Creating File Access Services

Creating File Access Services

Presented by

Ashraf Memon

Presented by

Ashraf Memon

2

Overview

• Writing file access service classes in Java

• Generating service

• Deploying services with Apache Axis

• Generating client files and testing them

3

Writing file access service classes in Java

• A spatial ASCII file will be used as an example for this service.

• ASCII file format is not standard.

• Sample ASCII file looks likeLongitude Latitude Magnitude

143.002 37.2850 2.25000E-02

-106.081 -4.33800 2.50000E-02

151.750 45.3590 3.75000E-02

139.720 -3.22000 2.87500E-02

4

Writing file access service classes in Java (contd)

• First line of the file contains labels i.e. coordinates and attributes

• Each following line contains values

• Each value is seaparated by space

• Each record is separated by a new line.

5

Writing file access service classes in Java (contd)

• Sample File Access Class contains 1 function which reads lat/lon values and attributes from quakes1.dat file and return XML for those values

• Function signature ispublic String parse(String content, int criteria)

• Complete class code follows on next slide.

6

Writing file access service classes in Java (contd)

import java.io.BufferedReader;

import java.io.IOException;

import java.util.StringTokenizer;

import java.io.StringReader;

import java.io.RandomAccessFile;

import java.io.File;

public class AsciiAccess {

public AsciiAccess() {

}

7

Writing file access service classes in Java (contd)

public String parse(String ascii, int magnitudeCriteria) throws IOException{

String xml = "<table>\r\n\t";

BufferedReader reader = new BufferedReader(new StringReader(ascii));

String line = reader.readLine();

line = reader.readLine();

while(line!=null){

StringTokenizer tokenizer = new StringTokenizer(line, " ");

8

Writing file access service classes in Java (contd)

String[] tempArr = new String[tokenizer.countTokens()];

for(int i=0;tokenizer.hasMoreTokens();i++){

tempArr[i]=tokenizer.nextToken();

}

if(Double.parseDouble(tempArr[tempArr.length-1])>magnitudeCriteria){

xml+="<record>\r\n\t\t";

xml+="<lon>"+tempArr[0]+"</lon>\r\n\t\t";

xml+="<lat>"+tempArr[1]+"</lat>\r\n\t\t";

9

Writing file access service classes in Java (contd)

xml+="<magnitude>"+tempArr[2]+"</magnitude>\r\n\t";

xml+="</record>\r\n\t";

}

line = reader.readLine();

}

xml+="\r\n";

xml+="</table>";

return xml;

}

10

Generating Service

• Download AsciiAccessService directory from ftp://dotnet.sdsc.edu/CSIG-WS/

• Save directory to C:\training\user\code

• Copy quakes1.dat to C:\training\user\

• Compile AsciiAccess.java file by typing following at command prompt

javac AsciiAccess.java

11

Generating Service (contd)• Run program by typing following at command prompt

java AsciiAccess

• Output should be<table>

<record>

<lon>143.002</lon>

<lat>37.2850</lat>

<magnitude>2.25000E-02</magnitude>

</record>

</table>

12

Deploying services with Apache Axis

• Copy generated class file to C:\training\tools\tomcat\webapps\axis\WEB-INF\classes\

• Open deployAsciiAccess.wsdd in Textpad (Explanation by instructor)

• Close file.

13

Deploying services with Apache Axis(contd)

• Set classpath by typing classpath at command prompt

• Execute deployment descriptor by typing deploy deployAsciiAccess.wsdd at command prompt.

• This deploys webservice on Axis SOAP Server.

14

Generating client files and testing them(contd)

• Compile AsciiAccessServiceClient.java by typing following at command prompt– javac AsciiAccessServiceClient.java

• Execute Client by typing following at command prompt– java AsciiAccessServiceClient

• Output should be similar to the result of executing AsciiAccess