1. 1 Creating Data Access Services Presented by Ashraf Memon Hands-on Ghulam Memon, Longjiang Ding

2. 2 Overview Writing data access service classes in Java Generating service Deploying services with Apache Axis Generating client files and testing them

3. 3 Writing data access service classes in Java Data Access code in Java heavily relies on JDBC (Java Database Connectivity) JDBC is a industry standard Java API from Sun Microsystems for communicating with almost all the database. The driver is usually provided by the database company.

4. 4 Writing data access service classes in Java

5. 5 Sample Data Access class contains 1 function, which reads country data from PGAP database and generates XML for it Method signature is –public String getData(String countryName) Anatomy of class code follows on next slide For complete source code check c:\data\csig05\ws\solutions\database\DBAccess.java

6. 6 Code Anatomy Load JDBC Driver –Class.forName("com.mysql.jdbc.Driver"); Establish databse conenction –Connection connection = DriverManager.getConnection( "jdbc:mysql://geon07.sdsc.edu:3306/test", "csig", "csig"); Create jdbc statement – Statement stmt = connection.createStatement(); Execute SQL query –stmt.executeQuery(sql); Get database metadata (schema) ResultSetMetaData rsmd = records.getMetaData(); int numColumns = rsmd.getColumnCount(); String columnNames[] = new String[numColumns+1]; // Get the column names; column indices start from 1 for (int i=1; i<numColumns+1; i++) { columnNames[i] = rsmd.getColumnName(i); }

7. 7 Code Anatomy (contd) Get result data (schema) while (records.next()) { xml += " \r\n\t\t"; for (int i=1; i<numColumns+1; i++) { xml += " " + records.getString(i) + " \r\n\t\t"; } xml += " \r\n\t"; }

8. 8 Testing the code Navigate to solutions directory c:\data\csig05\ws\solutions Open command prompt by right clicking on the database directory and selecting “Command Prompt Here” Change to database directory by typing following at the command prompt cd database Compile DBAccess.java file by typing following at command prompt javac DBAccess.java Add mySQL JDBC driver to classpath by typing following at the command prompt C:\tools\Tomcat4.1\webapps\axis\WEB-INF\classes\classpath.bat Run program by typing following at command prompt java DBAccess Output should be of the form:

9. 9 Testing the code (contd) GERMANY 53.2 9.6 50000 EUR 703 5 KONINGSMOOR Complete biostratigraphic control null 12-3-92 12465 20010421160313 20010421000549

10. 10 Deploying your code as a web services with Apache Axis Copy generated class file to C:\tools\tomcat4.1\webapps\axis\WEB-INF\classes\ Open using any text editor deployDBAccess.wsdd from C:\tools\tomcat4.1\webapps\axis\WEB-INF\classes\ Verify the content so that it matches the current service and its corresponding class

11. 11 Deploying services with Apache Axis Type following on command line to navigate to C:\tools\tomcat4.1\webapps\axis\WEB- INF\classes\ cd C:\tools\tomcat4.1\webapps\axis\WEB-INF\classes\ Execute deployment descriptor by typing deploy.bat deployDBAccess.wsdd at command prompt This will deploy database webservice on Axis SOAP Server Test it by going to http://localhost/axis/ and navigating to DBAccessServicehttp://localhost/axis/

12. 12 Generating client files and testing them Change directory to c:\data\csig05\ws\solutions\database by typing “cd c:\data\csig05\ws\solutions\database” on the command prompt Compile DBAccessServiceClient.java by typing following at command prompt –javac DBAccess ServiceClient.java Execute Client by typing following at command prompt –java DBAccess ServiceClient Output should be similar to previous one.

13. 13 Creating Web Service to access functionality of a toolCreating Web Service to access functionality of a tool Next Chapter