Java tutorial
/* Copyright (c) 2010, Siemens Corporate Research a Division of Siemens Corporation All rights reserved. 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 com.siemens.scr.avt.ad.query.common; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import java.util.StringTokenizer; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import com.siemens.scr.avt.ad.query.QueryBuilder; import com.siemens.scr.avt.ad.query.model.MappingEntry; /** * Build conjunctive queries without self-joins. An assumption employed is we * are performing natural joins. * * @author Xiang Li * */ public abstract class AbstractQueryBuilder implements QueryBuilder { public static final String AND = "AND"; public static final String FROM = "FROM"; private static Logger logger = Logger.getLogger(AbstractQueryBuilder.class); public static final String NEWLINE = "\r\n"; public static final String SELECT = "SELECT"; public static final String SEPARATOR = ","; public static final String SPACE = " "; public static final String WHERE = "WHERE"; private static String conjunctionOf(List<String> conditions) { return StringUtils.join(conditions, SPACE + AND + SPACE); } private ModelManager modelManager; private Map<String, Object> params; private List<PathElement> aimParams = new ArrayList<PathElement>(); private List<String> projectionList = new LinkedList<String>(); private Set<String> tableSet = new HashSet<String>(); protected String buildAtomicSelection(String key, Object value) { com.siemens.scr.avt.ad.query.model.MappingEntry entry = getModelManager().getMappingEntry(key); return entry.buildSelectionCondition(this, value); } /** * The impl. does not allow self join */ protected String buildCartesionProduct() { return FROM + SPACE + StringUtils.join(tableSet, SEPARATOR); } public String buildFullDicomQuery(Map<Integer, Object> intKeyedParams, Map<String, Object> params) { ModelManager manager = getModelManager(); Map<String, Object> allParams = new HashMap<String, Object>(); allParams.putAll(manager.tag2Key(intKeyedParams)); if (params != null) { allParams.putAll(params); } return buildFullDicomQuery(allParams); } public String buildFullDicomQuery(Map<String, Object> params) { // set up this.params = params; projectionList.add("*"); modelManager.expandTableSetToAllTables(tableSet); return buildQueryInternal(); } protected String buildJoin() { return conjunctionOf(getModelManager().buildJoinConditions(tableSet)); } protected String buildProjection() { return SELECT + SPACE + StringUtils.join(projectionList, SEPARATOR); } public String buildQuery(Map<Integer, Object> intKeyedParams, Map<String, Object> aimCriteria, List<String> out) { ModelManager manager = getModelManager(); Map<String, Object> dicomParams = new HashMap<String, Object>(); dicomParams.putAll(manager.tag2Key(intKeyedParams)); if (params != null) { dicomParams.putAll(params); } List<PathElement> aimParams = new ArrayList<PathElement>(); if (aimCriteria != null) { StringTokenizer tokenizer; for (String key : aimCriteria.keySet()) { tokenizer = new StringTokenizer(key, "."); aimParams.add(new PathElement(tokenizer.nextToken(), tokenizer.nextToken(), aimCriteria.get(key))); } if (aimParams.size() > 0) { tableSet.add("AD.IMAGE_ANNOTATION"); } this.aimParams = aimParams; } return buildQuery(dicomParams, out); } public final String buildQuery(Map<String, Object> params, List<String> out) { preprocess(out, params); return buildQueryInternal(); } private String buildQueryInternal() { String query = buildProjection() + SPACE + NEWLINE + buildCartesionProduct() + SPACE + NEWLINE + buildWhereClause(); return query; } protected String buildSelection() { ArrayList<String> conditions = new ArrayList<String>(); for (String key : params.keySet()) { conditions.add(buildAtomicSelection(key, params.get(key))); } return conjunctionOf(conditions); } protected String buildXMLSelection() { if (aimParams.isEmpty()) { return null; } else { ArrayList<String> conditions = new ArrayList<String>(); for (PathElement element : aimParams) { conditions.add(buildAtomicXMLSelection(element)); } return conjunctionOf(conditions); } } public abstract String buildAtomicXMLSelection(PathElement element); public abstract String buildAtomicSelection(Object value, SimpleEntry entry); public abstract String buildAtomicSelection(Object value, XPathEntry entry); protected String buildWhereClause() { ArrayList<String> components = new ArrayList<String>(); String joinCondition = buildJoin(); if (joinCondition != null && joinCondition.length() > 0) { components.add(joinCondition); } String selection = buildSelection(); if (selection != null && selection.length() > 0) { components.add(selection); } String xmlSelection = buildXMLSelection(); if (xmlSelection != null && xmlSelection.length() > 0) { components.add(xmlSelection); } String condition = conjunctionOf(components); if (condition == null || condition.length() == 0) { return StringUtils.EMPTY; } String whereQueryString = WHERE + SPACE + condition; String wildCardQuery = supportWildcardSearch(whereQueryString); return wildCardQuery; } public ModelManager getModelManager() { return modelManager; } protected void preprocess(List<String> output, Map<String, Object> dicomParams) { this.params = dicomParams; setUpProjectionList(output); setUpTableSet(output); } public void setModelManager(ModelManager modelManager) { this.modelManager = modelManager; } private void setUpProjectionList(List<String> output) { // TODO: extract XML fragments? for (String key : output) { MappingEntry entry = getModelManager().getMappingEntry(key); projectionList.add(entry.toProjectionExpression(this)); } } private void setUpTableSet(List<String> out) { for (String key : params.keySet()) { MappingEntry entry = getModelManager().getMappingEntry(key); if (entry == null) { logger.error("Unknown Search Key:" + key + "!"); } else { tableSet.add(entry.getTableName()); } } for (String key : out) { MappingEntry entry = getModelManager().getMappingEntry(key); if (entry == null) { logger.error("Unknown Search Key:" + key + "!"); } else { tableSet.add(entry.getTableName()); } } modelManager.expandTableSet(tableSet); } private String supportWildcardSearch(String whereQueryString) { if (whereQueryString.contains("*")) { String tmpquery = whereQueryString.replace("='", " like '"); String replaceQuery = tmpquery.replace('*', '%'); return replaceQuery; } else { return whereQueryString; } } }