Writing DL/I calls to access an IMS database with the IMS Universal JDBC driver

This example demonstrates how to make the cast to the DL/I driver and obtain data. This examples accesses a JDBC connection from a JNDI datasource that was created in a JEE server with the IMS Universal Database Resource Adapter.

import java.sql.Connection;

import javax.naming.InitialContext;
import javax.sql.DataSource;

import com.ibm.ims.dli.PCB;
import com.ibm.ims.dli.PSB;
import com.ibm.ims.dli.Path;
import com.ibm.ims.dli.PathSet;
import com.ibm.ims.dli.SSAList;



public class JDBCToDLI {
	public static void main(String args[]){
		
		Connection conn = null; // This is a JDBC Connection
		// This is the equivalent connection object to the JDBC connection for the IMS Java DL/I API
		PSB psb = null; 		
		try{
			// Lookup the JNDI DataSource that contains the IMS connection information. 
			// The JNDI DataSource would be defined in the JEE 
			// server with the IMS Universal Database Resource Adapters
			InitialContext ic = new InitialContext();
			DataSource ds = (DataSource) ic.lookup("myJNDIName");
			
			// Get a JDBC Connection from the DataSource
			conn = ds.getConnection();
			
			// Cast the JDBC Connection to the IMS ConnectImpl in order to retrieve 
			// a handle to the PSB in the IMS Java DL/I API
			psb = ((com.ibm.ims.jdbc.ConnectionImpl) conn).getPSB();
			

			//Get a PCB using the PSB you just created
			PCB ivp1pcb = psb.getPCB("PHONEAP");
			//Allocate PSB1 to establish a connection to the data
			psb.allocate();
			System.out.println("PSB for IVPDB1 Allocated");
			
			//Do work on PSB1
			SSAList ssaList = ivp1pcb.getSSAList("PhoneBook");	//Create an SSA list to use in a DLI call.
										//This SSA list qualifies the entire 
										//PhoneBook segment. PhoneBook is an
										//alias name for segment A1111111 which
										//is specificed in the database view 
										//(DFSIVPDBView.java).

			//Create a path object for later use
			Path path = null;
			PathSet ps = ivp1pcb.batchRetrieve(ssaList);		//This statement uses the PCB object created
										//above to do a batch retrieval of 
										//all the segment instances of PhoneBook.
										//The data returned will be placed in
										//a PathSet which is a collection of
										//Path's containing the data you requested
			System.out.println("Batch retrieved all segment instances of Phone Book");
			
			System.out.println("FIRSTNAME\tLASTNAME\tEXTENSION\tZIPCODE");
			System.out.println("------------------------------------------------------------------");
			
			/*
			* The following while loop process the PathSet by checking that there is
			* a next element (ps.hasNext), then it prints out the three fields that are defined in the
			* database view (FIRSTNAME, LASTNAME, EXTENSION) for segment PhoneBook. This will continue
			* until  there are no more elements in the PathSet
			*/
			while(ps.hasNext()){
				path = ps.next();
				System.out.println(path.getString("FIRSTNAME").trim()+"\t\t"+
				path.getString("LASTNAME").trim()+"\t\t"+
				path.getString("EXTENSION").trim()+"\t"+
				path.getString("ZIPCODE").trim());
			}
				
		    //INSERT a segment into the PhoneBook
		    path = ssaList.getPathForInsert("PhoneBook");
		    path.setString("LASTNAME", "LAST15");
		    path.setString("FIRSTNAME", "FIRST15");
		    path.setString("EXTENSION", "8-111-1515");
		    path.setString("ZIPCODE", "D15/R15");
		    ivp1pcb.insert(path, ssaList);
		    System.out.println("\nInserted New Phone Book Entry with LASTNAME equal to LAST15");
		    
		    //Batch retrieve all segment instances of the PhoneBook (A1111111) segment
		    ps = ivp1pcb.batchRetrieve(ssaList);
		    System.out.println("\nBatch Retrieved all segment instances of Phone Book and verify LAST15 was inserted");
		    
		    System.out.println("FIRSTNAME\tLASTNAME\tEXTENSION\tZIPCODE");
		    System.out.println("------------------------------------------------------------------");
		    while(ps.hasNext()){
		    	path = ps.next();
		    	System.out.println(path.getString("FIRSTNAME").trim()+"\t\t"+
    			path.getString("LASTNAME").trim()+"\t\t"+
    			path.getString("EXTENSION").trim()+"\t"+
    			path.getString("ZIPCODE").trim());
		    }
		    
		    //UPDATE FIRSTNAME to NEWNAME where LASTNAME equals LAST15
		    ssaList.addInitialQualification(1, "LASTNAME", SSAList.EQUALS, "LAST15");
		    if(ivp1pcb.getUnique(path, ssaList, true)){
		    	path.setString("FIRSTNAME", "NEWNAME");
		    	if(16448==ivp1pcb.replace(path)){
		    		System.out.println("\nUpdated FIRSTNAME for segments with LASTNAME of LAST15");
		    	}
		    }
		    
		    ssaList.removeAllQualificationStatements(1);
		    //Batch retrieve all segment instances of the PhoneBook (A1111111) segment
		    ps = ivp1pcb.batchRetrieve(ssaList);
		    System.out.println("\nBatch Retrieved all segment instances of Phone Book and " +
		    		"\nverify that the FISTNAME was updated for the entry LAST15");
		    
		    System.out.println("FIRSTNAME\tLASTNAME\tEXTENSION\tZIPCODE");
		    System.out.println("------------------------------------------------------------------");
		    while(ps.hasNext()){
		    	path = ps.next();
		    	System.out.println(path.getString("FIRSTNAME").trim()+"\t\t"+
    			path.getString("LASTNAME").trim()+"\t\t"+
    			path.getString("EXTENSION").trim()+"\t"+
    			path.getString("ZIPCODE").trim());
		    }
		    
		    //DELETE all segments where LASTNAME equals LAST15
		    ssaList.addInitialQualification(1, "LASTNAME", SSAList.EQUALS, "LAST15");
		    if(ivp1pcb.batchDelete(ssaList)==1){
		    	System.out.println("\nSegment with LASTNAME equal to LAST15 has been deleted");
		    }
		    
		    ssaList.removeAllQualificationStatements(1);
		    
		    //Batch retrieve all segment instances of the PhoneBook (A1111111) segment
		    ps = ivp1pcb.batchRetrieve(ssaList);
		    System.out.println("\nBatch Retrieved all segment instances of Phone Book and " +
		    		"\nverify that the segment with LASTNAME of LAST15 has been deleted");
		    
		    System.out.println("FIRSTNAME\tLASTNAME\tEXTENSION\tZIPCODE");
		    System.out.println("------------------------------------------------------------------");
		    while(ps.hasNext()){
		    	path = ps.next();
		    	System.out.println(path.getString("FIRSTNAME").trim()+"\t\t"+
    			path.getString("LASTNAME").trim()+"\t\t"+
    			path.getString("EXTENSION").trim()+"\t"+
    			path.getString("ZIPCODE").trim());
		    }
		    
		    //Commit the work
		    psb.commit();
		    System.out.println("\nPSB Committed");
		    //Deallocate the PSB
		    psb.deallocate();
		    System.out.println("PSB deallocated");
		    //Close the socket connection
		    psb.close();
		    System.out.println("Connection Closed");
		    System.out.println("Open Database IVP Completed");
		} catch(Exception e) {
			e.printStackTrace();
			try {
			    psb.deallocate();
			    psb.close();
			}catch(Exception e1){
				e1.printStackTrace();
			}
		}
	}
}