Package org.apache.juddi.query

Source Code of org.apache.juddi.query.FindEntityByCategoryQuery

/*
* Copyright 2001-2008 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

package org.apache.juddi.query;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import javax.persistence.EntityManager;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.juddi.config.Constants;
import org.apache.juddi.query.util.DynamicQuery;
import org.apache.juddi.query.util.FindQualifiers;
import org.apache.juddi.query.util.KeyedRefTModelComparator;
import org.uddi.api_v3.CategoryBag;
import org.uddi.api_v3.KeyedReference;

/**
* Returns the list of "entity" keys possessing the keyedReferences in the passed category bag.
* Output is restricted by list of "entity" keys passed in.  If null, all entities are searched.
* Output is produced by building the appropriate JPA query based on input and find qualifiers.
*
* NOTES:
* 1) Categories are grouped with a logical AND by default.
* 2) Concerning when the categories are AND'd together - the only way this can be done with a single query was to create a self-join for
*    each category.  If there are a lot of categories, the performance could suffer.
*    TODO:  Test performance with multiple AND'd categories.  If too slow, look to process this query in multiple steps.
* 3) The "orLikeKeys" qualifier complicates matters.  The "like" keys are OR'd together and these groups of "like" keys are AND'd together.
*    As with "andAllKeys", self-joins are created but only one for each group of "like" keys.  If none of the keyedReferences passed are alike then this
*    will reduce to an "andAllKeys" query.  If all are alike, then this will query will exhibit the behavior of OR'ing all keys.
*
* @author <a href="mailto:jfaath@apache.org">Jeff Faath</a>
*/
public class FindEntityByCategoryQuery extends EntityQuery {
 
  @SuppressWarnings("unused")
  private static Log log = LogFactory.getLog(FindEntityByCategoryQuery.class);

  private static final String ENTITY_KEYEDREFERENCE = "KeyedReference";
  private static final String ALIAS_KEYEDREFERENCE = buildAlias(ENTITY_KEYEDREFERENCE);
  private static final String FIELD_CATEGORYBAG = "categoryBag";
 
  protected String entityName;
  protected String entityAlias;
  protected String keyName;
  protected String entityField;
  protected String entityNameChild;
  protected String entityAliasChild;
  protected String selectSQL;
  protected String signaturePresent;

  public FindEntityByCategoryQuery(String entityName, String entityAlias, String keyName,
      String entityField, String entityNameChild, String signaturePresent) {
    this.entityName = entityName;
    this.entityAlias = entityAlias;
    this.keyName = keyName;
    this.entityField = entityField;
    this.entityNameChild = entityNameChild;
    this.entityAliasChild = buildAlias(entityNameChild);
    this.signaturePresent = signaturePresent;
   
    StringBuffer sql = new StringBuffer(200);
    sql.append("select distinct " + entityAlias + "." + keyName + " from " + entityName + " " + entityAlias + " , " + entityNameChild + " " + entityAliasChild + " ");
    selectSQL = sql.toString();
  }
 
  public String getEntityName() {
    return entityName;
  }

  public String getEntityAlias() {
    return entityAlias;
  }

  public String getKeyName() {
    return keyName;
  }

  public String getEntityField() {
    return entityField;
  }

  public String getEntityNameChild() {
    return entityNameChild;
  }
 
  public String getEntityAliasChild() {
    return entityAliasChild;
  }
 
  public String getSelectSQL() {
    return selectSQL;
  }
 
  public String getSignaturePresent() {
    return signaturePresent;
  }

  public void setSignaturePresent(String signaturePresent) {
    this.signaturePresent = signaturePresent;
  }
 
  public List<?> select(EntityManager em, FindQualifiers fq, CategoryBag categoryBag, List<?> keysIn, DynamicQuery.Parameter... restrictions) {
    // If keysIn is not null and empty, then search is over.
    if ((keysIn != null) && (keysIn.size() == 0))
      return keysIn;
   
    if (categoryBag == null)
      return keysIn;
   
    List<KeyedReference> categories = categoryBag.getKeyedReference();
    if (categories == null || categories.size() == 0)
      return keysIn;
   
