On Sun's compiler you should get a warning like:

Test.java:9: warning: [unchecked] unchecked cast
found   : java.lang.Object
required: java.util.List<java.lang.String>
        data = (List<String>)in.readObject();
                                          ^
1 warning

which should give you enough to google with.

The cast cannot be checked a runtime, therefore a warning is given. With
an up to date compiler, you can suppress the warning using
@SuppressWarnings("unchecked").

The problem is unavoidable with readObject, so I suggest writing a small
method to wrap up the nastiness in. Just so long as you know it is there.

import static com.mycompany.myproject.serial.Serial.readObject;
...
        data = readObject(in);
...

package com.mycompany.myproject.serial;

/** blah */
public class Serial {
    /** blah */
    @SuppressWarnings("unchecked")
    public static <T> T readObject(
        java.io.ObjectInputStream in
    ) throws java.io.IOException, java.lang.ClassNotFoundException {
        return (T)in.readObject();
    }
}

Tom Hawtin

see
http://mindprod.com/jgloss/compileerrormessages.html#TYPESAFETYERASED

try

m_loopingData = ArrayList<TLoopingData>() reader.readObject( );