Ans 4 ques 1.
first you have to read the content of file
1. create an object of FileInputStream() : inputFile
2. get the byte stream by calling fuction getBytes(): inputfile.getBytes()
3. the you can directly pass this byte stream in sql query for the blob type of column.
Ans 4 ques 8.
There are many collection interface like set, map, collection, list etc.
set: it will be used when you require unique value only.
map : it will be used for storing (key, value) pairs.
list : it is just to store list of values.