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.mapping; import java.lang.annotation.Annotation; import java.lang.reflect.Constructor; import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Locale; import java.util.Set; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.builder.BuilderException; import org.apache.ibatis.logging.Log; import org.apache.ibatis.logging.LogFactory; import org.apache.ibatis.reflection.ParamNameUtil; import org.apache.ibatis.session.Configuration; /** * @author Clinton Begin */ public class ResultMap { private Configuration configuration; private String id; private Class<?> type; private List<ResultMapping> resultMappings; private List<ResultMapping> idResultMappings; private List<ResultMapping> constructorResultMappings; private List<ResultMapping> propertyResultMappings; private Set<String> mappedColumns; private Set<String> mappedProperties; private Discriminator discriminator; private boolean hasNestedResultMaps; private boolean hasNestedQueries; private Boolean autoMapping; private ResultMap() { } public static class Builder { private static final Log log = LogFactory.getLog(Builder.class); private ResultMap resultMap = new ResultMap(); public Builder(Configuration configuration, String id, Class<?> type, List<ResultMapping> resultMappings) { this(configuration, id, type, resultMappings, null); } public Builder(Configuration configuration, String id, Class<?> type, List<ResultMapping> resultMappings, Boolean autoMapping) { resultMap.configuration = configuration; resultMap.id = id; resultMap.type = type; resultMap.resultMappings = resultMappings; resultMap.autoMapping = autoMapping; } public Builder discriminator(Discriminator discriminator) { resultMap.discriminator = discriminator; return this; } public Class<?> type() { return resultMap.type; } public ResultMap build() { if (resultMap.id == null) { throw new IllegalArgumentException("ResultMaps must have an id"); } resultMap.mappedColumns = new HashSet<>(); resultMap.mappedProperties = new HashSet<>(); resultMap.idResultMappings = new ArrayList<>(); resultMap.constructorResultMappings = new ArrayList<>(); resultMap.propertyResultMappings = new ArrayList<>(); final List<String> constructorArgNames = new ArrayList<>(); for (ResultMapping resultMapping : resultMap.resultMappings) { resultMap.hasNestedQueries = resultMap.hasNestedQueries || resultMapping.getNestedQueryId() != null; resultMap.hasNestedResultMaps = resultMap.hasNestedResultMaps || (resultMapping.getNestedResultMapId() != null && resultMapping.getResultSet() == null); final String column = resultMapping.getColumn(); if (column != null) { resultMap.mappedColumns.add(column.toUpperCase(Locale.ENGLISH)); } else if (resultMapping.isCompositeResult()) { for (ResultMapping compositeResultMapping : resultMapping.getComposites()) { final String compositeColumn = compositeResultMapping.getColumn(); if (compositeColumn != null) { resultMap.mappedColumns.add(compositeColumn.toUpperCase(Locale.ENGLISH)); } } } final String property = resultMapping.getProperty(); if (property != null) { resultMap.mappedProperties.add(property); } if (resultMapping.getFlags().contains(ResultFlag.CONSTRUCTOR)) { resultMap.constructorResultMappings.add(resultMapping); if (resultMapping.getProperty() != null) { constructorArgNames.add(resultMapping.getProperty()); } } else { resultMap.propertyResultMappings.add(resultMapping); } if (resultMapping.getFlags().contains(ResultFlag.ID)) { resultMap.idResultMappings.add(resultMapping); } } if (resultMap.idResultMappings.isEmpty()) { resultMap.idResultMappings.addAll(resultMap.resultMappings); } if (!constructorArgNames.isEmpty()) { final List<String> actualArgNames = argNamesOfMatchingConstructor(constructorArgNames); if (actualArgNames == null) { throw new BuilderException("Error in result map '" + resultMap.id + "'. Failed to find a constructor in '" + resultMap.getType().getName() + "' by arg names " + constructorArgNames + ". There might be more info in debug log."); } resultMap.constructorResultMappings.sort((o1, o2) -> { int paramIdx1 = actualArgNames.indexOf(o1.getProperty()); int paramIdx2 = actualArgNames.indexOf(o2.getProperty()); return paramIdx1 - paramIdx2; }); } // lock down collections resultMap.resultMappings = Collections.unmodifiableList(resultMap.resultMappings); resultMap.idResultMappings = Collections.unmodifiableList(resultMap.idResultMappings); resultMap.constructorResultMappings = Collections.unmodifiableList(resultMap.constructorResultMappings); resultMap.propertyResultMappings = Collections.unmodifiableList(resultMap.propertyResultMappings); resultMap.mappedColumns = Collections.unmodifiableSet(resultMap.mappedColumns); return resultMap; } private List<String> argNamesOfMatchingConstructor(List<String> constructorArgNames) { Constructor<?>[] constructors = resultMap.type.getDeclaredConstructors(); for (Constructor<?> constructor : constructors) { Class<?>[] paramTypes = constructor.getParameterTypes(); if (constructorArgNames.size() == paramTypes.length) { List<String> paramNames = getArgNames(constructor); if (constructorArgNames.containsAll(paramNames) && argTypesMatch(constructorArgNames, paramTypes, paramNames)) { return paramNames; } } } return null; } private boolean argTypesMatch(final List<String> constructorArgNames, Class<?>[] paramTypes, List<String> paramNames) { for (int i = 0; i < constructorArgNames.size(); i++) { Class<?> actualType = paramTypes[paramNames.indexOf(constructorArgNames.get(i))]; Class<?> specifiedType = resultMap.constructorResultMappings.get(i).getJavaType(); if (!actualType.equals(specifiedType)) { if (log.isDebugEnabled()) { log.debug("While building result map '" + resultMap.id + "', found a constructor with arg names " + constructorArgNames + ", but the type of '" + constructorArgNames.get(i) + "' did not match. Specified: [" + specifiedType.getName() + "] Declared: [" + actualType.getName() + "]"); } return false; } } return true; } private List<String> getArgNames(Constructor<?> constructor) { List<String> paramNames = new ArrayList<>(); List<String> actualParamNames = null; final Annotation[][] paramAnnotations = constructor.getParameterAnnotations(); int paramCount = paramAnnotations.length; for (int paramIndex = 0; paramIndex < paramCount; paramIndex++) { String name = null; for (Annotation annotation : paramAnnotations[paramIndex]) { if (annotation instanceof Param) { name = ((Param) annotation).value(); break; } } if (name == null && resultMap.configuration.isUseActualParamName()) { if (actualParamNames == null) { actualParamNames = ParamNameUtil.getParamNames(constructor); } if (actualParamNames.size() > paramIndex) { name = actualParamNames.get(paramIndex); } } paramNames.add(name != null ? name : "arg" + paramIndex); } return paramNames; } } public String getId() { return id; } public boolean hasNestedResultMaps() { return hasNestedResultMaps; } public boolean hasNestedQueries() { return hasNestedQueries; } public Class<?> getType() { return type; } public List<ResultMapping> getResultMappings() { return resultMappings; } public List<ResultMapping> getConstructorResultMappings() { return constructorResultMappings; } public List<ResultMapping> getPropertyResultMappings() { return propertyResultMappings; } public List<ResultMapping> getIdResultMappings() { return idResultMappings; } public Set<String> getMappedColumns() { return mappedColumns; } public Set<String> getMappedProperties() { return mappedProperties; } public Discriminator getDiscriminator() { return discriminator; } public void forceNestedResultMaps() { hasNestedResultMaps = true; } public Boolean getAutoMapping() { return autoMapping; } }