add timeout

src/main/java/io/github/novacrypto/SecureCharBuffer.java

@@ -23,6 +23,8 @@
 package io.github.novacrypto;
 
 import java.io.Closeable;
+import java.util.Timer;
+import java.util.TimerTask;
 
 /**
  * A store of char data that is encrypted with a one-time-pad.
@@ -107,6 +109,21 @@ public void close() {
         buffer.close();
     }
 
+    /**
+     * @param delay delay in milliseconds before task is to be executed.
+     */
+    public void timout(int delay) {
+        new Timer().schedule(
+                new TimerTask() {
+                    @Override
+                    public void run() {
+                        buffer.close();
+                    }
+                },
+                delay
+        );
+    }
+
     @Override
     public String toString() {
         throw new UnsupportedOperationException();

src/test/java/io/github/novacrypto/SecureCharBufferTests.java

@@ -150,6 +150,20 @@ public void readAndWriteAllLargeChars() {
         }
     }
 
+    @Test
+    public void testTimeout() throws InterruptedException {
+        SecureCharBuffer buffer = new SecureCharBuffer();
+        buffer.append("abc");
+        buffer.timout(1000);
+        Thread.sleep(1500);
+        final String read = readWholeBufferAsString(buffer);
+        assertEquals(512, buffer.length());
+        assertEquals(512, read.length());
+        for (int i = 0; i < read.length(); i++) {
+            assertEquals('\0', read.charAt(i));
+        }
+    }
+
     private static char readCharAt(SecureCharBuffer buffer, int index) {
         final char c1 = buffer.get(index);
         final char c2 = buffer.charAt(index);