Application Developer's Guide

Setting Complex Parameter Types

This section describes how to set an XML data stream to input to a complex parameter type. It contains the following sections:

Architecture of Complex Parameter Types

Complex parameter types provide a facility to use streaming XML data as an input to Liquid Data. You can define an XML data stream of an arbitrary type, and you can use that XML data as input to a query.

Figure 9-1 shows the overall architecture of sending XML data as an input to a query.

Figure 9-1 Setting XML Data as an input to a stored query

Setting XML Data as an input to a stored query

To evaluate a Complex Parameter Type query from the EJB API, you use the setXMLData method on the QueryParameters object.

The following Java code sets the XML data for the input to a stored query, then executes the stored query.

query = (Query) home.create();
QueryParameters qp = new QueryParameters();
qp.setXMLData("CPTSAMPLE", queryParam);
qr= query.executeStored(queryName, qp);

where CPTSAMPLE is a stored query and queryParam is some XML String value.

Sample Complex Parameter Type Code

This section provides sample Java code, using the QueryParameters.setXMLData method, to input XML data into a complex parameter type. For information on defining complex parameter types to Liquid data, see Using Complex Parameter Types in the Administration Guide. For information on using complex parameter types in the Data View Builder, see Using Complex Parameter Types In Queries in Building Queries and Data Views.

The Data View Builder project for the example shown here is installed in the following directory:

BEA_HOME/weblogic81/samples/liquiddata/buildQuery/db-cpt

The code shown in this sample is installed as the following file:

BEA_HOME/weblogic81/samples/liquiddata/ejbAPI/src/ejbSample/QueryWithCptParamClient.java

The section is divided into the following parts:

Sample Query

Assume the following sample query is saved in the Liquid Data repository as the stored query named crm_cptSample.xq. This query uses a complex parameter type (CPTSAMPLE) which contains promotion plan names, and then combines those promotion plan names with the details from the CRM database (PB-CR).

{--	Generated by Data View Builder 8.1	--}
namespace crm1 = "urn:schemas-bea-com:ld-crmp"
namespace crm = "urn:schemas-bea-com:ld-cptSample"

<crm1:db>
	{
	for $CPTSAMPLE.PROMOTION_2 in ($#CPTSAMPLE of type element
        crm:db)/crm:PROMOTION
	let $PROMOTION_PLAN_3 := 
	 	for $PB_CR.PROMOTION_PLAN_4 in
          document("PB-CR")/db/PROMOTION_PLAN
	 	where ($CPTSAMPLE.PROMOTION_2/crm:PROMOTION_NAME  eq 
          $PB_CR.PROMOTION_PLAN_4/PROMOTION_NAME)
	 	return
	 	<PROMOTION_PLAN>
	 	<PROMOTION_NAME>{ xf:data($PB_CR.PROMOTION_PLAN_4/PROMOTION_NAME) }</PROMOTION_NAME>
	 	<PLAN_NAME>{ xf:data($PB_CR.PROMOTION_PLAN_4/PLAN_NAME)}</PLAN_NAME>
	 	<FROM_DATE>{ cast as
      xs:string(xf:data($PB_CR.PROMOTION_PLAN_4/FROM_DATE)) }</FROM_DATE>
	 	<TO_DATE>{ cast as xs:string(xf:data($PB_CR.PROMOTION_PLAN_4/TO_DATE)) 
            }</TO_DATE>
	 	<PRICE>{ cast as xs:string(xf:data($PB_CR.PROMOTION_PLAN_4/PRICE)) }
   </PRICE>
	 	</PROMOTION_PLAN>
	where xf:not(xf:empty($PROMOTION_PLAN_3))
		return
		<PROMOTION>
		<STATE>{ xf:data($CPTSAMPLE.PROMOTION_2/crm:STATE) }</STATE>
		<PROMOTION_NAME>{ xf:data($CPTSAMPLE.PROMOTION_2/crm:PROMOTION_NAME) }</PROMOTION_NAME>
		{ $PROMOTION_PLAN_3 }
	</PROMOTION>
	}
</crm1:db>

Sample Code

The following code sample shows the setXMLData method used to input data into a query that uses a complex parameter type source. To simplify the sample code, this sample creates a String variable named queryParam to represent the XML data stream; you typically will use the setXMLData method to reference an object which contains XML data.

