This lesson uses a simple application that we provide to you.
- Create a file named
Count.java
on your local computer by either copying or downloading theCount.java
source code. The examples in this lesson assume that you placecount
in theC:\Test
directory.
- The
count
application needs to access a text file containing the data it will process. Download a sample data file here, or use any other convenient text file as data.
Important: Put your data file into a directory other than the directory containing your downloadedcount
class file. We suggestC:\TestData\data
.
Later in this lesson you will see how an application running under a security manager cannot read a file unless it has explicit permission to do so. However, an application can always read a file from the same directory (or a subdirectory). It does not need explicit permission.
- Compile and then run the
Count
application to see what it does.
When you run thecount
application, you need to specify (as an argument) the path name of a file to be read.
java Count C:\TestData\data
Here is a sample run:
C:\Test>java Count C:\TestData\data Counted 65 chars.