Java程序辅导

Slawomir Goryczka (sgorycz@emory.edu) 1
Working From Home
The department invests a lot of resources into keeping the computer lab open most of the week. 
There you can find help from a lab representative with computer use issues like copying files, using 
the right compiler, and running applications. Still, since almost everyone has their own computer, 
this page describes how you can get some of your homework done at home.
Downloads
Although most computers already have Java, you may need to download the development version 
to get access to a compiler. Also, if you would like to use Eclipse a download link is provided. Note 
that Eclipse is not necessary, any text editor can be used to write Java programs.
Download Java Development Kit
Eclipse Classic Download 
Copying files to your account
As all assignments to be turned in require you to place your files in the appropriate folder on your 
account (subdirectory of ~/cs170), you will need to copy files from your home computer to the 
system at school. Furthermore, just because homework seems to work on your home system, does 
not mean it is correct. You MUST test your homework in the lab to make sure it is correct.
Mac OS X
Mac OS X comes with the necessary software to do this. The recommended technique is to use the 
terminal  and  the  scp command.  The  terminal  application  on  Mac  OS X can  be  found  in  the 
Applications/Utilities folder. Here is an example  scp (secure copy) command to copy files from 
your Mac to the school system.
scp  Hw3.java  myusername@lab3a.mathcs.emory.edu:cs170/hw3/
The command assumes your Current Working Directory contains the Hw3.java file. It also requires 
you to  specify your  username (EmoryID)  instead  of  "myusername".  Finally,  I  randomly chose 
machine lab3a for this example. Any lab machine should do (lab1a - lab8g). 
Windows
Emory offers the Web Drive client for Windows to all students at Software Express. This software 
can be used to connect to your account on any lab machine (such as lab4a.mathcs.emory.edu). From 
there you can copy files over to the correct location with drag and drop.
You can also download an SCP client for Windows, which works the same way as  scp on Mac. 
There are many SCP clients, i.e.
– WinSCP : http://winscp.net/eng/download.php (Select the "Installation package" 
corresponding to the latest version.)
– PSCP : http://the.earth.li/~sgtatham/putty/latest/x86/pscp.exe 
Slawomir Goryczka (sgorycz@emory.edu) 2
Remote login to lab machines
Mac OS X
Your MAC OS X comes with all the software that you need. Just open the terminal and type what 
follows:
ssh  myusername@lab3a.mathcs.emory.edu 
Once you press return, you will be prompted for password. You might also be prompted to verify 
the key. If so, type yes and press return. 
Windows
You will need to download an external software (that is free) called putty. You can download it here: 
http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe 
This is a direct link to the executable file. All you need to do is to save this file on your computer 
and run it. Once you start the program just use the following: 
In Host type: lab7a.mathcs.emory.edu
Do not change other default options
Click Open (bottom of window)
If Putty gives a security alert, click Yes (this might happen, but does not have to). Type your user 
name and password when prompted (the same as you use to login in lab). Then you will be logged 
in. 
Compiling and running Java
Mac OS X
Just open the terminal and type javac (compiling) or java (running). Just like in the lab. You will 
find the terminal in the Applications/Utilities folder.
Windows
Open a DOS prompt from Start->All Programs->Accessories->Command Prompt. Then try javac 
(compiling) or java (running). Many of the Unix commands work here as well. Note: "ls" is called 
"dir" here.