package ejbSample;

import java.rmi.RemoteException;
import java.util.Properties;

import javax.ejb.CreateException;
import javax.ejb.RemoveException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import com.bea.ldi.server.*;
import com.bea.ldi.server.common.*;

import java.io.*;
import java.rmi.*;

public class QueryWithCptParamClient {
   private String url=null;
   private String JNDI_NAME="bea.ldi.server.QueryHome";
   private String queryName=null;
   private static QueryHome home=null;
   private  Query  query =null;

 //  public static boolean stop=false;

   private String queryParam =  
	"<?xml version=\"1.0\" encoding=\"UTF-8\"?> " +
	"     <db xmlns=\"urn:schemas-bea-com:ld-cptSample\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" 

xsi:schemaLocation=\"urn:schemas-bea-com:ld-cptSample crm-p-cptSample.xsd\">" +
		"<PROMOTION>" +
			"<STATE>CA</STATE>" +
			"<PROMOTION_NAME>BROADBAND UPSELL</PROMOTION_NAME>" +
	" 	</PROMOTION>" +
		"<PROMOTION>" +
			"<STATE>TX</STATE>" +
			"<PROMOTION_NAME>WIRELESS UPSELL</PROMOTION_NAME>" +
		"</PROMOTION>" +
		"<PROMOTION>" +
			"<STATE>WA</STATE>" +
			"<PROMOTION_NAME>NEW PRODUCTS</PROMOTION_NAME>" +
		"</PROMOTION>" +
		"<PROMOTION>" +
			"<STATE>AZ</STATE>" +
			"<PROMOTION_NAME>HOLIDAY PROMOTION</PROMOTION_NAME>" +
		"</PROMOTION>" +
		"<PROMOTION>" +
			"<STATE>NV</STATE>" +
	"     		<PROMOTION_NAME>SALES PROMOTION</PROMOTION_NAME>" +
	"      	</PROMOTION>" +
	"      </db>";

   /* normally you would pass the argument for the parameter. But
    * in this example we are hardcoding the XML data stream 
   */	
   public QueryWithCptParamClient(String url, String queryName){
          this.url= url;
          this.queryName=queryName;
   }
   public static void main(String[] args) throws Exception
   {
          QueryWithCptParamClient qpc = new QueryWithCptParamClient(args[0], args[1]);
          qpc.runQuery();
   }

   public void runQuery() throws Exception{
      QueryResult qr=null;
      try{
           if(home==null)
              home = lookupHome();
         // log("Creating a query client");
          query = (Query) home.create();
          QueryParameters qp = new QueryParameters();
          qp.setXMLData("CPTSAMPLE", queryParam);
          qr= query.executeStored(queryName, qp);
          System.out.println("Query Result: >>>>>>>\n");
          if(!qr.isEmpty())
            qr.printWithFormat(new OutputStreamWriter(System.out), true);
      }catch(Exception e){
          throw e;
      }finally{
          qr.close();
      }
   }


  /**
   * Lookup the EJBs home in the JNDI tree
   */
  private QueryHome lookupHome()
    throws NamingException
  {
    // Lookup the beans home using JNDI
    Context ctx = getInitialContext();

    try {
      return (QueryHome)ctx.lookup(JNDI_NAME);
     } catch (NamingException ne) {
       ne.printStackTrace();
      log("The client was unable to lookup the EJBHome.  Please make sure ");
      log("that you have deployed the ejb with the JNDI name "+JNDI_NAME+" on the WebLogic server at "+url);
      throw ne;
    }
  }

   private Context getInitialContext() throws NamingException {

    try {
      // Get an InitialContext
      Properties h = new Properties();
      h.put(Context.INITIAL_CONTEXT_FACTORY,
        "weblogic.jndi.WLInitialContextFactory");
      h.put(Context.PROVIDER_URL, url);
      return new InitialContext(h);
    } catch (NamingException ne) {
      ne.printStackTrace();
      log("We were unable to get a connection to the WebLogic server at "+url);
      log("Please make sure that the server is running.");
      throw ne;
    }
  }

  private static void log(String s) {
    System.out.println(s);
  }

}

Compiling and Running the Sample Code

Perform the following steps to build and run the crm-cpt complex parameter type example.

Open a command window.

