Irretrievably destroying data in Java

Question

Is there anyway in Java to delete data (e.g., a variable value, object) and be sure it can\'t be recovered from memory? Does assigning null to a variable in Jav

Answer 1

By setting your Object to null doesn't mean that your object is removed from memory. The Virtual Machine will flag that Object as ready for Garbage Collection if there are no more references to that Object. Depending on your code it might still be referenced even though you have set it to null in which case it will not be removed. (Essentially if you expect it to be garbage collected and it is not you have a memory leak!)

Once it is flagged as ready for collection you have no control over when the Garbage Collector will remove it. You can mess around with Garbage Collection strategies but I wouldn't advise it. Profile your application and look at the object and it's id and you can see what is referencing it. Java provide VisualVM with 1.6.0_07 and above or you can use NetBeans