Java 的 MyBatis SQL 映射器框架

/* * Copyright 2009-2023 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 * * https://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.executor.resultset; import java.lang.reflect.Constructor; import java.lang.reflect.Parameter; import java.sql.CallableStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.text.MessageFormat; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Optional; import java.util.Set; import org.apache.ibatis.annotations.AutomapConstructor; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.binding.MapperMethod.ParamMap; import org.apache.ibatis.cache.CacheKey; import org.apache.ibatis.cursor.Cursor; import org.apache.ibatis.cursor.defaults.DefaultCursor; import org.apache.ibatis.executor.ErrorContext; import org.apache.ibatis.executor.Executor; import org.apache.ibatis.executor.ExecutorException; import org.apache.ibatis.executor.loader.ResultLoader; import org.apache.ibatis.executor.loader.ResultLoaderMap; import org.apache.ibatis.executor.parameter.ParameterHandler; import org.apache.ibatis.executor.result.DefaultResultContext; import org.apache.ibatis.executor.result.DefaultResultHandler; import org.apache.ibatis.executor.result.ResultMapException; import org.apache.ibatis.mapping.BoundSql; import org.apache.ibatis.mapping.Discriminator; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.ParameterMapping; import org.apache.ibatis.mapping.ParameterMode; import org.apache.ibatis.mapping.ResultMap; import org.apache.ibatis.mapping.ResultMapping; import org.apache.ibatis.reflection.MetaClass; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.ReflectorFactory; import org.apache.ibatis.reflection.factory.ObjectFactory; import org.apache.ibatis.session.AutoMappingBehavior; import org.apache.ibatis.session.Configuration; import org.apache.ibatis.session.ResultContext; import org.apache.ibatis.session.ResultHandler; import org.apache.ibatis.session.RowBounds; import org.apache.ibatis.type.JdbcType; import org.apache.ibatis.type.TypeHandler; import org.apache.ibatis.type.TypeHandlerRegistry; import org.apache.ibatis.util.MapUtil; /** * @author Clinton Begin * @author Eduardo Macarron * @author Iwao AVE! * @author Kazuki Shimizu */ public class DefaultResultSetHandler implements ResultSetHandler { private static final Object DEFERRED = new Object(); private final Executor executor; private final Configuration configuration; private final MappedStatement mappedStatement; private final RowBounds rowBounds; private final ParameterHandler parameterHandler; private final ResultHandler<?> resultHandler; private final BoundSql boundSql; private final TypeHandlerRegistry typeHandlerRegistry; private final ObjectFactory objectFactory; private final ReflectorFactory reflectorFactory; // nested resultmaps private final Map<CacheKey, Object> nestedResultObjects = new HashMap<>(); private final Map<String, Object> ancestorObjects = new HashMap<>(); private Object previousRowValue; // multiple resultsets private final Map<String, ResultMapping> nextResultMaps = new HashMap<>(); private final Map<CacheKey, List<PendingRelation>> pendingRelations = new HashMap<>(); // Cached Automappings private final Map<String, List<UnMappedColumnAutoMapping>> autoMappingsCache = new HashMap<>(); private final Map<String, List<String>> constructorAutoMappingColumns = new HashMap<>(); // temporary marking flag that indicate using constructor mapping (use field to reduce memory usage) private boolean useConstructorMappings; private static class PendingRelation { public MetaObject metaObject; public ResultMapping propertyMapping; } private static class UnMappedColumnAutoMapping { private final String column; private final String property; private final TypeHandler<?> typeHandler; private final boolean primitive; public UnMappedColumnAutoMapping(String column, String property, TypeHandler<?> typeHandler, boolean primitive) { this.column = column; this.property = property; this.typeHandler = typeHandler; this.primitive = primitive; } } public DefaultResultSetHandler(Executor executor, MappedStatement mappedStatement, ParameterHandler parameterHandler, ResultHandler<?> resultHandler, BoundSql boundSql, RowBounds rowBounds) { this.executor = executor; this.configuration = mappedStatement.getConfiguration(); this.mappedStatement = mappedStatement; this.rowBounds = rowBounds; this.parameterHandler = parameterHandler; this.boundSql = boundSql; this.typeHandlerRegistry = configuration.getTypeHandlerRegistry(); this.objectFactory = configuration.getObjectFactory(); this.reflectorFactory = configuration.getReflectorFactory(); this.resultHandler = resultHandler; } // // HANDLE OUTPUT PARAMETER // @Override public void handleOutputParameters(CallableStatement cs) throws SQLException { final Object parameterObject = parameterHandler.getParameterObject(); final MetaObject metaParam = configuration.newMetaObject(parameterObject); final List<ParameterMapping> parameterMappings = boundSql.getParameterMappings(); for (int i = 0; i < parameterMappings.size(); i++) { final ParameterMapping parameterMapping = parameterMappings.get(i); if (parameterMapping.getMode() == ParameterMode.OUT || parameterMapping.getMode() == ParameterMode.INOUT) { if (ResultSet.class.equals(parameterMapping.getJavaType())) { handleRefCursorOutputParameter((ResultSet) cs.getObject(i + 1), parameterMapping, metaParam); } else { final TypeHandler<?> typeHandler = parameterMapping.getTypeHandler(); metaParam.setValue(parameterMapping.getProperty(), typeHandler.getResult(cs, i + 1)); } } } } private void handleRefCursorOutputParameter(ResultSet rs, ParameterMapping parameterMapping, MetaObject metaParam) throws SQLException { if (rs == null) { return; } try { final String resultMapId = parameterMapping.getResultMapId(); final ResultMap resultMap = configuration.getResultMap(resultMapId); final ResultSetWrapper rsw = new ResultSetWrapper(rs, configuration); if (this.resultHandler == null) { final DefaultResultHandler resultHandler = new DefaultResultHandler(objectFactory); handleRowValues(rsw, resultMap, resultHandler, new RowBounds(), null); metaParam.setValue(parameterMapping.getProperty(), resultHandler.getResultList()); } else { handleRowValues(rsw, resultMap, resultHandler, new RowBounds(), null); } } finally { // issue #228 (close resultsets) closeResultSet(rs); } } // // HANDLE RESULT SETS // @Override public List<Object> handleResultSets(Statement stmt) throws SQLException { ErrorContext.instance().activity("handling results").object(mappedStatement.getId()); final List<Object> multipleResults = new ArrayList<>(); int resultSetCount = 0; ResultSetWrapper rsw = getFirstResultSet(stmt); List<ResultMap> resultMaps = mappedStatement.getResultMaps(); int resultMapCount = resultMaps