001/*
002 * Copyright (C) 2023-present The Prometheus jmx_exporter Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package io.prometheus.jmx.common.configuration;
018
019import io.prometheus.jmx.common.util.Precondition;
020import java.util.function.Function;
021import java.util.function.Supplier;
022
023/**
024 * Class to validate a String is not blank, throwing a RuntimeException from the Supplier if there
025 * is a ClassCastException
026 */
027public class ValidateStringIsNotBlank implements Function<String, String> {
028
029    private final Supplier<? extends RuntimeException> supplier;
030
031    /**
032     * Constructor
033     *
034     * @param supplier supplier
035     */
036    public ValidateStringIsNotBlank(Supplier<? extends RuntimeException> supplier) {
037        Precondition.notNull(supplier);
038        this.supplier = supplier;
039    }
040
041    /**
042     * Method to apply a function
043     *
044     * @param value value
045     * @return the return value
046     */
047    @Override
048    public String apply(String value) {
049        if (value.trim().isEmpty()) {
050            throw supplier.get();
051        }
052
053        return value;
054    }
055}