Added Directory and RegularFile facades for convenient file operations.

lis-commons-io/src/main/java/com/link_intersystems/io/IOConsumer.java

@@ -0,0 +1,25 @@
+package com.link_intersystems.io;
+
+import java.io.IOException;
+
+/**
+ * An {@link java.util.function.Consumer} like interface for I/O related stuff.
+ *
+ * @param <T> an I/O type that might raise an {@link IOException}.
+ */
+@FunctionalInterface
+public interface IOConsumer<T> {
+
+    /**
+     * An {@link IOConsumer} that does nothing (<b>no</b> <b>op</b>eration).
+     *
+     * @param <T>
+     * @return
+     */
+    public static <T> IOConsumer<T> noop() {
+        return t -> {
+        };
+    }
+
+    public void accept(T t) throws IOException;
+}

lis-commons-io/src/main/java/com/link_intersystems/io/file/AbstractFile.java

@@ -0,0 +1,54 @@
+package com.link_intersystems.io.file;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Objects;
+
+import static java.util.Objects.requireNonNull;
+
+public abstract class AbstractFile {
+
+    private Path path;
+
+    protected AbstractFile(Path path) {
+        this.path = requireNonNull(path);
+    }
+
+    /**
+     * @return the {@link Path} of this {@link AbstractFile}.
+     */
+    public Path getPath() {
+        return path;
+    }
+
+    /**
+     * Creates this file. This method does nothing, if the file already exists.
+     *
+     * @throws IOException
+     */
+    public abstract void create() throws IOException;
+
+    /**
+     * @return the parent file of this file if any or <code>null</code>.
+     * @throws IOException
+     */
+    public abstract AbstractFile getParent();
+
+    public boolean exists() {
+        return Files.exists(getPath());
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AbstractFile that = (AbstractFile) o;
+        return Objects.equals(getPath(), that.getPath());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(getPath());
+    }
+}

lis-commons-io/src/main/java/com/link_intersystems/io/file/Directory.java

@@ -0,0 +1,117 @@
+package com.link_intersystems.io.file;
+
+import com.link_intersystems.io.IOConsumer;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+public class Directory extends AbstractFile {
+
+    /**
+     * Creates a {@link Directory} based on the given {@link File}.
+     */
+    public Directory(File dir) {
+        this(dir.toPath());
+    }
+
+    /**
+     * Creates a {@link Directory} based on the given dirpath.
+     *
+     * @param dirpath the path of this {@link Directory}.
+     */
+    public Directory(Path dirpath) {
+        super(dirpath);
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * If this directory does not exist, all parent directories that also do not exist
+     * will be created as well.
+     *
+     * @throws IOException
+     */
+    @Override
+    public void create() throws IOException {
+        Files.createDirectories(getPath());
+    }
+
+    @Override
+    public Directory getParent() {
+        Path parent = getPath().getParent();
+
+        if (parent != null) {
+            return new Directory(parent);
+        }
+
+        return null;
+    }
+
+    /**
+     * @param directoryRelativePath
+     * @return the {@link RegularFile} of the given path relative to this directory.
+     * @throws IOException
+     */
+    public RegularFile file(String directoryRelativePath) throws IOException {
+        return file(Paths.get(directoryRelativePath));
+    }
+
+    /**
+     * @param directoryRelativePath
+     * @return the {@link RegularFile} of the given path relative to this directory.
+     * @throws IOException
+     */
+    public RegularFile file(Path directoryRelativePath) throws IOException {
+        return new RegularFile(getPath().resolve(directoryRelativePath));
+    }
+
+    /**
+     * @return all regular files in this directory.
+     * @throws IOException
+     */
+    public List<RegularFile> listFiles() throws IOException {
+        return listFiles(path -> true);
+    }
+
+    /**
+     * @return all regular files in this directory that match the given file filter.
+     * @throws IOException
+     */
+    public List<RegularFile> listFiles(DirectoryStream.Filter<Path> fileFilter) throws IOException {
+        List<RegularFile> files = new ArrayList<>();
+        forEachFiles(files::add, fileFilter);
+        return files;
+    }
+
+    /**
+     * Invokes the given {@link IOConsumer} for each {@link RegularFile} in this directory.
+     *
+     * @throws IOException
+     */
+    public void forEachFiles(IOConsumer<RegularFile> fileConsumer) throws IOException {
+        forEachFiles(fileConsumer, path -> true);
+    }
+
+    /**
+     * Invokes the given {@link IOConsumer} for each {@link RegularFile} in this directory
+     * that match the given file filter.
+     *
+     * @throws IOException
+     */
+    public void forEachFiles(IOConsumer<RegularFile> fileConsumer, DirectoryStream.Filter<Path> fileFilter) throws IOException {
+        DirectoryStream.Filter<Path> filter = path -> Files.isRegularFile(path) && fileFilter.accept(path);
+
+        try (DirectoryStream<Path> directoryStream = Files.newDirectoryStream(getPath(), filter)) {
+            for (Path path : directoryStream) {
+                RegularFile regularFile = new RegularFile(path);
+                fileConsumer.accept(regularFile);
+            }
+        }
+    }
+}

