diff --git a/tools/coffee-manager/se/sics/coffee/CoffeeFS.java b/tools/coffee-manager/se/sics/coffee/CoffeeFS.java
index 52db04949..8ed6bdb78 100644
--- a/tools/coffee-manager/se/sics/coffee/CoffeeFS.java
+++ b/tools/coffee-manager/se/sics/coffee/CoffeeFS.java
@@ -37,8 +37,8 @@ import java.util.Map;
 import java.util.TreeMap;
 
 public class CoffeeFS {
-	private CoffeeImage image;
-	private CoffeeConfiguration conf;
+	private final CoffeeImage image;
+	private final CoffeeConfiguration conf;
 	private int currentPage;
 	private Map<String, CoffeeFile> files;
 	private static final int INVALID_PAGE = -1;
@@ -129,27 +129,24 @@ public class CoffeeFS {
         }
         
 	public CoffeeFile insertFile(File file) throws IOException {
-		CoffeeFile coffeeFile;
-		try {
-			FileInputStream input = new FileInputStream(file);
-			int allocatePages = pageCount(file.length());
-			int start = findFreeExtent(allocatePages);
+	    CoffeeFile coffeeFile;
+	    FileInputStream input = new FileInputStream(file);
+	    int allocatePages = pageCount(file.length());
+	    int start = findFreeExtent(allocatePages);
 
-			if (start == INVALID_PAGE) {
-				return null;
-			}
-			CoffeeHeader header = new CoffeeHeader(this, start);
-			header.setName(file.getName());
-			header.setReservedSize(allocatePages);
-			header.allocate();
-			coffeeFile = new CoffeeFile(this, header);
-			writeHeader(header);
-			coffeeFile.insertContents(input);
-			input.close();
-			return coffeeFile;
-		} catch (FileNotFoundException e) {
-		}
-		return null;
+	    if (start == INVALID_PAGE) {
+	        input.close();
+	        return null;
+	    }
+	    CoffeeHeader header = new CoffeeHeader(this, start);
+	    header.setName(file.getName());
+	    header.setReservedSize(allocatePages);
+	    header.allocate();
+	    coffeeFile = new CoffeeFile(this, header);
+	    writeHeader(header);
+	    coffeeFile.insertContents(input);
+	    input.close();
+	    return coffeeFile;
 	}
 
 	public void removeFile(String filename)
diff --git a/tools/coffee-manager/se/sics/coffee/CoffeeImageFile.java b/tools/coffee-manager/se/sics/coffee/CoffeeImageFile.java
index 0bb2db789..147cea2b3 100644
--- a/tools/coffee-manager/se/sics/coffee/CoffeeImageFile.java
+++ b/tools/coffee-manager/se/sics/coffee/CoffeeImageFile.java
@@ -32,38 +32,40 @@
 
 package se.sics.coffee;
 
-import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 
 public class CoffeeImageFile implements CoffeeImage {
-	private RandomAccessFile imageFile;
-	private CoffeeConfiguration conf;
+	private final RandomAccessFile imageFile;
+	private final CoffeeConfiguration conf;
 
 	public CoffeeImageFile(String filename, CoffeeConfiguration conf) throws IOException {
 		this.conf = conf;
-		File file = new File(filename);
-		imageFile = new RandomAccessFile(file, "rw");
+		imageFile = new RandomAccessFile(filename, "rw");
 		if (imageFile.length() == 0) {
 			// Allocate a full file system image.
 			imageFile.setLength(conf.fsSize);
 		}
 	}
 
+	@Override
 	public CoffeeConfiguration getConfiguration() {
 		return conf;
 	}
 
+	@Override
 	public void read(byte[] bytes, int size, int offset) throws IOException {
 		imageFile.seek(conf.startOffset + offset);
 		imageFile.read(bytes, 0, size);
 	}
 
+        @Override
 	public void write(byte[] bytes, int size, int offset) throws IOException {
 		imageFile.seek(conf.startOffset + offset);
 		imageFile.write(bytes, 0, size);
 	}
 
+        @Override
 	public void erase(int size, int offset) throws IOException {
 		byte[] bytes = new byte[256];
 		int chunkSize;
diff --git a/tools/coffee-manager/se/sics/coffee/CoffeeManager.java b/tools/coffee-manager/se/sics/coffee/CoffeeManager.java
index fd6d20734..0f409941b 100644
--- a/tools/coffee-manager/se/sics/coffee/CoffeeManager.java
+++ b/tools/coffee-manager/se/sics/coffee/CoffeeManager.java
@@ -40,20 +40,18 @@ import se.sics.coffee.CoffeeFS.CoffeeException;
 import se.sics.coffee.CoffeeFS.CoffeeFileException;
 
 public class CoffeeManager {
-	private static CoffeeFS coffeeFS;
 	public enum Command { INSERT, EXTRACT, REMOVE, LIST, STATS };
 
 	public static void main(String args[]) {
 		String platform = "sky";
-		String usage = "Usage: java -jar coffee.jar ";
 		Command command = Command.STATS;
 		String filename = "";
 		String fsImage = "";
-
-		usage += "[-p <hardware platform>] ";
-		usage += "[-i|e|r <file>] ";
-		usage += "[-l|s] ";
-		usage += "<file system image>";
+		String usage = "Usage: java -jar coffee.jar " +
+		        "[-p <hardware platform>] " +
+		        "[-i|e|r <file>] " +
+		        "[-l|s] " +
+		        "<file system image>";
 
 		if (args.length < 2) {
 			System.err.println(usage);
@@ -98,7 +96,7 @@ public class CoffeeManager {
 
 		try {
 			CoffeeConfiguration conf = new CoffeeConfiguration(platform + ".properties");
-			coffeeFS = new CoffeeFS(new CoffeeImageFile(fsImage, conf));
+			CoffeeFS coffeeFS = new CoffeeFS(new CoffeeImageFile(fsImage, conf));
 			switch (command) {
 			case INSERT:
 				if (coffeeFS.getFiles().get(filename) != null) {