mybatis-plus/src/main/java/com/baomidou/mybatisplus/MybatisXMLConfigBuilder.java

/**
 * Copyright (c) 2011-2014, hubin (jobob@qq.com).
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.baomidou.mybatisplus;

import java.io.InputStream;
import java.io.Reader;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;

import javax.sql.DataSource;

import org.apache.ibatis.builder.BaseBuilder;
import org.apache.ibatis.builder.BuilderException;
import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.datasource.DataSourceFactory;
import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.executor.loader.ProxyFactory;
import org.apache.ibatis.io.ResolverUtil;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.io.VFS;
import org.apache.ibatis.logging.Log;
import org.apache.ibatis.mapping.DatabaseIdProvider;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.reflection.DefaultReflectorFactory;
import org.apache.ibatis.reflection.MetaClass;
import org.apache.ibatis.reflection.ReflectorFactory;
import org.apache.ibatis.reflection.factory.ObjectFactory;
import org.apache.ibatis.reflection.wrapper.ObjectWrapperFactory;
import org.apache.ibatis.session.AutoMappingBehavior;
import org.apache.ibatis.session.AutoMappingUnknownColumnBehavior;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.LocalCacheScope;
import org.apache.ibatis.transaction.TransactionFactory;
import org.apache.ibatis.type.JdbcType;

/**
 * <p>
 * Copy from XMLConfigBuilder in Mybatis and replace default Configuration class
 * by MybatisConfiguration class
 * </p>
 *
 * @author hubin
 * @Date 2017-01-04
 */
public class MybatisXMLConfigBuilder extends BaseBuilder {

    private boolean parsed;
    private XPathParser parser;
    private String environment;
    private ReflectorFactory localReflectorFactory = new DefaultReflectorFactory();

    public MybatisXMLConfigBuilder(Reader reader) {
        this(reader, null, null);
    }

    public MybatisXMLConfigBuilder(Reader reader, String environment) {
        this(reader, environment, null);
    }

    public MybatisXMLConfigBuilder(Reader reader, String environment, Properties props) {
        this(new XPathParser(reader, true, props, new XMLMapperEntityResolver()), environment, props);
    }

    public MybatisXMLConfigBuilder(InputStream inputStream) {
        this(inputStream, null, null);
    }

    public MybatisXMLConfigBuilder(InputStream inputStream, String environment) {
        this(inputStream, environment, null);
    }

    public MybatisXMLConfigBuilder(InputStream inputStream, String environment, Properties props) {
        this(new XPathParser(inputStream, true, props, new XMLMapperEntityResolver()), environment, props);
    }

    private MybatisXMLConfigBuilder(XPathParser parser, String environment, Properties props) {
        //TODO 自定义 Configuration
        super(new MybatisConfiguration());
        ErrorContext.instance().resource("SQL Mapper Configuration");
        this.configuration.setVariables(props);
        this.parsed = false;
        this.environment = environment;
        this.parser = parser;
    }

    public Configuration parse() {
        if (parsed) {
            throw new BuilderException("Each XMLConfigBuilder can only be used once.");
        }
        parsed = true;
        parseConfiguration(parser.evalNode("/configuration"));
        return configuration;
    }

    private void parseConfiguration(XNode root) {
        try {
            //issue #117 read properties first
            propertiesElement(root.evalNode("properties"));
            Properties settings = settingsAsProperties(root.evalNode("settings"));
            loadCustomVfs(settings);
            typeAliasesElement(root.evalNode("typeAliases"));
            pluginElement(root.evalNode("plugins"));
            objectFactoryElement(root.evalNode("objectFactory"));
            objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
            reflectorFactoryElement(root.evalNode("reflectorFactory"));
            settingsElement(settings);
            // read it after objectFactory and objectWrapperFactory issue #631
            environmentsElement(root.evalNode("environments"));
            databaseIdProviderElement(root.evalNode("databaseIdProvider"));
            typeHandlerElement(root.evalNode("typeHandlers"));
            mapperElement(root.evalNode("mappers"));
        } catch (Exception e) {
            throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
        }
    }

