diff options
Diffstat (limited to 'runtime/src/main/java/org/onap/policy/clamp/clds/util/ResourceFileUtils.java')
| -rw-r--r-- | runtime/src/main/java/org/onap/policy/clamp/clds/util/ResourceFileUtils.java | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/runtime/src/main/java/org/onap/policy/clamp/clds/util/ResourceFileUtils.java b/runtime/src/main/java/org/onap/policy/clamp/clds/util/ResourceFileUtils.java new file mode 100644 index 000000000..d6184c656 --- /dev/null +++ b/runtime/src/main/java/org/onap/policy/clamp/clds/util/ResourceFileUtils.java @@ -0,0 +1,89 @@ +/*- + * ============LICENSE_START======================================================= + * ONAP POLICY-CLAMP + * ================================================================================ + * Copyright (C) 2017, 2021 AT&T Intellectual Property. All rights + * reserved. + * ================================================================================ + * 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. + * ============LICENSE_END============================================ + * =================================================================== + * + */ + +package org.onap.policy.clamp.clds.util; + +import java.io.IOException; +import java.io.InputStream; +import java.util.Scanner; + +/** + * Utility methods supporting resources accesses. + */ +public final class ResourceFileUtils { + + /** + * getResourceAsStram supports the "file:" prefix as they use URL. + * So here we want to eliminate classpath: prefix, so that this class can get + * files from jar resource or file system. + */ + + private static final String CLASSPATH_PREFIX = "classpath:"; + + /** + * Private constructor to avoid creating instances of util class. + */ + private ResourceFileUtils() { + } + + /** + * Method to access a file from the jar resource folder or file system. + * Give the prefix "classpath:" so that it accesses the jar resource folder (default case) + * or the prefix "file:" so that it accesses the file system. + * + * @param fileName The path of the resource (no prefix it will be a classpath access, + * "classpath:/myfilename" or "file:/myfilename") + * @return The file as inputStream + */ + public static InputStream getResourceAsStream(String fileName) { + InputStream is = Thread.currentThread().getContextClassLoader() + .getResourceAsStream(fileName.replaceFirst("^" + CLASSPATH_PREFIX, "")); + if (is == null) { + throw new IllegalArgumentException("Unable to find resource: " + fileName); + } + return is; + } + + /** + * Method to access a resource file as a string. + * Give the prefix "classpath:" so that it accesses the jar resource folder (default case) + * or the prefix "file:" so that it accesses the file system. + * + * @param fileName The path of the resource (no prefix it will be a classpath access, + * "classpath:/myfilename" or "file:/myfilename") + * @return The file as String + * @throws IOException In case of failure to find the file. + */ + public static String getResourceAsString(String fileName) throws IOException { + try (InputStream is = getResourceAsStream(fileName)) { + return streamToString(is); + } + } + + private static String streamToString(InputStream inputStream) { + try (Scanner scanner = new Scanner(inputStream)) { + Scanner delimitedScanner = scanner.useDelimiter("\\A"); + return delimitedScanner.hasNext() ? delimitedScanner.next() : ""; + } + } +}
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