Using The Constraint Class

Constraint class is used by constraint definitions to allow you to veto process submittal with parameters values that violate certain rules defined by the constraint class.

Constraint classes implement Constraint and ConstraintFactory.

Syntax

package com.redwood.scheduler.custom.constraint;

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

import com.redwood.scheduler.api.constraint.ConstraintViolatedException;
import com.redwood.scheduler.api.constraint.LOVCollection;
import com.redwood.scheduler.api.constraint.LOVSupport;
import com.redwood.scheduler.api.model.EntityDefinitionConstraintParameterMapping;
import com.redwood.scheduler.api.model.Job;
import com.redwood.scheduler.api.model.JobParameter;
import com.redwood.scheduler.infrastructure.logging.LoggerFactory;
import com.redwood.scheduler.infrastructure.logging.api.Logger;
import com.redwood.scheduler.spi.constraint.Constraint;
import com.redwood.scheduler.api.constraint.ConstraintContext;
import com.redwood.scheduler.spi.constraint.ConstraintFactory;

import com.redwood.scheduler.spi.constraint.ConstraintFactory;

public class SampleConstraint
  implements Constraint, ConstraintFactory
{
  private static final Logger log = LoggerFactory.getRegisteredLogger(RadioConstraint.class,
                                                                      "(C) Copyright 2011-2022 Redwood Technology B.V., Houten, The Netherlands",
                                                                      "$Id$");

  private static final long serialVersionUID = -2920424304798489040L;
  private Map<String, String> parameterMappingsMap;

  @Override
  public Constraint create()
  {
    return new SampleConstraint();
  }

  @Override
  public void execute(ConstraintContext context)
    throws ConstraintViolatedException
  {
    //Logic to validate the constraint
  }

  @Override
  public LOVCollection getLOV(ConstraintContext context, String parameterName, String query, int startAt, int fetchSize)
  {
    //Logic for LOV constraint
  }

  @Override
  public LOVSupport getLOVSupport(ConstraintContext context, String parameterName)
  {
    //Will this contraint return a list of values (LOV)
    //return LOVSupport.NoGetLOV;
    //return
  }

  @Override
  public void validate()
  {
    // nothing to do
  }

  @Override
  public void freeze()
  {
    // TODO Constraint.freeze is an auto-generated method stub

  }

  public Map<String, String> getParameterMappingsMap()
  {
    //Logic for retrieving the parameter mappings
    //return Collections.unmodifiableMap(parameterMappingsMap);
  }

  @Override
  public void setParameterMappings(Iterator<? extends com.redwood.scheduler.api.model.EntityDefinitionConstraintParameterMapping> newParameterMappings)
  {
    parameterMappingsMap = new LinkedHashMap<>();
    if (newParameterMappings == null)
    {
      return;
    }

    while (newParameterMappings.hasNext())
    {
      EntityDefinitionConstraintParameterMapping appliesToParameter = newParameterMappings.next();
      System.out.println("check parameter " + appliesToParameter.getParameterName() + " value:" + appliesToParameter.getValue());
      parameterMappingsMap.put(appliesToParameter.getParameterName(), appliesToParameter.getValue());
    }
  }

  @Override
  public String getDisplayValue(ConstraintContext newContext, String newParameterName, Object newValue)
  {
    // TODO Constraint.getDisplayValue is an auto-generated method stub
    return null;
  }

  @Override
  public void update(ConstraintContext newContext, String newParameterName, String newChangedParameterName)
  {
    //Update the value
  }

  @Override
  public boolean supportsArray()
  {
    // TODO Constraint.supportsArray is an auto-generated method stub
    return false;
  }
}

See Also

Constraint Definition