    private Properties settingsAsProperties(XNode context) {
        if (context == null) {
            return new Properties();
        }
        Properties props = context.getChildrenAsProperties();
        // Check that all settings are known to the configuration class
        MetaClass metaConfig = MetaClass.forClass(Configuration.class, localReflectorFactory);
        for (Object key : props.keySet()) {
            if (!metaConfig.hasSetter(String.valueOf(key))) {
                throw new BuilderException("The setting " + key + " is not known.  Make sure you spelled it correctly (case sensitive).");
            }
        }
        return props;
    }

    private void loadCustomVfs(Properties props) throws ClassNotFoundException {
        String value = props.getProperty("vfsImpl");
        if (value != null) {
            String[] clazzes = value.split(",");
            for (String clazz : clazzes) {
                if (!clazz.isEmpty()) {
                    @SuppressWarnings("unchecked")
                    Class<? extends VFS> vfsImpl = (Class<? extends VFS>) Resources.classForName(clazz);
                    configuration.setVfsImpl(vfsImpl);
                }
            }
        }
    }

    private void typeAliasesElement(XNode parent) {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                if ("package".equals(child.getName())) {
                    String typeAliasPackage = child.getStringAttribute("name");
                    configuration.getTypeAliasRegistry().registerAliases(typeAliasPackage);
                } else {
                    String alias = child.getStringAttribute("alias");
                    String type = child.getStringAttribute("type");
                    try {
                        Class<?> clazz = Resources.classForName(type);
                        if (alias == null) {
                            typeAliasRegistry.registerAlias(clazz);
                        } else {
                            typeAliasRegistry.registerAlias(alias, clazz);
                        }
                    } catch (ClassNotFoundException e) {
                        throw new BuilderException("Error registering typeAlias for '" + alias + "'. Cause: " + e, e);
                    }
                }
            }
        }
    }

    private void pluginElement(XNode parent) throws Exception {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                String interceptor = child.getStringAttribute("interceptor");
                Properties properties = child.getChildrenAsProperties();
                Interceptor interceptorInstance = (Interceptor) resolveClass(interceptor).newInstance();
                interceptorInstance.setProperties(properties);
                configuration.addInterceptor(interceptorInstance);
            }
        }
    }

    private void objectFactoryElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            Properties properties = context.getChildrenAsProperties();
            ObjectFactory factory = (ObjectFactory) resolveClass(type).newInstance();
            factory.setProperties(properties);
            configuration.setObjectFactory(factory);
        }
    }

    private void objectWrapperFactoryElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            ObjectWrapperFactory factory = (ObjectWrapperFactory) resolveClass(type).newInstance();
            configuration.setObjectWrapperFactory(factory);
        }
    }

    private void reflectorFactoryElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            ReflectorFactory factory = (ReflectorFactory) resolveClass(type).newInstance();
            configuration.setReflectorFactory(factory);
        }
    }

    private void propertiesElement(XNode context) throws Exception {
        if (context != null) {
            Properties defaults = context.getChildrenAsProperties();
            String resource = context.getStringAttribute("resource");
            String url = context.getStringAttribute("url");
            if (resource != null && url != null) {
                throw new BuilderException("The properties element cannot specify both a URL and a resource based property file reference.  Please specify one or the other.");
            }
            if (resource != null) {
                defaults.putAll(Resources.getResourceAsProperties(resource));
            } else if (url != null) {
                defaults.putAll(Resources.getUrlAsProperties(url));
            }
            Properties vars = configuration.getVariables();
            if (vars != null) {
                defaults.putAll(vars);
            }
            parser.setVariables(defaults);
            configuration.setVariables(defaults);
        }
    }

