Java tutorial
/* * 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.HashSet; import java.util.List; import java.util.Set; 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.KeyedRefGroupTModelComparator; import org.uddi.api_v3.CategoryBag; import org.uddi.api_v3.KeyedReference; import org.uddi.api_v3.KeyedReferenceGroup; /** * Returns the list of "entity" keys possessing the keyedReferenceGroups 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) Category groups 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 FindEntityByCategoryGroupQuery extends EntityQuery { @SuppressWarnings("unused") private static Log log = LogFactory.getLog(FindEntityByCategoryGroupQuery.class); private static final String ENTITY_KEYEDREFERENCEGROUP = "KeyedReferenceGroup"; private static final String ALIAS_KEYEDREFERENCEGROUP = "krg"; private static final String FIELD_CATEGORYBAG = "categoryBag"; private static final String ENTITY_KEYEDREFERENCE = "KeyedReference"; private static final String ALIAS_KEYEDREFERENCE = buildAlias(ENTITY_KEYEDREFERENCE); private static final String FIELD_KEYEDREFERENCEGROUP = "keyedReferenceGroup"; private String entityName; private String entityAlias; private String keyName; private String entityField; private String entityNameChild; private String entityAliasChild; private String selectSQL; private String signaturePresent; public FindEntityByCategoryGroupQuery(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 + " , " + ENTITY_KEYEDREFERENCEGROUP + " " + ALIAS_KEYEDREFERENCEGROUP + " "); 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; } @SuppressWarnings("unchecked") 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<KeyedReferenceGroup> categories = categoryBag.getKeyedReferenceGroup(); if (categories == null || categories.size() == 0) return keysIn; List<KeyedReferenceGroup> keyedRefGroups = new ArrayList<KeyedReferenceGroup>(0); for (KeyedReferenceGroup elem : categories) { if (elem instanceof KeyedReferenceGroup) keyedRefGroups.add((KeyedReferenceGroup) elem); } if (keyedRefGroups.size() == 0) return keysIn; Collections.sort(keyedRefGroups, new KeyedRefGroupTModelComparator()); int count = 0; String prevTModelKey = null; Set<String> orResults = new HashSet<String>(0); List<?> restrictionList = keysIn; List<?> curResult = null; for (KeyedReferenceGroup keyedRefGroup : keyedRefGroups) { String curTModelKey = keyedRefGroup.getTModelKey(); DynamicQuery dynamicQry = new DynamicQuery(selectSQL); appendConditions(dynamicQry, fq, keyedRefGroup); if (restrictions != null && restrictions.length > 0) dynamicQry.AND().pad().appendGroupedAnd(restrictions); if (fq.isOrLikeKeys()) { if (!curTModelKey.equals(prevTModelKey)) { if (count != 0) { restrictionList = new ArrayList<String>(orResults); orResults.clear(); } } } else if (!fq.isOrAllKeys()) { if (count != 0) restrictionList = curResult; } if (restrictionList != null && restrictionList.size() == 0) break; curResult = getQueryResult(em, dynamicQry, restrictionList, entityAlias + "." + keyName); if (fq.isOrAllKeys() || fq.isOrLikeKeys()) { orResults.addAll((List<String>) curResult); } prevTModelKey = curTModelKey; count++; } List<String> result = null; if (fq.isOrAllKeys() || fq.isOrLikeKeys()) { result = new ArrayList<String>(0); result.addAll(orResults); } else result = (List<String>) curResult; return result; } /* * Appends the conditions to the query based on the keyedReferenceGroup. According to the specification, a keyedReference group matches if all * keyedReferences within the group are a subset of the target entity's group. Thus, */ public void appendConditions(DynamicQuery qry, FindQualifiers fq, KeyedReferenceGroup keyedRefGroup) { // Append the necessary tables (two will always be added connecting the entity to its category bag table and then the category table to the keyed reference group). appendJoinTables(qry, fq, keyedRefGroup); // First, appending the group's tmodel key as a condition qry.AND().pad().appendGroupedAnd(new DynamicQuery.Parameter(ALIAS_KEYEDREFERENCEGROUP + ".tmodelKey", keyedRefGroup.getTModelKey(), DynamicQuery.PREDICATE_EQUALS)); List<KeyedReference> keyedRefs = keyedRefGroup.getKeyedReference(); if (keyedRefs != null && keyedRefs.size() > 0) { qry.AND().pad().openParen().pad(); String predicate = DynamicQuery.PREDICATE_EQUALS; if (fq.isApproximateMatch()) { predicate = DynamicQuery.PREDICATE_LIKE; } 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; } tblCount++; String keyValueTerm = ALIAS_KEYEDREFERENCE + tblCount + ".keyValue"; String keyNameTerm = ALIAS_KEYEDREFERENCE + tblCount + ".keyName"; String tmodelKeyTerm = 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()) qry.AND().pad(); 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, KeyedReferenceGroup keyedRefGroup) { if (keyedRefGroup != null) { List<KeyedReference> keyedRefs = keyedRefGroup.getKeyedReference(); StringBuffer thetaJoins = new StringBuffer(200); if (keyedRefs != null && keyedRefs.size() > 0) { int tblCount = 0; for (int count = 0; count < keyedRefs.size(); count++) { if (count != 0) { tblCount++; qry.comma().pad().append(ENTITY_KEYEDREFERENCE + " " + ALIAS_KEYEDREFERENCE + tblCount) .pad(); thetaJoins.append(ALIAS_KEYEDREFERENCE + (tblCount - 1) + "." + FIELD_KEYEDREFERENCEGROUP + ".id = " + ALIAS_KEYEDREFERENCE + tblCount + "." + FIELD_KEYEDREFERENCEGROUP + ".id "); thetaJoins.append(DynamicQuery.OPERATOR_AND + " "); } else { qry.comma().pad().append(ENTITY_KEYEDREFERENCE + " " + ALIAS_KEYEDREFERENCE + tblCount) .pad(); thetaJoins.append(ALIAS_KEYEDREFERENCEGROUP + ".id = " + ALIAS_KEYEDREFERENCE + tblCount + "." + FIELD_KEYEDREFERENCEGROUP + ".id "); thetaJoins.append(DynamicQuery.OPERATOR_AND + " "); } } } 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(); // Now, appending the condition that attaches the keyed reference group table qry.append(entityAliasChild + ".id = " + ALIAS_KEYEDREFERENCEGROUP + "." + FIELD_CATEGORYBAG + ".id") .pad(); String thetaJoinsStr = thetaJoins.toString(); if (thetaJoinsStr != null && thetaJoinsStr.length() > 0) qry.AND().pad(); 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(); } } } }