我正在嘗試驗證 Spring Boot 中兩個字段之一是否不為空？我在主對象的方法類中設(shè)置了它：@NotNull(message = "Username field is required")private String username;@NotNull(message = "Email field is required")private String email;但這需要兩個字段都不為空。然后我使用此處描述的自定義驗證https://lmonkiewicz.com/programming/get-noticed-2017/spring-boot-rest-request-validation/但我無法讓該示例正常工作。我必須堅持用戶類聲明：@CombinedNotNull(fields = {"username","email"})public class User implements { private long id = 0L; @NotNull(message = "First name field is required") private String firstName; @NotNull(message = "Last name field is required") private String lastName; private String username; private String email; @NotNull(message = "Status field is required") private String status; ...all methods here... ...setters and getters...}CombibnedNotNull 類：@Documented@Retention(RUNTIME)@Target({ TYPE, ANNOTATION_TYPE })@Constraint(validatedBy = userValidator.class)public @interface CombinedNotNull { String message() default "username or email is required"; Class<?>[] groups() default { }; Class<? extends Payload>[] payload() default { };}用戶驗證器類：@Componentpublic class userValidator implements ConstraintValidator<CombinedNotNull, User> { @Override public void initialize(final CombinedNotNull combinedNotNull) { fields = combinedNotNull.fields(); } @Override public boolean isValid(final User user, final ConstraintValidatorContext context) { final BeanWrapperImpl beanWrapper = new BeanWrapperImpl(user); for (final String f : fields) { final Object fieldValue = beanWrapper.getPropertyValue(f); if (fieldValue == null) { return false; } } return true; }}有沒有其他方法可以完成這項工作，或者我應(yīng)該使用該頁面中的“復(fù)雜”示例？
3 回答
一只斗牛犬
TA貢獻(xiàn)1784條經(jīng)驗 獲得超2個贊
我假設(shè)username OR email不能為空。不是異或。
在類中添加這個 getter User：
@AssertTrue(message = "username or email is required")
private boolean isUsernameOrEmailExists() {
return username != null || email != null;
}
根據(jù)我的經(jīng)驗，方法名稱必須遵循 getter 名稱約定，否則這將不起作用。例如，getFoo或isBar。
這有一個小問題：此驗證錯誤的字段名稱將是usernameOrEmailExists，只有 1 個錯誤字段。如果這不是問題，這可能會有所幫助。
但是，如果您想在發(fā)生錯誤時擁有username和email字段，則可以使用此解決方法：
public String getUsername() {
return username;
}
public String getEmail() {
return email;
}
@AssertTrue(message = "username or email is required")
private boolean isUsername() {
return isUsernameOrEmailExists();
}
@AssertTrue(message = "username or email is required")
private boolean isEmail() {
return isUsernameOrEmailExists();
}
private boolean isUsernameOrEmailExists() {
return username != null || email != null;
}
get...方法只是一般用途的簡單吸氣劑，is... 用于驗證。這將發(fā)出 2 個帶有username和email字段的驗證錯誤。
皈依舞
TA貢獻(xiàn)1851條經(jīng)驗 獲得超3個贊
我會嘗試為您實現(xiàn)它（即使我沒有 IDE）。
在里面ConstraintValidator#initialize你可以得到配置字段的名稱，這些名稱不能是null.
@Override
public void initialize(final CombinedNotNull combinedNotNull) {
fields = combinedNotNull.fields();
}
在里面ConstraintValidator#isValid，您可以使用這些字段的名稱來檢查Object字段。
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context) {
final BeanWrapperImpl beanWrapper = new BeanWrapperImpl(value);
for (final String f : fields) {
final Object fieldValue = beanWrapper.getPropertyValue(f);
if (fieldValue == null) {
return false;
}
}
return true;
}
注解：
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
@Retention(RUNTIME)
@Target({ElementType.TYPE, ElementType.ANNOTATION_TYPE})
@Constraint(validatedBy = CombinedNotNullValidator.class)
public @interface CombinedNotNull {
String message() default "username or email is required";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
/**
* Fields to validate against null.
*/
String[] fields() default {};
}
注釋可以應(yīng)用為
@CombinedNotNull(fields = {
"fieldName1",
"fieldName2"
})
public class MyClassToValidate { ... }
要了解如何創(chuàng)建類級約束注釋，請始終參考官方文檔。文檔
SMILET
TA貢獻(xiàn)1796條經(jīng)驗 獲得超4個贊
如果您想驗證是否設(shè)置了一個而其他的為空：
注解
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
@Retention(RUNTIME)
@Target({ElementType.TYPE, ElementType.ANNOTATION_TYPE})
@Constraint(validatedBy = OneNotNullValidator.class)
public @interface OneNotNull {
String message() default "Exactly one of the fields must be set and the other must be null";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
/**
* Fields to validate against null.
*/
String[] fields() default {};
}
驗證器
import java.util.Arrays;
import java.util.Objects;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.stereotype.Component;
@Component
public class OneNotNullValidator implements ConstraintValidator<OneNotNull, Object> {
private String[] fields;
@Override
public void initialize(final OneNotNull combinedNotNull) {
fields = combinedNotNull.fields();
}
@Override
public boolean isValid(final Object obj, final ConstraintValidatorContext context) {
final BeanWrapperImpl beanWrapper = new BeanWrapperImpl(obj);
return Arrays.stream(fields)
.map(beanWrapper::getPropertyValue)
.filter(Objects::isNull)
.count()
== 1;
}
}
用法
@OneNotNull(
fields = {"username","email"},
message="Either username or email must be set"
)
public class User {
private String username;
private String email;
// ...
}
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