verify file contents in FileOutput test

test/FileOutput.java

@@ -1,7 +1,8 @@
 import java.io.FileOutputStream;
+import java.io.FileInputStream;
+import java.io.File;
 import java.io.IOException;
 
-
 public class FileOutput {
 
   /**
@@ -9,6 +10,7 @@ public class FileOutput {
    * @throws IOException 
    */
   public static void main(String[] args) throws IOException {
+    try {
       FileOutputStream f = new FileOutputStream("test.txt");
       f.write("Hello world!\n".getBytes());
       f.close();
@@ -17,7 +19,22 @@ public class FileOutput {
       f2.write("Hello world again!".getBytes());
       f2.close();
       
+      FileInputStream in = new FileInputStream("test.txt");
+      byte[] buffer = new byte[256];
+      int c;
+      int offset = 0;
+      while ((c = in.read(buffer, offset, buffer.length - offset)) != -1) {
+        offset += c;
+      }
 
+      if (! "Hello world!\nHello world again!".equals
+          (new String(buffer, 0, offset)))
+      {
+        throw new RuntimeException();
+      }
+    } finally {
+      new File("test.txt").delete();
+    }
   }
 
 }