UNIX: find and grep best practice

How to run  last executed find command in Unix – Example 1 

javin@testenv1 ~/java : !find
find . -name "*.java"     --last find command executed
./OnlineStockTrading.java
./StockTrading.java

How to find files which have been modified less than one day, minute or hour  in Unix:

javin@testenv1 ~/java : find . -mtime 1  (find all the files modified exact 1 day)

javin@testenv1 ~/java : find . -mtime -1 (find all the files modified less than 1 day)
.
./StockTrading.java

javin@testenv1 ~/java : find . -mtime +1 (find all the files modified more than 1 day)
./.vimrc
./OnlineStockTrading.java
./StockTrading.java~