>
*< p>这个提供程序的行为与Hibernate提供的{@link ReflectionParameterNameProvider}行为相似，除非
*方法参数使用球衣参数注释进行注释，如{@link QueryParam}。如果球衣参数
*注释存在，则注释的值将用作参数名称。< / p>
* /
public class JerseyParameterNameProvider extends ReflectionParameterNameProvider {
@Override
public List< String> getParameterNames（Method method）{
Parameter [] parameters = method.getParameters（）;
Annotation [] [] parameterAnnotations = method.getParameterAnnotations（）;
列表< String> names = new ArrayList<>（parameterAnnotations.length）;
for（int i = 0; i< parameterAnnotations.length; i ++）{
Annotation [] annotations = parameterAnnotations [i];
String name = getParameterNameFromAnnotations（annotations）.orElse（parameters [i] .getName（））;
names.add（name）;
}
返回名称;
}
/ **
*从其注释中派生成员的名称和类型
* /
public static可选< String> getParameterNameFromAnnotations（Annotation [] memberAnnotations）{
$ b $ for（Annotation a：memberAnnotations）{
if（QueryParam的一个实例）{
return Optional.of（query param+（ （QueryParam）a）.value（））;
} else if（PathParam的一个实例）{
return Optional.of（path param+（（PathParam）a）.value（））;
} else if（HeaderParam的一个实例）{
return Optional.of（header+（（HeaderParam）a）.value（））;
} else if（CookieParam的一个实例）{
return Optional.of（cookie+（（CookieParam）a）.value（））;
} else if（FormParam的一个实例）{
return Optional.of（form field+（（FormParam）a）.value（））;
} else if（一个Context的实例）{
return Optional.of（context）;
} else if（一个MatrixParam的实例）{
return Optional.of（matrix param+（（MatrixParam）a）.value（））;
}
}
return Optional.empty（）;
$ b如果你不使用Dropwizard，你可以使用上面的代码来创建你自己的实现。
定制 Validator 用于验证Jersey资源类/方法可以使用 ValidationConfig 类，并通过 ContextResolver< T> 机制：
public class ValidationConfigurationContextResolver
implements ContextResolver< ValidationConfig> {
@Override
public ValidationConfig getContext（final Class<？> type）{
ValidationConfig config = new ValidationConfig（）;
config.parameterNameProvider（new CustomParameterNameProvider（））;
return config;
$ / code>
然后注册 ValidationConfigurationContextResolver in ResourceConfig 。
请参阅有关Bean验证支持的Jersey文档以获取更多详细信息。
If you are familiar with the Bean Validation Framework you know that you cannot get the name of a method argument. So if you do a @NotNull constraint on the first argument of a method and the validation fails the getPropertyPath will be something like "arg1".
I would like to create my own version of @NotNull that can take a value e.g. @NamedNotNull( "emailAddress" ). But I can't figure out how to override the #getPropertyPath in my Validator? Is there any way to do this or am I stuck with "arg1" or "arg2", etc.
EDIT
Based on the answer I received I was able to come up with the following implementation that allows me to take the value from my @QueryParam or @PathParam annotations and use those as the property path for Bean Validation annotations like @NotNull.
For Jersey you need to create the following class. Note the implementation of DefaultParameterNameProvider:
public class ValidationConfigurationContextResolver implements ContextResolver<ValidationConfig> {
@Override
public ValidationConfig getContext( final Class<?> type ) {
final ValidationConfig config = new ValidationConfig();
config.parameterNameProvider( new RestAnnotationParameterNameProvider() );
return config;
}
static class RestAnnotationParameterNameProvider extends DefaultParameterNameProvider {
@Override
public List<String> getParameterNames( Method method ) {
Annotation[][] annotationsByParam = method.getParameterAnnotations();
List<String> names = new ArrayList<>( annotationsByParam.length );
for ( Annotation[] annotations : annotationsByParam ) {
String name = getParamName( annotations );
if ( name == null )
name = "arg" + ( names.size() + 1 );
names.add( name );
}
return names;
}
private static String getParamName( Annotation[] annotations ) {
for ( Annotation annotation : annotations ) {
if ( annotation.annotationType() == QueryParam.class ) {
return QueryParam.class.cast( annotation ).value();
}
else if ( annotation.annotationType() == PathParam.class ) {
return PathParam.class.cast( annotation ).value();
}
}
return null;
}
}
}
Then in your RestConfig you need to add the following line:
register( ValidationConfigurationContextResolver.class );
That's it. Now your ConstraintValidationExceptions will contain the name of the QueryParam or PathParam they are annotated with. For example:
public void getUser(
@NotNull @QueryParam( "emailAddress" ) String emailAddress,
@NotNull @QueryParam( "password" ) String password )
{ ... }
解决方案 Bean Validation 1.1 introduced the ParameterNameProvider interface for providing names for method and constructor parameters when creating constraint violation objects.
