Start splitting into maven modules

1 files changed, 181 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/components/FileComponentRepository.java b/base/src/main/java/bjc/utils/components/FileComponentRepository.java
new file mode 100644
index 0000000..efde5c7
--- /dev/null
+++ b/base/src/main/java/bjc/utils/components/FileComponentRepository.java
@@ -0,0 +1,181 @@
+package bjc.utils.components;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.function.BiPredicate;
+import java.util.function.Function;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import bjc.utils.data.IHolder;
+import bjc.utils.data.Identity;
+import bjc.utils.funcdata.FunctionalMap;
+import bjc.utils.funcdata.IList;
+import bjc.utils.funcdata.IMap;
+import bjc.utils.funcutils.FileUtils;
+
+/**
+ * A component repository that loads its components from files in a directory
+ *
+ * @author ben
+ *
+ * @param <ComponentType>
+ *                The type of component being read in
+ */
+public class FileComponentRepository<ComponentType extends IDescribedComponent>
+		implements IComponentRepository<ComponentType> {
+	// The logger to use for storing data about this class
+	private static final Logger CLASS_LOGGER = Logger.getLogger("FileComponentRepository");
+
+	// The internal storage of components
+	private IMap<String, ComponentType> components;
+
+	// The path that all the components came from
+	private Path sourceDirectory;
+
+	/**
+	 * Create a new component repository sourcing components from files in a
+	 * directory
+	 *
+	 * An exception thrown during the loading of a component will only cause
+	 * the loading of that component to fail, but a warning will be logged.
+	 *
+	 * @param directory
+	 *                The directory to read component files from
+	 * @param componentReader
+	 *                The function to use to convert files to components
+	 */
+	public FileComponentRepository(final File directory,
+			final Function<File, ? extends ComponentType> componentReader) {
+		// Make sure we have valid arguments
+		if (directory == null)
+			throw new NullPointerException("Directory must not be null");
+		else if (!directory.isDirectory())
+			throw new IllegalArgumentException("File " + directory + " is not a directory.\n"
+					+ "Components can only be read from a directory");
+		else if (componentReader == null) throw new NullPointerException("Component reader must not be null");
+
+		// Initialize our fields
+		components = new FunctionalMap<>();
+		sourceDirectory = directory.toPath().toAbsolutePath();
+
+		// Marker for making sure we don't skip the parent
+		final IHolder<Boolean> isFirstDir = new Identity<>(true);
+
+		// Predicate to use to traverse all the files in a directory,
+		// but
+		// not recurse into sub-directories
+		final BiPredicate<Path, BasicFileAttributes> firstLevelTraverser = (pth, attr) -> {
+			if (attr.isDirectory() && !isFirstDir.getValue()) /*
+										 * Skip
+										 * directories,
+										 * they
+										 * probably
+										 * have
+										 * component
+										 * support
+										 * files.
+										 */
+				return false;
+
+			/*
+			 * Don't skip the first directory, that's the parent
+			 * directory
+			 */
+			isFirstDir.replace(false);
+
+			return true;
+		};
+
+		// Try reading components
+		try {
+			FileUtils.traverseDirectory(sourceDirectory, firstLevelTraverser, (pth, attr) -> {
+				loadComponent(componentReader, pth);
+
+				// Keep loading components, even if this one
+				// failed
+				return true;
+			});
+		} catch (final IOException ioex) {
+			CLASS_LOGGER.log(Level.WARNING, ioex, () -> "Error found reading component from file.");
+		}
+	}
+
+	@Override
+	public IMap<String, ComponentType> getAll() {
+		return components;
+	}
+
+	@Override
+	public ComponentType getByName(final String name) {
+		return components.get(name);
+	}
+
+	@Override
+	public IList<ComponentType> getList() {
+		return components.valueList();
+	}
+
+	@Override
+	public String getSource() {
+		return "Components read from directory " + sourceDirectory + ".";
+	}
+
+	/*
+	 * Load a component from a file
+	 */
+	private void loadComponent(final Function<File, ? extends ComponentType> componentReader, final Path pth) {
+		try {
+			// Try to load the component
+			final ComponentType component = componentReader.apply(pth.toFile());
+
+			if (component == null)
+				throw new NullPointerException("Component reader read null component");
+			else if (!components.containsKey(component.getName())) {
+				// We only care about the latest version of a
+				// component
+				final ComponentType oldComponent = components.put(component.getName(), component);
+
+				if (oldComponent.getVersion() > component.getVersion()) {
+					components.put(oldComponent.getName(), oldComponent);
+				}
+			} else {
+				CLASS_LOGGER.warning("Found a duplicate component.\n"
+						+ "Multiple versions of the same component are not currently supported.\n"
+						+ "Only the latest version of the component" + component
+						+ " will be registered .");
+			}
+		} catch (final Exception ex) {
+			CLASS_LOGGER.log(Level.WARNING, ex, () -> "Error found reading component from file "
+					+ pth.toString() + ". This component will not be loaded");
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+		builder.append("FileComponentRepository [");
+
+		if (components != null) {
+			builder.append("components=");
+			builder.append(components);
+			builder.append(", ");
+		}
+
+		if (sourceDirectory != null) {
+			builder.append("sourceDirectory=");
+			builder.append(sourceDirectory);
+		}
+
+		builder.append("]");
+
+		return builder.toString();
+	}
+}
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