net.sourceforge.pmd.properties.constraints.ConstraintFactory.java Source code

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Here is the source code for net.sourceforge.pmd.properties.constraints.ConstraintFactory.java

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/**
 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
 */

package net.sourceforge.pmd.properties.constraints;

import org.apache.commons.lang3.StringUtils;

import net.sourceforge.pmd.annotation.Experimental;

/**
 * Transitional class until we move to Java 8.
 * Used to build a validator until we move the static factory on the interface. Do not use.
 *
 * @author Clment Fournier
 * @since 6.10.0
 */
@Experimental
final class ConstraintFactory {

    private ConstraintFactory() {

    }

    /**
     * Builds a new validator from a predicate, and description.
     *
     * @param pred                  The predicate. If it returns
     *                              false on a value, then the
     *                              value is deemed to have a
     *                              problem
     * @param constraintDescription Description of the constraint,
     *                              see {@link PropertyConstraint#getConstraintDescription()}.
     * @param <U>                   Type of value to validate
     *
     * @return A new validator
     */
    @Experimental
    public static <U> PropertyConstraint<U> fromPredicate(final Predicate<? super U> pred,
            final String constraintDescription) {
        return new PropertyConstraint<U>() {

            @Override
            public boolean test(U value) {
                return pred.test(value);
            }

            // TODO message could be better, eg include name of the property
            @Override
            public String validate(U value) {
                return pred.test(value) ? null
                        : "Constraint violated on property value '" + value + "' (" + constraintDescription + ")";
            }

            @Override
            public String getConstraintDescription() {
                return StringUtils.capitalize(constraintDescription);
            }

            @Override
            public PropertyConstraint<Iterable<? extends U>> toCollectionConstraint() {
                final PropertyConstraint<U> thisValidator = this;
                return ConstraintFactory
                        .<Iterable<? extends U>>fromPredicate(new Predicate<Iterable<? extends U>>() {
                            @Override
                            public boolean test(Iterable<? extends U> us) {
                                for (U u : us) {
                                    if (!thisValidator.test(u)) {
                                        return false;
                                    }
                                }
                                return true;
                            }
                        }, "Components " + StringUtils.uncapitalize(thisValidator.getConstraintDescription()));
            }
        };
    }

    // Until we have Java 8
    public interface Predicate<T> {
        boolean test(T t);
    }
}