[jboss-user] [jBPM] - Integration with Drools

[Shobhit Tyagi]

roxy1987 [http://community.jboss.org/people/roxy1987] created the discussion

"Integration with Drools"

To view the discussion, visit: http://community.jboss.org/message/576585#576585

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Hi, I am trying to invoke the rules with jBPM. My class definition is following :

package com.jboss.dvd.seam;

import org.drools.PackageIntegrationException;
import org.drools.RuleBase;
import org.drools.RuleBaseFactory;
import org.drools.RuleIntegrationException;
import org.drools.WorkingMemory;
import org.drools.compiler.DrlParser;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
import org.drools.lang.descr.PackageDescr;
import org.drools.reteoo.*;
import org.drools.rule.InvalidPatternException;
import org.drools.rule.Package;
import org.jbpm.context.exe.ContextInstance;
import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;
import java.io.*;
import java.util.Iterator;
import java.util.List;

public class FireRulesActionHandler implements ActionHandler {

  private static final long serialVersionUID = 1L;

  public List objectNames;
  public static String ruleFile;

  /**
   * The FireRulesActionHandler gets variables from the Instance, and asserts
   * them into the Rules Engine and invokes the rules.
   */
  public void execute(ExecutionContext executionContext) throws Exception {

    // load up the rulebase
    RuleBase ruleBase = readRule();
    WorkingMemory workingMemory = ruleBase.newWorkingMemory();

    // load the data
    Object object = null;
    System.out.println(objectNames.toString());

    Iterator iter = objectNames.iterator();
    String objectName = "";
    ContextInstance ci = executionContext.getContextInstance();
    while (iter.hasNext()) {
      objectName = (String) iter.next();
      object = ci.getVariable(objectName);
      System.out.println("object name is: " + objectName);
      // assert the object into the rules engine
      workingMemory.assertObject(object);
    }
    // assert the contextInstance so that it may be used to set results
    workingMemory.assertObject(ci);
    workingMemory.fireAllRules();

  }

  /**
   * Please note that this is the "low level" rule assembly API.
   */
  private static RuleBase readRule() throws IOException, DroolsParserException, RuleIntegrationException, PackageIntegrationException, InvalidPatternException {
    // read in the source
    Reader reader = new InputStreamReader(FireRulesActionHandler.class.getResourceAsStream(ruleFile));
    DrlParser parser = new DrlParser();
    PackageDescr packageDescr = parser.parse(reader);

    // pre build the package
    PackageBuilder builder = new PackageBuilder();
    builder.addPackage(packageDescr);
    Package pkg = builder.getPackage();

    // add the package to a rulebase
    RuleBase ruleBase = RuleBaseFactory.newRuleBase();
    ruleBase.addPackage(pkg);
    return ruleBase;

  }
}

1. First thing is that, it is not able to recognize the function newWorkingMemory().
2. Secondly the function assertObject(Object) is also reported undefined.

Please Help.
Thanks
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