lis-commons-io/src/main/java/com/link_intersystems/io/file/RegularFile.java

@@ -0,0 +1,131 @@
+package com.link_intersystems.io.file;
+
+import com.link_intersystems.io.IOConsumer;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.nio.file.StandardOpenOption.*;
+
+public class RegularFile extends AbstractFile {
+
+
+    /**
+     * Creates a {@link RegularFile} based on the given {@link File}.
+     */
+    public RegularFile(File file) {
+        this(file.toPath());
+    }
+
+    /**
+     * Creates a {@link RegularFile} based on the given filepath.
+     *
+     * @param filepath the path of this {@link RegularFile}.
+     */
+    public RegularFile(Path filepath) {
+        super(filepath);
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * If the file is created it will be empty.
+     * <p>
+     * You do not have to call this method before any
+     * {@link #write(IOConsumer, Charset)} or {@link #append(IOConsumer, Charset)}
+     * invocation, because these methods will also create this file if it does not exist.
+     *
+     * @throws IOException
+     */
+    @Override
+    public void create() throws IOException {
+        append(IOConsumer.noop());
+    }
+
+    @Override
+    public Directory getParent() {
+        Path parent = getPath().getParent();
+
+        if (parent != null) {
+            return new Directory(parent);
+        }
+
+        return null;
+    }
+
+    /**
+     * Writes the content provided by the {@link Appendable} to this {@link RegularFile} using {@link java.nio.charset.StandardCharsets#UTF_8}.
+     *
+     * @see #write(IOConsumer, Charset)
+     */
+    public void write(IOConsumer<Appendable> contentWriter) throws IOException {
+        write(contentWriter, UTF_8);
+    }
+
+    /**
+     * Writes the content provided by the {@link Appendable} to this {@link RegularFile} using the specified {@link Charset}.
+     *
+     * <ul>
+     *     <li>If parent directories do not exist, they will be created.</li>
+     *     <li>If the file does not exist, it will be created.</li>
+     *     <li>If the file already exists, it will be overwritten.</li>
+     *     <li>If the file is an existent directory, an {@link IOException} is raised.</li>
+     * </ul>
+     * <p>
+     *  This method can also be used to create an empty file
+     *
+     *  <pre>
+     *      RegularFile regularFile = ...;
+     *      regularFile.write({@link IOConsumer#noop()});
+     *  </pre>
+     *
+     * @param contentWriter an {@link Appendable} {@link IOConsumer} used to write the content of this file.
+     * @throws IOException if the file is an existent directory or if the content could not be written.
+     */
+    public void write(IOConsumer<Appendable> contentWriter, Charset charset) throws IOException {
+        ensureParentDirs();
+
+        try (PrintWriter pw = new PrintWriter(new OutputStreamWriter(Files.newOutputStream(getPath(), CREATE, TRUNCATE_EXISTING), charset))) {
+            contentWriter.accept(pw);
+        }
+    }
+
+    private void ensureParentDirs() throws IOException {
+        Path filePath = getPath();
+        Path parentPath = filePath.getParent();
+        if (parentPath != null && !Files.exists(parentPath)) {
+            Files.createDirectories(parentPath);
+        }
+    }
+
+    public void append(IOConsumer<Appendable> contentWriter) throws IOException {
+        append(contentWriter, UTF_8);
+    }
+
+    /**
+     * Appends content provided by the {@link Appendable} to this {@link RegularFile} using the specified {@link Charset}.
+     *
+     * <ul>
+     *     <li>If parent directories do not exist, they will be created.</li>
+     *     <li>If the file does not exist, it will be created and the content will be appended.</li>
+     *     <li>If the file already exists, the content will be appended.</li>
+     *     <li>If the file is an existent directory an {@link IOException} is raised.</li>
+     * </ul>
+     *
+     * @param contentWriter an {@link Appendable} {@link IOConsumer} used to append to the content of this file.
+     * @throws IOException if the file is an existent directory or if the content could not be appended.
+     */
+    public void append(IOConsumer<Appendable> contentWriter, Charset charset) throws IOException {
+        ensureParentDirs();
+
+        try (PrintWriter pw = new PrintWriter(new OutputStreamWriter(Files.newOutputStream(getPath(), CREATE, APPEND), charset))) {
+            contentWriter.accept(pw);
+        }
+    }
+}

lis-commons-io/src/test/java/com/link_intersystems/io/file/AbstractFileTest.java

@@ -0,0 +1,61 @@
+package com.link_intersystems.io.file;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class AbstractFileTest {
+
+    private static class TestFile extends AbstractFile {
+
+        protected TestFile(Path path) {
+            super(path);
+        }
+
+        @Override
+        public void create() {
+
+        }
+
+        @Override
+        public AbstractFile getParent() {
+            return null;
+        }
+    }
+
+    private AbstractFile abstractFile;
+
+    @BeforeEach
+    void setUp(@TempDir Path tempDir) {
+        abstractFile = new TestFile(tempDir);
+    }
+
+    @Test
+    void exists() {
+        assertTrue(abstractFile.exists());
+    }
+
+    @Test
+    void testEquals(@TempDir Path unequalPath) {
+        TestFile equal = new TestFile(abstractFile.getPath());
+        TestFile unequal = new TestFile(unequalPath);
+
+        assertEquals(abstractFile, equal);
+        assertEquals(equal, abstractFile);
+        assertNotEquals(equal, unequal);
+        assertNotEquals(equal, null);
+        assertNotEquals(equal, "");
+    }
+
+    @Test
+    void testHashCode() {
+        TestFile actual = new TestFile(abstractFile.getPath());
+
+        assertEquals(abstractFile.hashCode(), actual.hashCode());
+    }
+}