Problem with fetching Map object from ObjectInputStream

Question

Hi, please can you help me with the following...I've never seen this before (with my limited experience of JDK1.5)
ObjectInputStream is = new ObjectInputStream(new FileInputStream(store));
Map<Integer, Report> readObject = (Map<Integer, Report>) is.readObject();This code gives me a warning...
Type safety: The cast from Object to Map<Integer,Report> is actually checking against the erased type Map
How can I get rid of this warning?

Answer 1

     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     ObjectOutputStream oos = new ObjectOutputStream( baos );
     List<String> list = new LinkedList<String>();
     list.add( "one" );
     list.add( "two" );
     oos.writeObject( list );
     oos.flush(); oos.close();
     ObjectInputStream ois = new ObjectInputStream
         ( new ByteArrayInputStream( baos.toByteArray() ) );
     List<String> list2 = (List<String>)ois.readObject();Give me 1 compile time error (Test.java:109: warning: [unchecked] unchecked cast), and no runtime errors.
Removing the <String> from "list" add some more [uncheked], but still runs fine (no runtime warning). Adding a none-String only causes a problem when I try to "get" it. (class cast).
When do you get this warning?