    List<KeyedReference> keyedRefs = new ArrayList<KeyedReference>(0);
    for (KeyedReference elem : categories) {
      if (elem instanceof KeyedReference)
        keyedRefs.add((KeyedReference)elem);
    }
    if (keyedRefs.isEmpty())
      return keysIn;   
   
    DynamicQuery dynamicQry = new DynamicQuery(selectSQL);
    appendConditions(dynamicQry, fq, keyedRefs);
    if (restrictions != null && restrictions.length > 0)
      dynamicQry.AND().pad().appendGroupedAnd(restrictions);

    return getQueryResult(em, dynamicQry, keysIn, entityAlias + "." + keyName);
  }
 
 
  /*
   * Appends the conditions to the query based on the keyedReference list.  With the default or when "orAllKeys" is passed, the keyedReferences are autonomous and are
   * all AND'd or OR'd respectively.  However, "orLikeKeys" requires special treatment.  The goal is to create the conditions in this format:
   *
   * (likeKey1 = X or likeKey1 = Y) and (likeKey2 = A or likeKey2 = B or likeKey2 = C)
   *
   * ie. the "like" KeyedReferences are OR'd and the groups of "like" KeyedReferences are AND'd with each other.
   */
  public void appendConditions(DynamicQuery qry, FindQualifiers fq, List<KeyedReference> keyedRefs) {
   
    // Append the necessary tables (two will always be added connecting the entity to its category table and then the category table to the keyed references).
    appendJoinTables(qry, fq, keyedRefs);
    qry.AND().pad().openParen().pad();
   
    String predicate = DynamicQuery.PREDICATE_EQUALS;
    if (fq.isApproximateMatch()) {
      predicate = DynamicQuery.PREDICATE_LIKE;
    }
   
    // Sorting the collection by tModel Key
    Collections.sort(keyedRefs, new KeyedRefTModelComparator());

    String prevTModelKey = null;
    int count = 0;
    int tblCount = -1;
    for(KeyedReference keyedRef : keyedRefs) {
      String tmodelKey = keyedRef.getTModelKey();
      String keyValue = keyedRef.getKeyValue();
      String keyName = keyedRef.getKeyName();
     
      if (fq.isApproximateMatch()) {
        // JUDDI-235: wildcards are provided by user (only commenting in case a new interpretation arises)
        //keyValue = keyValue.endsWith(DynamicQuery.WILDCARD)?keyValue:keyValue + DynamicQuery.WILDCARD;
        //keyName = keyName.endsWith(DynamicQuery.WILDCARD)?keyName:keyName + DynamicQuery.WILDCARD;
      }

      // Either opening up (and AND'ing) a new "group" of like keys or simply appending an "or".  If this is not "orLikeKeys", then just need to increment
      // the table count.
      if (fq.isOrLikeKeys()) {
        if (count == 0) {
          qry.openParen().pad();
          tblCount++;
        }
        else {
          if (!tmodelKey.equals(prevTModelKey)) {
            qry.closeParen().pad().AND().pad().openParen().pad();
            tblCount++;
          }
          else
            qry.OR().pad();
        }
      }
      else
        tblCount++;
     
      String keyValueTerm = (fq.isOrAllKeys()?ALIAS_KEYEDREFERENCE + "0":ALIAS_KEYEDREFERENCE + tblCount) + ".keyValue";
      String keyNameTerm = (fq.isOrAllKeys()?ALIAS_KEYEDREFERENCE + "0":ALIAS_KEYEDREFERENCE + tblCount) + ".keyName";
      String tmodelKeyTerm = (fq.isOrAllKeys()?ALIAS_KEYEDREFERENCE + "0":ALIAS_KEYEDREFERENCE + tblCount) + ".tmodelKeyRef";
      if (fq.isCaseInsensitiveMatch()) {
        keyValueTerm = "upper(" + keyValueTerm + ")";
        keyValue = keyValue.toUpperCase();
       
        keyNameTerm = "upper(" + keyNameTerm + ")";
        keyName = keyName.toUpperCase();
      }
     
