core/src/test/java/org/apache/commons/functor/example/kata/four/IsInteger.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.functor.example.kata.four;

import org.apache.commons.functor.Predicate;

/**
 * Tests to true iff the input object can be converted to
 * an Integer by {@link ToInteger}.
 *
 * @version $Revision$ $Date$
 */
public final class IsInteger implements Predicate<String> {
    public boolean test(String obj) {
        try {
            ToInteger.instance().evaluate(obj);
            return true;
        } catch(RuntimeException e){
            return false;
        }
    }

    public static final IsInteger instance() {
        return INSTANCE;
    }

    private static final IsInteger INSTANCE = new IsInteger();
}