Java tutorial
/** * Copyright 2009-2019 the original author or authors. * * 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.ibatis.builder; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Properties; import java.util.Set; import java.util.StringTokenizer; import org.apache.ibatis.cache.Cache; import org.apache.ibatis.cache.decorators.LruCache; import org.apache.ibatis.cache.impl.PerpetualCache; import org.apache.ibatis.executor.ErrorContext; import org.apache.ibatis.executor.keygen.KeyGenerator; import org.apache.ibatis.mapping.CacheBuilder; import org.apache.ibatis.mapping.Discriminator; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.ParameterMap; import org.apache.ibatis.mapping.ParameterMapping; import org.apache.ibatis.mapping.ParameterMode; import org.apache.ibatis.mapping.ResultFlag; import org.apache.ibatis.mapping.ResultMap; import org.apache.ibatis.mapping.ResultMapping; import org.apache.ibatis.mapping.ResultSetType; import org.apache.ibatis.mapping.SqlCommandType; import org.apache.ibatis.mapping.SqlSource; import org.apache.ibatis.mapping.StatementType; import org.apache.ibatis.reflection.MetaClass; import org.apache.ibatis.scripting.LanguageDriver; import org.apache.ibatis.session.Configuration; import org.apache.ibatis.type.JdbcType; import org.apache.ibatis.type.TypeHandler; /** * @author Clinton Begin */ public class MapperBuilderAssistant extends BaseBuilder { private String currentNamespace; private final String resource; private Cache currentCache; private boolean unresolvedCacheRef; // issue #676 public MapperBuilderAssistant(Configuration configuration, String resource) { super(configuration); ErrorContext.instance().resource(resource); this.resource = resource; } public String getCurrentNamespace() { return currentNamespace; } public void setCurrentNamespace(String currentNamespace) { if (currentNamespace == null) { throw new BuilderException("The mapper element requires a namespace attribute to be specified."); } if (this.currentNamespace != null && !this.currentNamespace.equals(currentNamespace)) { throw new BuilderException("Wrong namespace. Expected '" + this.currentNamespace + "' but found '" + currentNamespace + "'."); } this.currentNamespace = currentNamespace; } public String applyCurrentNamespace(String base, boolean isReference) { if (base == null) { return null; } if (isReference) { // is it qualified with any namespace yet? if (base.contains(".")) { return base; } } else { // is it qualified with this namespace yet? if (base.startsWith(currentNamespace + ".")) { return base; } if (base.contains(".")) { throw new BuilderException("Dots are not allowed in element names, please remove it from " + base); } } return currentNamespace + "." + base; } public Cache useCacheRef(String namespace) { if (namespace == null) { throw new BuilderException("cache-ref element requires a namespace attribute."); } try { unresolvedCacheRef = true; Cache cache = configuration.getCache(namespace); if (cache == null) { throw new IncompleteElementException("No cache for namespace '" + namespace + "' could be found."); } currentCache = cache; unresolvedCacheRef = false; return cache; } catch (IllegalArgumentException e) { throw new IncompleteElementException("No cache for namespace '" + namespace + "' could be found.", e); } } public Cache useNewCache(Class<? extends Cache> typeClass, Class<? extends Cache> evictionClass, Long flushInterval, Integer size, boolean readWrite, boolean blocking, Properties props) { Cache cache = new CacheBuilder(currentNamespace) .implementation(valueOrDefault(typeClass, PerpetualCache.class)) .addDecorator(valueOrDefault(evictionClass, LruCache.class)).clearInterval(flushInterval).size(size) .readWrite(readWrite).blocking(blocking).properties(props).build(); configuration.addCache(cache); currentCache = cache; return cache; } public ParameterMap addParameterMap(String id, Class<?> parameterClass, List<ParameterMapping> parameterMappings) { id = applyCurrentNamespace(id, false); ParameterMap parameterMap = new ParameterMap.Builder(configuration, id, parameterClass, parameterMappings) .build(); configuration.addParameterMap(parameterMap); return parameterMap; } public ParameterMapping buildParameterMapping(Class<?> parameterType, String property, Class<?> javaType, JdbcType jdbcType, String resultMap, ParameterMode parameterMode, Class<? extends TypeHandler<?>> typeHandler, Integer numericScale) { resultMap = applyCurrentNamespace(resultMap, true); // Class parameterType = parameterMapBuilder.type(); Class<?> javaTypeClass = resolveParameterJavaType(parameterType, property, javaType, jdbcType); TypeHandler<?> typeHandlerInstance = resolveTypeHandler(javaTypeClass, typeHandler); return new ParameterMapping.Builder(configuration, property, javaTypeClass).jdbcType(jdbcType) .resultMapId(resultMap).mode(parameterMode).numericScale(numericScale) .typeHandler(typeHandlerInstance).build(); } public ResultMap addResultMap(String id, Class<?