内容简介:mybatis-config.xmlDeptMapper.xmlDept.java
MyBatis
配置
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.huifer</groupId> <artifactId>mybatisBook</artifactId> <version>1.0-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.13</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.4</version> </dependency> </dependencies> <build> <plugins> <plugin> <inherited>true</inherited> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> </build> </project>
mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/dy_java?serverTimezone=UTC&rewriteBatchedStatements=true&useUnicode=true&characterEncoding=utf8"/> <property name="username" value="root"/> <property name="password" value="root"/> </dataSource> </environment> </environments> <mappers> <mapper resource="DeptMapper.xml"/> </mappers> </configuration>
测试
DeptMapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="Dept"> <insert id="insertDept" > INSERT INTO dept (dname, loc) VALUES (#{dname} , #{loc}); </insert> </mapper>
Dept.java
package com.huifer.mybatis; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; /** * 描述: * * @author huifer * @date 2019-02-21 */ @Data @AllArgsConstructor @NoArgsConstructor public class Dept { private Long id; private String dname; private String loc; }
测试类
public class Demo { public static void main(String[] args) throws Exception { Dept dept = new Dept(); dept.setDname("技术部"); dept.setLoc("oc"); InputStream is = Resources.getResourceAsStream("mybatis-config.xml"); SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is); SqlSession session = factory.openSession(); session.insert("insertDept", dept); session.commit(); session.close(); } }
查询表
至此初步配置完成
执行过程
graph TD start[获取mybatis.config.xml] --> conditionA[SqlSessionFactory] conditionA --> |xml 解析成 org.apache.ibatis.session.Configuration | conditionB[接收SqlSessionFactory] conditionB --> |org.apache.ibatis.session.defaults.DefaultSqlSessionFactory.openSessionFromDataSource| conditionC[ SqlSession] conditionC --> |org.apache.ibatis.session.defaults.DefaultSqlSession insert方法 update方法| conditionD[insert方法] conditionD --> | org.apache.ibatis.mapping.MappedStatement sqlSource属性 | conditionE[mapper 定位] conditionE --> | org.apache.ibatis.executor.SimpleExecutor doUpdate方法 stmt|conditionF[数据绑定到具体sql] conditionF --> |org.apache.ibatis.executor.statement.PreparedStatementHandler update方法 提交| conditionG[传输sql] conditionG -->|commit| stop
session
获取mybatils-config.xml 配置 解析xml标签
-
- org.apache.ibatis.session.defaults.DefaultSqlSessionFactory
private SqlSession openSessionFromDataSource(ExecutorType execType, TransactionIsolationLevel level, boolean autoCommit) { Transaction tx = null; DefaultSqlSession var8; try { Environment environment = this.configuration.getEnvironment(); TransactionFactory transactionFactory = this.getTransactionFactoryFromEnvironment(environment); tx = transactionFactory.newTransaction(environment.getDataSource(), level, autoCommit); Executor executor = this.configuration.newExecutor(tx, execType); var8 = new DefaultSqlSession(this.configuration, executor, autoCommit); } catch (Exception var12) { this.closeTransaction(tx); throw ExceptionFactory.wrapException("Error opening session. Cause: " + var12, var12); } finally { ErrorContext.instance().reset(); } return var8; }
insert
org.apache.ibatis.session.defaults.DefaultSqlSession
public int insert(String statement, Object parameter) { return this.update(statement, parameter); } public int update(String statement, Object parameter) { int var4; try { this.dirty = true; MappedStatement ms = this.configuration.getMappedStatement(statement); var4 = this.executor.update(ms, this.wrapCollection(parameter)); } catch (Exception var8) { throw ExceptionFactory.wrapException("Error updating database. Cause: " + var8, var8); } finally { ErrorContext.instance().reset(); } return var4; }
ms 对象
doUpdate
org.apache.ibatis.executor.SimpleExecutor
public int doUpdate(MappedStatement ms, Object parameter) throws SQLException { Statement stmt = null; int var6; try { Configuration configuration = ms.getConfiguration(); StatementHandler handler = configuration.newStatementHandler(this, ms, parameter, RowBounds.DEFAULT, (ResultHandler)null, (BoundSql)null); stmt = this.prepareStatement(handler, ms.getStatementLog()); var6 = handler.update(stmt); } finally { this.closeStatement(stmt); } return var6; }
update
org.apache.ibatis.executor.statement.PreparedStatementHandler
public int update(Statement statement) throws SQLException { PreparedStatement ps = (PreparedStatement)statement; ps.execute(); int rows = ps.getUpdateCount(); Object parameterObject = this.boundSql.getParameterObject(); KeyGenerator keyGenerator = this.mappedStatement.getKeyGenerator(); keyGenerator.processAfter(this.executor, this.mappedStatement, ps, parameterObject); return rows; }
Mapper
<mappers> <!--<mapper resource="DeptMapper.xml"/>--> <package name="com.huifer.mybatis.dao"/> </mappers>
获取过程源码
-
org.apache.ibatis.builder.xml.XMLConfigBuilder 使用parseConfiguration 方法将 mybatis-config.xml 中的mappers 标签内容获取到 mapperElement具体执行获取内容 ,作用将mappers添加到configuration 中