     
      // According to specification, if the "general keyword" tmodel is used, then the keyName must be part of the query.
      if (Constants.GENERAL_KEYWORD_TMODEL.equalsIgnoreCase(tmodelKey)) {
        qry.appendGroupedAnd(new DynamicQuery.Parameter(tmodelKeyTerm, tmodelKey, DynamicQuery.PREDICATE_EQUALS),
                   new DynamicQuery.Parameter(keyValueTerm, keyValue, predicate),
                   new DynamicQuery.Parameter(keyNameTerm, keyName, predicate));
      }
      else {
        qry.appendGroupedAnd(new DynamicQuery.Parameter(tmodelKeyTerm, tmodelKey, DynamicQuery.PREDICATE_EQUALS),
                   new DynamicQuery.Parameter(keyValueTerm, keyValue, predicate));
       
      }
     
      if (count + 1 < keyedRefs.size()) {
        if (fq.isOrAllKeys())
          qry.OR().pad();
        else if (fq.isOrLikeKeys()) {
        }
        else
          qry.AND().pad();
      }
     
      // The "orLikeKeys" will always leave an unclosed parenthesis.  This will close it.
      if (fq.isOrLikeKeys() && (count + 1 == keyedRefs.size()))
        qry.closeParen().pad();

      prevTModelKey = tmodelKey;
      count++;
    }
    qry.closeParen().pad();
   
  }

 
 
  /*
   * Appends the necessary join table for the child entity and additional tables for when keys are AND'd.  When "orLikeKeys" is used,
   * we only need an extra table for each distinct tmodelKey.
   */
  public void appendJoinTables(DynamicQuery qry, FindQualifiers fq, List<KeyedReference> keyedRefs) {
   
    if (keyedRefs != null && keyedRefs.size() > 0) {
      // Sorting the collection by tModel Key
      Collections.sort(keyedRefs, new KeyedRefTModelComparator());

      StringBuffer thetaJoins = new StringBuffer(200);
      int tblCount = 0;
      int count = 0;
      String curTModelKey = null;
      String prevTModelKey = null;
      for(KeyedReference kr : keyedRefs) {
        curTModelKey = kr.getTModelKey();
        if (count != 0) {
          if (!fq.isOrAllKeys()) {
            if (fq.isOrLikeKeys() && curTModelKey.equals(prevTModelKey)) {
              // Do nothing
            }
            else {
              tblCount++;
              qry.comma().pad().append(ENTITY_KEYEDREFERENCE + " " + ALIAS_KEYEDREFERENCE + tblCount).pad();
              thetaJoins.append(ALIAS_KEYEDREFERENCE + (tblCount - 1) + "." + FIELD_CATEGORYBAG + ".id = " + ALIAS_KEYEDREFERENCE + tblCount + "." + FIELD_CATEGORYBAG + ".id ");
              thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
            }
          }

        }
        else {
          qry.comma().pad().append(ENTITY_KEYEDREFERENCE + " " + ALIAS_KEYEDREFERENCE + tblCount).pad();
          thetaJoins.append(entityAliasChild + ".id = " + ALIAS_KEYEDREFERENCE + tblCount + "." + FIELD_CATEGORYBAG + ".id ");
          thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
        }
        prevTModelKey = curTModelKey;
        count++;
      }
     
      qry.WHERE().pad().openParen().pad();
     
      // Appending the middling entity-specific category table condition
      qry.append(entityAlias + "." + keyName + " = " + entityAliasChild + "." + entityField + "." + KEY_NAME).pad();
      qry.AND().pad();

      String thetaJoinsStr = thetaJoins.toString();
      if (thetaJoinsStr.endsWith(DynamicQuery.OPERATOR_AND + " "))
        thetaJoinsStr = thetaJoinsStr.substring(0, thetaJoinsStr.length() - (DynamicQuery.OPERATOR_AND + " ").length());
      qry.append(thetaJoinsStr);

      qry.closeParen().pad();
      if (fq!=null && fq.isSignaturePresent()) {
        qry.AND().pad().openParen().pad().append(getSignaturePresent()).pad().closeParen().pad();
      }
    }
  }
 
}
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