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}