    private void settingsElement(Properties props) throws Exception {
        configuration.setAutoMappingBehavior(AutoMappingBehavior.valueOf(props.getProperty("autoMappingBehavior", "PARTIAL")));
        configuration.setAutoMappingUnknownColumnBehavior(AutoMappingUnknownColumnBehavior.valueOf(props.getProperty("autoMappingUnknownColumnBehavior", "NONE")));
        configuration.setCacheEnabled(booleanValueOf(props.getProperty("cacheEnabled"), true));
        configuration.setProxyFactory((ProxyFactory) createInstance(props.getProperty("proxyFactory")));
        configuration.setLazyLoadingEnabled(booleanValueOf(props.getProperty("lazyLoadingEnabled"), false));
        configuration.setAggressiveLazyLoading(booleanValueOf(props.getProperty("aggressiveLazyLoading"), false));
        configuration.setMultipleResultSetsEnabled(booleanValueOf(props.getProperty("multipleResultSetsEnabled"), true));
        configuration.setUseColumnLabel(booleanValueOf(props.getProperty("useColumnLabel"), true));
        configuration.setUseGeneratedKeys(booleanValueOf(props.getProperty("useGeneratedKeys"), false));
        configuration.setDefaultExecutorType(ExecutorType.valueOf(props.getProperty("defaultExecutorType", "SIMPLE")));
        configuration.setDefaultStatementTimeout(integerValueOf(props.getProperty("defaultStatementTimeout"), null));
        configuration.setDefaultFetchSize(integerValueOf(props.getProperty("defaultFetchSize"), null));
        configuration.setMapUnderscoreToCamelCase(booleanValueOf(props.getProperty("mapUnderscoreToCamelCase"), false));
        configuration.setSafeRowBoundsEnabled(booleanValueOf(props.getProperty("safeRowBoundsEnabled"), false));
        configuration.setLocalCacheScope(LocalCacheScope.valueOf(props.getProperty("localCacheScope", "SESSION")));
        configuration.setJdbcTypeForNull(JdbcType.valueOf(props.getProperty("jdbcTypeForNull", "OTHER")));
        configuration.setLazyLoadTriggerMethods(stringSetValueOf(props.getProperty("lazyLoadTriggerMethods"), "equals,clone,hashCode,toString"));
        configuration.setSafeResultHandlerEnabled(booleanValueOf(props.getProperty("safeResultHandlerEnabled"), true));
        configuration.setDefaultScriptingLanguage(resolveClass(props.getProperty("defaultScriptingLanguage")));
        configuration.setCallSettersOnNulls(booleanValueOf(props.getProperty("callSettersOnNulls"), false));
        configuration.setUseActualParamName(booleanValueOf(props.getProperty("useActualParamName"), true));
        configuration.setReturnInstanceForEmptyRow(booleanValueOf(props.getProperty("returnInstanceForEmptyRow"), false));
        configuration.setLogPrefix(props.getProperty("logPrefix"));
        @SuppressWarnings("unchecked")
        Class<? extends Log> logImpl = (Class<? extends Log>) resolveClass(props.getProperty("logImpl"));
        configuration.setLogImpl(logImpl);
        configuration.setConfigurationFactory(resolveClass(props.getProperty("configurationFactory")));
    }

    private void environmentsElement(XNode context) throws Exception {
        if (context != null) {
            if (environment == null) {
                environment = context.getStringAttribute("default");
            }
            for (XNode child : context.getChildren()) {
                String id = child.getStringAttribute("id");
                if (isSpecifiedEnvironment(id)) {
                    TransactionFactory txFactory = transactionManagerElement(child.evalNode("transactionManager"));
                    DataSourceFactory dsFactory = dataSourceElement(child.evalNode("dataSource"));
                    DataSource dataSource = dsFactory.getDataSource();
                    Environment.Builder environmentBuilder = new Environment.Builder(id)
                            .transactionFactory(txFactory)
                            .dataSource(dataSource);
                    configuration.setEnvironment(environmentBuilder.build());
                }
            }
        }
    }

    private void databaseIdProviderElement(XNode context) throws Exception {
        DatabaseIdProvider databaseIdProvider = null;
        if (context != null) {
            String type = context.getStringAttribute("type");
            // awful patch to keep backward compatibility
            if ("VENDOR".equals(type)) {
                type = "DB_VENDOR";
            }
            Properties properties = context.getChildrenAsProperties();
            databaseIdProvider = (DatabaseIdProvider) resolveClass(type).newInstance();
            databaseIdProvider.setProperties(properties);
        }
        Environment environment = configuration.getEnvironment();
        if (environment != null && databaseIdProvider != null) {
            String databaseId = databaseIdProvider.getDatabaseId(environment.getDataSource());
            configuration.setDatabaseId(databaseId);
        }
    }