Hibernate Validator 5.2 introduced the ReflectionParameterNameProvider class, a ParameterNameProvider implementation that uses reflection to get the actual parameter names (to work properly, it requires the classes to be compiled with the -parameters compiler argument):
/**
* Uses Java 8 reflection to get the parameter names.
* <p>
* <p>For this provider to return the actual parameter names, classes must be compiled with the '-parameters' compiler
* argument. Otherwise, the JDK will return synthetic names in the form {@code arg0}, {@code arg1}, etc.</p>
* <p>
* <p>See also <a href="http://openjdk.java.net/jeps/118">JEP 118</a></p>
*
* @author Khalid Alqinyah
* @since 5.2
*/
public class ReflectionParameterNameProvider implements ParameterNameProvider {
@Override
public List<String> getParameterNames(Constructor<?> constructor) {
return getParameterNames(constructor.getParameters());
}
@Override
public List<String> getParameterNames(Method method) {
return getParameterNames(method.getParameters());
}
private List<String> getParameterNames(Parameter[] parameters) {
List<String> parameterNames = newArrayList();
for (Parameter parameter : parameters) {
// If '-parameters' is used at compile time, actual names will be returned. Otherwise, it will be arg0, arg1...
parameterNames.add(parameter.getName());
}
return parameterNames;
}
}
Dropwizard extends it and add support to JAX-RS @XxxParam annotations with the JerseyParameterNameProvider that should work with other JAX-RS implementations too:
/**
* Adds jersey support to parameter name discovery in hibernate validator.
* <p>
* <p>This provider will behave like the hibernate-provided {@link ReflectionParameterNameProvider} except when a
* method parameter is annotated with a jersey parameter annotation, like {@link QueryParam}. If a jersey parameter
* annotation is present the value of the annotation is used as the parameter name.</p>
*/
public class JerseyParameterNameProvider extends ReflectionParameterNameProvider {
@Override
public List<String> getParameterNames(Method method) {
Parameter[] parameters = method.getParameters();
Annotation[][] parameterAnnotations = method.getParameterAnnotations();
List<String> names = new ArrayList<>(parameterAnnotations.length);
for (int i = 0; i < parameterAnnotations.length; i++) {
Annotation[] annotations = parameterAnnotations[i];
String name = getParameterNameFromAnnotations(annotations).orElse(parameters[i].getName());
names.add(name);
}
return names;
}
/**
* Derives member's name and type from it's annotations
*/
public static Optional<String> getParameterNameFromAnnotations(Annotation[] memberAnnotations) {
for (Annotation a : memberAnnotations) {
if (a instanceof QueryParam) {
return Optional.of("query param " + ((QueryParam) a).value());
} else if (a instanceof PathParam) {
return Optional.of("path param " + ((PathParam) a).value());
} else if (a instanceof HeaderParam) {
return Optional.of("header " + ((HeaderParam) a).value());
} else if (a instanceof CookieParam) {
return Optional.of("cookie " + ((CookieParam) a).value());
} else if (a instanceof FormParam) {
return Optional.of("form field " + ((FormParam) a).value());
} else if (a instanceof Context) {
return Optional.of("context");
} else if (a instanceof MatrixParam) {
return Optional.of("matrix param " + ((MatrixParam) a).value());
}
}
return Optional.empty();
}
}
If you don't use Dropwizard, you can use the above code to create your own implementation.
Customization of the Validator used in validation of Jersey resource classes/methods can be done using ValidationConfig class and exposing it via ContextResolver<T> mechanism:
public class ValidationConfigurationContextResolver
implements ContextResolver<ValidationConfig> {
@Override
public ValidationConfig getContext(final Class<?> type) {
ValidationConfig config = new ValidationConfig();
config.parameterNameProvider(new CustomParameterNameProvider());
return config;
}
}
Then register the ValidationConfigurationContextResolver in ResourceConfig.
Refer to the Jersey documentation about Bean Validation support for more details.
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