Java Beginner questions

• How to take text from an HTML element which uses a custom attribute?
• Difference between Hash32 and Hash in Java string Object [duplicate]
• JVM Implementing JRE
• Why retainAll in ArrayList throws an Exception
• Getting previous particular day in a week
• Creating object with reference to Interface
• Assigning ArrayList to List [duplicate]
• DataOutputStream#writeBytes(String) vs BufferedWriter#write(String)
• Populating checkboxes in JSP page with data from a JavaBean
• Adding interceptors in struts.xml for all Action classes

Java Beginner answers