    private TransactionFactory transactionManagerElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            Properties props = context.getChildrenAsProperties();
            TransactionFactory factory = (TransactionFactory) resolveClass(type).newInstance();
            factory.setProperties(props);
            return factory;
        }
        throw new BuilderException("Environment declaration requires a TransactionFactory.");
    }

    private DataSourceFactory dataSourceElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            Properties props = context.getChildrenAsProperties();
            DataSourceFactory factory = (DataSourceFactory) resolveClass(type).newInstance();
            factory.setProperties(props);
            return factory;
        }
        throw new BuilderException("Environment declaration requires a DataSourceFactory.");
    }

    private void typeHandlerElement(XNode parent) throws Exception {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                if ("package".equals(child.getName())) {
                    String typeHandlerPackage = child.getStringAttribute("name");
                    typeHandlerRegistry.register(typeHandlerPackage);
                } else {
                    String javaTypeName = child.getStringAttribute("javaType");
                    String jdbcTypeName = child.getStringAttribute("jdbcType");
                    String handlerTypeName = child.getStringAttribute("handler");
                    Class<?> javaTypeClass = resolveClass(javaTypeName);
                    JdbcType jdbcType = resolveJdbcType(jdbcTypeName);
                    Class<?> typeHandlerClass = resolveClass(handlerTypeName);
                    if (javaTypeClass != null) {
                        if (jdbcType == null) {
                            typeHandlerRegistry.register(javaTypeClass, typeHandlerClass);
                        } else {
                            typeHandlerRegistry.register(javaTypeClass, jdbcType, typeHandlerClass);
                        }
                    } else {
                        typeHandlerRegistry.register(typeHandlerClass);
                    }
                }
            }
        }
    }

    // TODO 这里需要优化
    private void mapperElement(XNode parent) throws Exception {
        /**
         * 定义集合 用来分类放置mybatis的Mapper与XML 按顺序依次遍历
         */
        if (parent != null) {
            //指定在classpath中的mapper文件
            Set<String> resources = new HashSet<>();
            //指向一个mapper接口
            Set<Class<?>> mapperClasses = new HashSet<>();
            setResource(parent, resources, mapperClasses);
            // 依次遍历 首先 resource 然后 mapper
            for (String resource : resources) {
                ErrorContext.instance().resource(resource);
                InputStream inputStream = Resources.getResourceAsStream(resource);
                //TODO
                XMLMapperBuilder mapperParser = new XMLMapperBuilder(inputStream, configuration, resource,
                        configuration.getSqlFragments());
                mapperParser.parse();
            }
            for (Class<?> mapper : mapperClasses) {
                //TODO
                configuration.addMapper(mapper);
            }
        }
    }

    /**
     * 查找mybatis配置文件填充至Set集合
     *
     * @param parent    节点
     * @param resources
     * @param mapper
     * @throws ClassNotFoundException
     */
    private void setResource(XNode parent, Set<String> resources, Set<Class<?>> mapper) throws ClassNotFoundException {
        for (XNode child : parent.getChildren()) {
            if ("package".equals(child.getName())) {
                String mapperPackage = child.getStringAttribute("name");
                ResolverUtil<Class<?>> resolverUtil = new ResolverUtil<>();
                resolverUtil.find(new ResolverUtil.IsA(Object.class), mapperPackage);
                Set<Class<? extends Class<?>>> mapperSet = resolverUtil.getClasses();
                mapper.addAll(mapperSet);
            } else {
                String resource = child.getStringAttribute("resource");
                String url = child.getStringAttribute("url");
                String mapperClass = child.getStringAttribute("class");
                if (resource != null && url == null && mapperClass == null) {
                    resources.add(resource);
                } else if (resource == null && url != null && mapperClass == null) {
                    resources.add(url);
                } else if (resource == null && url == null && mapperClass != null) {
                    Class<?> mapperInterface = Resources.classForName(mapperClass);
                    mapper.add(mapperInterface);
                } else {
                    throw new BuilderException(
                            "A mapper element may only specify a url, resource or class, but not more than one.");
                }
            }
        }
    }

    private boolean isSpecifiedEnvironment(String id) {
        if (environment == null) {
            throw new BuilderException("No environment specified.");
        } else if (id == null) {
            throw new BuilderException("Environment requires an id attribute.");
        } else if (environment.equals(id)) {
            return true;
        }
        return false;
    }

}