Navigate to the BEA_HOME/weblogic81/samples/domains/liquiddata directory as in the following example:

cd /bea/weblogic81/samples/domains/liquiddata

Run the setLDExamplesEnv.cmd script (setLDExamplesEnv.sh on UNIX systems) to set up the environment for the samples, as follows:

setLDExamplesEnv

Change to the BEA_HOME/weblogic81/samples/liquiddata/ejbAPI/build directory as in the following example:

cd /bea/weblogic81/samples/liquiddata/ejbAPI/build

Run ant to build the samples, as follows:

ant

Change to the BEA_HOME/weblogic81/samples/liquiddata/ejbAPI/obj directory as in the following example:

cd /bea/weblogic81/samples/liquiddata/ejbAPI/obj

Run the following command to add the local directory to your CLASSPATH environment directory:

set classpath=%CLASSPATH%;./

Run the sample with the following command, which specifies the Java class with the URL of WebLogic Server as the first argument and the name of the query to run as the second argument:

java ejbSample.QueryWithCptParamClient t3://localhost:7001 crm_cptSample

Note: Make sure your Liquid Data Samples domain is running or this command will fail.

When you run this sample successfully, results similar to the following appear in your command window:

D:\bea\weblogic81\samples\liquiddata\ejbAPI\obj>java ejbSample.QueryWithCptParamClient t3://localhost:7001 crm_cptSample 
Result: >>>>>>>

<crm1:db xmlns:crm1="urn:schemas-bea-com:ld-crmp">
  <PROMOTION>
    <STATE>CA</STATE>
    <PROMOTION_NAME>BROADBAND UPSELL</PROMOTION_NAME>
    <PROMOTION_PLAN>
      <PROMOTION_NAME>BROADBAND UPSELL</PROMOTION_NAME>
      <PLAN_NAME>High Speed Holidays</PLAN_NAME>
      <FROM_DATE>2001-11-22</FROM_DATE>
      <TO_DATE>2002-12-31</TO_DATE>
      <PRICE>100</PRICE>
    </PROMOTION_PLAN>
  </PROMOTION>
  <PROMOTION>
    <STATE>TX</STATE>
    <PROMOTION_NAME>WIRELESS UPSELL</PROMOTION_NAME>
    <PROMOTION_PLAN>
      <PROMOTION_NAME>WIRELESS UPSELL</PROMOTION_NAME>
      <PLAN_NAME>Family Holiday Connect</PLAN_NAME>
      <FROM_DATE>2001-11-22</FROM_DATE>
      <TO_DATE>2002-12-31</TO_DATE>
      <PRICE>49.99</PRICE>
    </PROMOTION_PLAN>
  </PROMOTION>
  <PROMOTION>
    <STATE>WA</STATE>
    <PROMOTION_NAME>NEW PRODUCTS</PROMOTION_NAME>
    <PROMOTION_PLAN>
      <PROMOTION_NAME>NEW PRODUCTS</PROMOTION_NAME>
      <PLAN_NAME>New Phone for the Holidays</PLAN_NAME>
      <FROM_DATE>2001-11-22</FROM_DATE>
      <TO_DATE>2002-12-31</TO_DATE>
      <PRICE>149.99</PRICE>
    </PROMOTION_PLAN>
  </PROMOTION>
  <PROMOTION>
    <STATE>AZ</STATE>
    <PROMOTION_NAME>HOLIDAY PROMOTION</PROMOTION_NAME>
    <PROMOTION_PLAN>
      <PROMOTION_NAME>HOLIDAY PROMOTION</PROMOTION_NAME>
      <PLAN_NAME>New Year New Connections</PLAN_NAME>
      <FROM_DATE>2001-11-22</FROM_DATE>
      <TO_DATE>2002-12-31</TO_DATE>
      <PRICE>39.99</PRICE>
    </PROMOTION_PLAN>
  </PROMOTION>
  <PROMOTION>
    <STATE>NV</STATE>
    <PROMOTION_NAME>SALES PROMOTION</PROMOTION_NAME>
    <PROMOTION_PLAN>
      <PROMOTION_NAME>SALES PROMOTION</PROMOTION_NAME>
      <PLAN_NAME>Family Plan</PLAN_NAME>
      <FROM_DATE>2001-11-22</FROM_DATE>
      <TO_DATE>2002-12-31</TO_DATE>
      <PRICE>39.99</PRICE>
    </PROMOTION_PLAN>
  </PROMOTION>
</crm1:db>