Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.
Hashtable does not allow null keys or values. HashMap allows one null key and any number of null values.
One of HashMap's subclasses is LinkedHashMap, so in the event that you'd want a predictable iteration order (which is insertion order by default), you could easily swap out the HashMap for a LinkedHashMap. This wouldn't be as easy if you were using Hashtable.
String are immutable where as StringBuffer and ...READ MORE
Extends : This is used to get attributes ...READ MORE
JRE: It stands for Java Runtime Environment. ...READ MORE
The equals() method compares the "value" inside String instances ...READ MORE
You can use Java Runtime.exec() to run python script, ...READ MORE
First, find an XPath which will return ...READ MORE
See, both are used to retrieve something ...READ MORE
Nothing to worry about here. In the ...READ MORE
The basic difference is : Map is ...READ MORE
getParameter() returns http request parameters. Those passed from ...READ MORE