com.vaadin.data.validator.NullValidator Maven / Gradle / Ivy
/*
* Copyright 2000-2014 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.data.validator;
import com.vaadin.data.Validator;
/**
* This validator is used for validating properties that do or do not allow null
* values. By default, nulls are not allowed.
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class NullValidator implements Validator {
private boolean onlyNullAllowed;
private String errorMessage;
/**
* Creates a new NullValidator.
*
* @param errorMessage
* the error message to display on invalidation.
* @param onlyNullAllowed
* Are only nulls allowed?
*/
public NullValidator(String errorMessage, boolean onlyNullAllowed) {
setErrorMessage(errorMessage);
setNullAllowed(onlyNullAllowed);
}
/**
* Validates the data given in value.
*
* @param value
* the value to validate.
* @throws Validator.InvalidValueException
* if the value was invalid.
*/
@Override
public void validate(Object value) throws Validator.InvalidValueException {
if ((onlyNullAllowed && value != null)
|| (!onlyNullAllowed && value == null)) {
throw new Validator.InvalidValueException(errorMessage);
}
}
/**
* Returns true if nulls are allowed otherwise
* false.
*/
public final boolean isNullAllowed() {
return onlyNullAllowed;
}
/**
* Sets if nulls (and only nulls) are to be allowed.
*
* @param onlyNullAllowed
* If true, only nulls are allowed. If false only non-nulls are
* allowed. Do we allow nulls?
*/
public void setNullAllowed(boolean onlyNullAllowed) {
this.onlyNullAllowed = onlyNullAllowed;
}
/**
* Gets the error message that is displayed in case the value is invalid.
*
* @return the Error Message.
*/
public String getErrorMessage() {
return errorMessage;
}
/**
* Sets the error message to be displayed on invalid value.
*
* @param errorMessage
* the Error Message to set.
*/
public void setErrorMessage(String errorMessage) {
this.errorMessage = errorMessage;
}
}