> type, String extend, Discriminator discriminator, List<ResultMapping> resultMappings, Boolean autoMapping) { id = applyCurrentNamespace(id, false); extend = applyCurrentNamespace(extend, true); if (extend != null) { if (!configuration.hasResultMap(extend)) { throw new IncompleteElementException("Could not find a parent resultmap with id '" + extend + "'"); } ResultMap resultMap = configuration.getResultMap(extend); List<ResultMapping> extendedResultMappings = new ArrayList<>(resultMap.getResultMappings()); extendedResultMappings.removeAll(resultMappings); // Remove parent constructor if this resultMap declares a constructor. boolean declaresConstructor = false; for (ResultMapping resultMapping : resultMappings) { if (resultMapping.getFlags().contains(ResultFlag.CONSTRUCTOR)) { declaresConstructor = true; break; } } if (declaresConstructor) { extendedResultMappings .removeIf(resultMapping -> resultMapping.getFlags().contains(ResultFlag.CONSTRUCTOR)); } resultMappings.addAll(extendedResultMappings); } ResultMap resultMap = new ResultMap.Builder(configuration, id, type, resultMappings, autoMapping) .discriminator(discriminator).build(); configuration.addResultMap(resultMap); return resultMap; } public Discriminator buildDiscriminator(Class<?> resultType, String column, Class<?> javaType, JdbcType jdbcType, Class<? extends TypeHandler<?>> typeHandler, Map<String, String> discriminatorMap) { ResultMapping resultMapping = buildResultMapping(resultType, null, column, javaType, jdbcType, null, null, null, null, typeHandler, new ArrayList<>(), null, null, false); Map<String, String> namespaceDiscriminatorMap = new HashMap<>(); for (Map.Entry<String, String> e : discriminatorMap.entrySet()) { String resultMap = e.getValue(); resultMap = applyCurrentNamespace(resultMap, true); namespaceDiscriminatorMap.put(e.getKey(), resultMap); } return new Discriminator.Builder(configuration, resultMapping, namespaceDiscriminatorMap).build(); } public MappedStatement addMappedStatement(String id, SqlSource sqlSource, StatementType statementType, SqlCommandType sqlCommandType, Integer fetchSize, Integer timeout, String parameterMap, Class<?> parameterType, String resultMap, Class<?> resultType, ResultSetType resultSetType, boolean flushCache, boolean useCache, boolean resultOrdered, KeyGenerator keyGenerator, String keyProperty, String keyColumn, String databaseId, LanguageDriver lang, String resultSets) { if (unresolvedCacheRef) { throw new IncompleteElementException("Cache-ref not yet resolved"); } id = applyCurrentNamespace(id, false); boolean isSelect = sqlCommandType == SqlCommandType.SELECT; MappedStatement.Builder statementBuilder = new MappedStatement.Builder(configuration, id, sqlSource, sqlCommandType).resource(resource).fetchSize(fetchSize).timeout(timeout) .statementType(statementType).keyGenerator(keyGenerator).keyProperty(keyProperty) .keyColumn(keyColumn).databaseId(databaseId).lang(lang).resultOrdered(resultOrdered) .resultSets(resultSets).resultMaps(getStatementResultMaps(resultMap, resultType, id)) .resultSetType(resultSetType).flushCacheRequired(valueOrDefault(flushCache, !isSelect)) .useCache(valueOrDefault(useCache, isSelect)).cache(currentCache); ParameterMap statementParameterMap = getStatementParameterMap(parameterMap, parameterType, id); if (statementParameterMap != null) { statementBuilder.parameterMap(statementParameterMap); } MappedStatement statement = statementBuilder.build(); configuration.addMappedStatement(statement); return statement; } private <T> T valueOrDefault(T value, T defaultValue) { return value == null ? defaultValue : value; } private ParameterMap getStatementParameterMap(String parameterMapName, Class<?> parameterTypeClass, String statementId) { parameterMapName = applyCurrentNamespace(parameterMapName, true); ParameterMap parameterMap = null; if (parameterMapName != null) { try { parameterMap = configuration.getParameterMap(parameterMapName); } catch (IllegalArgumentException e) { throw new IncompleteElementException("Could not find parameter map " + parameterMapName, e); } } else if (parameterTypeClass != null) { List<ParameterMapping> parameterMappings = new ArrayList<>(); parameterMap = new ParameterMap.Builder(configuration, statementId + "-Inline", parameterTypeClass, parameterMappings).build(); } return parameterMap; } private List<ResultMap> getStatementResultMaps(String resultMap, Class<?> resultType, String statementId) { resultMap = applyCurrentNamespace(resultMap, true); List<ResultMap> resultMaps = new ArrayList<>(); if (resultMap != null) { String[] resultMapNames = resultMap.split(","); for (String resultMapName : resultMapNames) { try { resultMaps.add(configuration.getResultMap(resultMapName.trim())); } catch (IllegalArgumentException e) { throw new IncompleteElementException("Could not find result map '" + resultMapName + "' referenced from '" + statementId + "'", e); } } } else if (resultType != null) { ResultMap inlineResultMap = new ResultMap.Builder(configuration, statementId + "-Inline", resultType, new ArrayList<>(), null).build(); resultMaps.add(inlineResultMap); } return resultMaps; } public ResultMapping buildResultMapping(Class<?