diff --git a/Blatt3/src/tool/DirectoryCompressor.java b/Blatt3/src/tool/DirectoryCompressor.java
new file mode 100644
index 0000000..18250a6
--- /dev/null
+++ b/Blatt3/src/tool/DirectoryCompressor.java
@@ -0,0 +1,20 @@
+package tool;
+
+import java.io.File;
+import java.io.FileFilter;
+
+/**
+ * Compresses the content of a directory.
+ */
+public class DirectoryCompressor extends DirectoryToolBase {
+
+    public static void main(String[] args) throws Exception {
+
+        if (args.length != 1) {
+            System.err.println("Bitte geben Sie ein Verzeichnis an.");
+            System.exit(1);
+        }
+
+        // TODO: Methode implementieren
+    }
+}
\ No newline at end of file
diff --git a/Blatt3/src/tool/DirectoryDecompressor.java b/Blatt3/src/tool/DirectoryDecompressor.java
new file mode 100644
index 0000000..570644f
--- /dev/null
+++ b/Blatt3/src/tool/DirectoryDecompressor.java
@@ -0,0 +1,20 @@
+package tool;
+
+import java.io.File;
+import java.io.FileFilter;
+
+/**
+ * Decompresses the content of a directory.
+ */
+public class DirectoryDecompressor extends DirectoryToolBase {
+
+    public static void main(String[] args) throws Exception {
+
+        if (args.length != 1) {
+            System.err.println("Bitte geben Sie ein Verzeichnis an.");
+            System.exit(1);
+        }
+
+        // TODO: Methode implementieren
+    }
+}
diff --git a/Blatt3/src/tool/DirectoryToolBase.java b/Blatt3/src/tool/DirectoryToolBase.java
new file mode 100644
index 0000000..6e39738
--- /dev/null
+++ b/Blatt3/src/tool/DirectoryToolBase.java
@@ -0,0 +1,11 @@
+package tool;
+
+import java.io.File;
+
+/**
+ * Base class for all directory based tools.
+ */
+public class DirectoryToolBase {
+
+    // TODO: Gemeinsame Methoden für DirectoryCompressor und DirectoryDecompressor
+}
\ No newline at end of file
diff --git a/Blatt3/src/tool/FileCompressor.java b/Blatt3/src/tool/FileCompressor.java
new file mode 100644
index 0000000..a36a2b2
--- /dev/null
+++ b/Blatt3/src/tool/FileCompressor.java
@@ -0,0 +1,19 @@
+package tool;
+
+import compressor.CompressingOutputStream;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Compresses a single file or stdin.
+ */
+public class FileCompressor {
+
+    public static void main(String... args) throws Exception {
+
+        // TODO: Methode implementieren
+    }
+}
\ No newline at end of file
diff --git a/Blatt3/src/tool/FileDecompressor.java b/Blatt3/src/tool/FileDecompressor.java
new file mode 100644
index 0000000..98d6308
--- /dev/null
+++ b/Blatt3/src/tool/FileDecompressor.java
@@ -0,0 +1,19 @@
+package tool;
+
+import compressor.DecompressingInputStream;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Decompresses a single file or stdin.
+ */
+public class FileDecompressor {
+
+    public static void main(String... args) throws Exception {
+
+        // TODO: Methode implementieren
+    }
+}
\ No newline at end of file