1 files changed, 135 insertions, 0 deletions
diff --git a/infra/minimal-distribution-core/src/main/java/io/fd/honeycomb/infra/distro/schema/ResourceLoader.java b/infra/minimal-distribution-core/src/main/java/io/fd/honeycomb/infra/distro/schema/ResourceLoader.java
new file mode 100644
index 000000000..c851dab1b
--- /dev/null
+++ b/infra/minimal-distribution-core/src/main/java/io/fd/honeycomb/infra/distro/schema/ResourceLoader.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ *
+ * 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.
+ */
+
+package io.fd.honeycomb.infra.distro.schema;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static java.lang.String.format;
+
+import com.google.common.base.Charsets;
+import com.google.common.base.Strings;
+import com.google.common.io.Resources;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.stream.Collectors;
+import org.apache.commons.io.IOUtils;
+
+interface ResourceLoader {
+
+    default Set<String> loadResourceContentsOnPath(final String path) {
+        final URL folderUrl = getClass().getClassLoader().getResource(path);
+        checkNotNull(folderUrl, "Resources %s not found", path);
+
+        if (ResourceLoaderIml.urlToUri(folderUrl).getScheme().equals("jar")) {
+            return ResourceLoaderIml.readFromJar(path, folderUrl);
+        } else {
+            return ResourceLoaderIml.readFromFolder(folderUrl);
+        }
+
+    }
+
+    final class ResourceLoaderIml {
+
+        private static Set<String> readFromFolder(final URL folderUrl) {
+            final File folder = new File(folderUrl.getPath());
+            final File[] files = checkNotNull(folder.listFiles(), "No files present on path %s", folderUrl);
+            return Arrays.stream(files)
+                    .map(ResourceLoaderIml::fileToUrl)
+                    .map(ResourceLoaderIml::urlToContentString)
+                    .flatMap(content -> Arrays.stream(content.split(System.lineSeparator())))
+                    .filter(ResourceLoaderIml::filterNonEmpty)
+                    .collect(Collectors.toSet());
+        }
+
+        private static Set<String> readFromJar(final String path, final URL url) {
+            final String uriString = urlToUri(url).toString();
+            final String fileReference = extractJarFilePath(uriString);
+            try (JarFile jar = new JarFile(new File(fileReference))) {
+                return Collections.list(jar.entries())
+                        .stream()
+                        .filter(jarEntry -> jarEntry.getName().contains(path))
+                        .map(jarEntry -> getJarEntryStream(jar, jarEntry))
+                        .map(ResourceLoaderIml::readJarEntryStream)
+                        .flatMap(content -> Arrays.stream(content.split(System.lineSeparator())))
+                        .filter(ResourceLoaderIml::filterNonEmpty)
+                        .collect(Collectors.toSet());
+            } catch (IOException e) {
+                throw new IllegalStateException(e);
+            }
+        }
+
+        private static String extractJarFilePath(final String uriString) {
+            return uriString.substring(0, uriString.indexOf("!")).replace("jar:file:", "");
+        }
+
+        private static boolean filterNonEmpty(final String line) {
+            return !Strings.isNullOrEmpty(line.trim());
+        }
+
+        private static String readJarEntryStream(final InputStream inputStream) {
+            try {
+                final String value = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
+                IOUtils.closeQuietly(inputStream);
+                return value;
+            } catch (IOException e) {
+                throw new IllegalStateException(e);
+            }
+        }
+
+        private static InputStream getJarEntryStream(final JarFile jar, final JarEntry jarEntry) {
+            try {
+                return jar.getInputStream(jarEntry);
+            } catch (IOException e) {
+                throw new IllegalStateException(format("Unable to get stream for entry %s | jar %s", jar, jarEntry));
+            }
+        }
+
+        private static URI urlToUri(final URL url) {
+            try {
+                return url.toURI();
+            } catch (URISyntaxException e) {
+                throw new IllegalStateException(format("Unable to convert URL %s to URI", url));
+            }
+        }
+
+        private static String urlToContentString(final URL url) {
+            try {
+                return Resources.toString(url, Charsets.UTF_8);
+            } catch (IOException e) {
+                throw new IllegalArgumentException("Unable to read resource from: " + url, e);
+            }
+        }
+
+        private static URL fileToUrl(final File file) {
+            try {
+                return file.toURI().toURL();
+            } catch (MalformedURLException e) {
+                throw new IllegalStateException(e);
+            }
+        }
+    }
+}