> resultType, String property, String column, Class<?> javaType, JdbcType jdbcType, String nestedSelect, String nestedResultMap, String notNullColumn, String columnPrefix, Class<? extends TypeHandler<?>> typeHandler, List<ResultFlag> flags, String resultSet, String foreignColumn, boolean lazy) { Class<?> javaTypeClass = resolveResultJavaType(resultType, property, javaType); TypeHandler<?> typeHandlerInstance = resolveTypeHandler(javaTypeClass, typeHandler); List<ResultMapping> composites; if ((nestedSelect == null || nestedSelect.isEmpty()) && (foreignColumn == null || foreignColumn.isEmpty())) { composites = Collections.emptyList(); } else { composites = parseCompositeColumnName(column); } return new ResultMapping.Builder(configuration, property, column, javaTypeClass).jdbcType(jdbcType) .nestedQueryId(applyCurrentNamespace(nestedSelect, true)) .nestedResultMapId(applyCurrentNamespace(nestedResultMap, true)).resultSet(resultSet) .typeHandler(typeHandlerInstance).flags(flags == null ? new ArrayList<>() : flags) .composites(composites).notNullColumns(parseMultipleColumnNames(notNullColumn)) .columnPrefix(columnPrefix).foreignColumn(foreignColumn).lazy(lazy).build(); } private Set<String> parseMultipleColumnNames(String columnName) { Set<String> columns = new HashSet<>(); if (columnName != null) { if (columnName.indexOf(',') > -1) { StringTokenizer parser = new StringTokenizer(columnName, "{}, ", false); while (parser.hasMoreTokens()) { String column = parser.nextToken(); columns.add(column); } } else { columns.add(columnName); } } return columns; } private List<ResultMapping> parseCompositeColumnName(String columnName) { List<ResultMapping> composites = new ArrayList<>(); if (columnName != null && (columnName.indexOf('=') > -1 || columnName.indexOf(',') > -1)) { StringTokenizer parser = new StringTokenizer(columnName, "{}=, ", false); while (parser.hasMoreTokens()) { String property = parser.nextToken(); String column = parser.nextToken(); ResultMapping complexResultMapping = new ResultMapping.Builder(configuration, property, column, configuration.getTypeHandlerRegistry().getUnknownTypeHandler()).build(); composites.add(complexResultMapping); } } return composites; } private Class<?> resolveResultJavaType(Class<?> resultType, String property, Class<?> javaType) { if (javaType == null && property != null) { try { MetaClass metaResultType = MetaClass.forClass(resultType, configuration.getReflectorFactory()); javaType = metaResultType.getSetterType(property); } catch (Exception e) { //ignore, following null check statement will deal with the situation } } if (javaType == null) { javaType = Object.class; } return javaType; } private Class<?> resolveParameterJavaType(Class<?> resultType, String property, Class<?> javaType, JdbcType jdbcType) { if (javaType == null) { if (JdbcType.CURSOR.equals(jdbcType)) { javaType = java.sql.ResultSet.class; } else if (Map.class.isAssignableFrom(resultType)) { javaType = Object.class; } else { MetaClass metaResultType = MetaClass.forClass(resultType, configuration.getReflectorFactory()); javaType = metaResultType.getGetterType(property); } } if (javaType == null) { javaType = Object.class; } return javaType; } /** Backward compatibility signature. */ public ResultMapping buildResultMapping(Class<?> resultType, String property, String column, Class<?> javaType, JdbcType jdbcType, String nestedSelect, String nestedResultMap, String notNullColumn, String columnPrefix, Class<? extends TypeHandler<?>> typeHandler, List<ResultFlag> flags) { return buildResultMapping(resultType, property, column, javaType, jdbcType, nestedSelect, nestedResultMap, notNullColumn, columnPrefix, typeHandler, flags, null, null, configuration.isLazyLoadingEnabled()); } /** * @deprecated Use {@link Configuration#getLanguageDriver(Class)} */ @Deprecated public LanguageDriver getLanguageDriver(Class<? extends LanguageDriver> langClass) { return configuration.getLanguageDriver(langClass); } /** Backward compatibility signature. */ public MappedStatement addMappedStatement(String id, SqlSource sqlSource, StatementType statementType, SqlCommandType sqlCommandType, Integer fetchSize, Integer timeout, String parameterMap, Class<?> parameterType, String resultMap, Class<?> resultType, ResultSetType resultSetType, boolean flushCache, boolean useCache, boolean resultOrdered, KeyGenerator keyGenerator, String keyProperty, String keyColumn, String databaseId, LanguageDriver lang) { return addMappedStatement(id, sqlSource, statementType, sqlCommandType, fetchSize, timeout, parameterMap, parameterType, resultMap, resultType, resultSetType, flushCache, useCache, resultOrdered, keyGenerator, keyProperty, keyColumn, databaseId, lang, null); } }