java beginers

1)i have method that is publis static insert(map p), then i want to store employee information in hashmap

after this method public static insert(map p), what code need to write., how can write a programe for it

2)How can we diplay highest key value pair of hashmap? how can wtite a programe for it.

3)i have array that is object[] obj= { new string("hi"), new vector().add(10), new hashmap().setkey()}

display(obj);

display(object[] obj) {}

Now my question is what is the string length and how to retrieve element from vector and if i give key then i will get the value.

4)

from commandline i give a value that is [email protected] then it will only print gmail.com.