Using Eclipse to Develop Java Programs

IEEM241 Routing and Fleet Management

Feb 14, 2005

Outline

• Introduction to Eclipse

• Download & Install Eclipse

• Review HelloWorldApp and FileIO applications with Eclipse

• A simple parsing tool– StringTokenizer

Eclipse

• IDE (Integrated Development Environment) for Java with many powerful features, i.e. – syntax auto-checking– Debug– ……

• Developed by IBM• Free• Official website http://www.eclipse.org/

Download Eclipse

• http://143.89.21.185/ieem241

• http://143.89.20.211/~kick

• ftp://ieem241:ieem241@143.89.21.185

Please download eclipse-SDK-2.1.3-win32.zip

from any of the websites listed above

You may also download ~/t2/InstructionEclipse.pdf and ~/t1/sample.zip

Parse Lines in Files

• readLine( ) is not enough, i.e. need to break the long sentence into individual words.

• Create a StringTokenizer to parse a string str with default delimiter (blank space)

StringTokenizer st = new StringTokenizer(str);

• Create a StringTokenizer with delimiter “,”StringTokenizer st = new StringTokenizer(str, “,”);

Parse Lines in Files

• A common way to use StringTokenizerimport java.util.StringTokenizer;//or import java.util.*;……

StringTokenizer st = new StringTokenizer(str);while(st.hasMoreTokens()){

String token = st.NextToken();……//handle the tokens

}

Data format

• Integer.parseInt(str)– To parse a string str into integer number

• Float.parseFloat(str)– To parse a string str into float number

Example

• A simple counter which counts the total demand in a list which contains a customer name and the demand of the customer

• Data file – demandlist.txt• sample code – Counter.java• http://143.89.21.185/ieem241/t2• http://143.89.20.211/~kick/t2• ftp://ieem241:ieem241@143.89.21.185/t2

In-class Exercise

• Read from a file of arc information, the first line indicates the arc numbers, and other lines each contains three numbers: the from_node, the to_node, and the cost of this arc.

• Find the arc which has the lowest cost.• A brief frame of the program is provided, y

ou can download Arc.java from either of the mirror websites in ~/t2.