private void parseConfiguration(XNode root) { try { this.propertiesElement(root.evalNode("properties")); Properties settings = this.settingsAsProperties(root.evalNode("settings")); this.loadCustomVfs(settings); this.loadCustomLogImpl(settings); this.typeAliasesElement(root.evalNode("typeAliases")); this.pluginElement(root.evalNode("plugins")); this.objectFactoryElement(root.evalNode("objectFactory")); this.objectWrapperFactoryElement(root.evalNode("objectWrapperFactory")); this.reflectorFactoryElement(root.evalNode("reflectorFactory")); this.settingsElement(settings); this.environmentsElement(root.evalNode("environments")); this.databaseIdProviderElement(root.evalNode("databaseIdProvider")); this.typeHandlerElement(root.evalNode("typeHandlers")); this.mapperElement(root.evalNode("mappers")); } catch (Exception var3) { throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + var3, var3); } } private void mapperElement(XNode parent) throws Exception { if (parent != null) { Iterator var2 = parent.getChildren().iterator(); while(true) { while(var2.hasNext()) { XNode child = (XNode)var2.next(); String resource; if ("package".equals(child.getName())) { resource = child.getStringAttribute("name"); this.configuration.addMappers(resource); } else { resource = child.getStringAttribute("resource"); String url = child.getStringAttribute("url"); String mapperClass = child.getStringAttribute("class"); XMLMapperBuilder mapperParser; InputStream inputStream; if (resource != null && url == null && mapperClass == null) { ErrorContext.instance().resource(resource); inputStream = Resources.getResourceAsStream(resource); mapperParser = new XMLMapperBuilder(inputStream, this.configuration, resource, this.configuration.getSqlFragments()); mapperParser.parse(); } else if (resource == null && url != null && mapperClass == null) { ErrorContext.instance().resource(url); inputStream = Resources.getUrlAsStream(url); mapperParser = new XMLMapperBuilder(inputStream, this.configuration, url, this.configuration.getSqlFragments()); mapperParser.parse(); } else { if (resource != null || url != null || mapperClass == null) { throw new BuilderException("A mapper element may only specify a url, resource or class, but not more than one."); } Class<?> mapperInterface = Resources.classForName(mapperClass); this.configuration.addMapper(mapperInterface); } } } return; } } }
当前Configuration 下的mappedStatements 属性
-
org.apache.ibatis.binding.MapperRegistry addMapper 方法,作用将解析到的接口对象放到configuration 中 ,一个接口只能注册一次
public <T> void addMapper(Class<T> type) { if (type.isInterface()) { if (this.hasMapper(type)) { throw new BindingException("Type " + type + " is already known to the MapperRegistry."); } boolean loadCompleted = false; try { this.knownMappers.put(type, new MapperProxyFactory(type)); MapperAnnotationBuilder parser = new MapperAnnotationBuilder(this.config, type); parser.parse(); loadCompleted = true; } finally { if (!loadCompleted) { this.knownMappers.remove(type); } } } }
-
org.apache.ibatis.builder.annotation.MapperAnnotationBuilder parse方法
loadXmlResource 来确认加载具体的xml文件
public void parse() { String resource = this.type.toString(); if (!this.configuration.isResourceLoaded(resource)) { this.loadXmlResource(); this.configuration.addLoadedResource(resource); this.assistant.setCurrentNamespace(this.type.getName()); this.parseCache(); this.parseCacheRef(); Method[] methods = this.type.getMethods(); Method[] var3 = methods; int var4 = methods.length; for(int var5 = 0; var5 < var4; ++var5) { Method method = var3[var5]; try { if (!method.isBridge()) { this.parseStatement(method); } } catch (IncompleteElementException var8) { this.configuration.addIncompleteMethod(new MethodResolver(this, method)); } } } this.parsePendingMethods(); } private void loadXmlResource() { if (!this.configuration.isResourceLoaded("namespace:" + this.type.getName())) { String xmlResource = this.type.getName().replace('.', '/') + ".xml"; InputStream inputStream = this.type.getResourceAsStream("/" + xmlResource); if (inputStream == null) { try { inputStream = Resources.getResourceAsStream(this.type.getClassLoader(), xmlResource); } catch (IOException var4) { } } if (inputStream != null) { XMLMapperBuilder xmlParser = new XMLMapperBuilder(inputStream, this.assistant.getConfiguration(), xmlResource, this.configuration.getSqlFragments(), this.type.getName()); xmlParser.parse(); } } }
根据 loadXmlResource 中下面这行得知 , PojoMapper.xml 要和 PojoMapperInterface 放在一个路径下
String xmlResource = this.type.getName().replace('.', '/') + ".xml";
具体sql
-
org.apache.ibatis.builder.xml.XMLStatementBuilder parseStatementNode 方法解析 sql 语句
<select id="deptFindById" resultType="com.huifer.mybatis.pojo.Dept" parameterType="java.lang.Long"> select * from dept where dept.id=#{deptno}; </select>
public void parseStatementNode() { String id = this.context.getStringAttribute("id"); String databaseId = this.context.getStringAttribute("databaseId"); if (this.databaseIdMatchesCurrent(id, databaseId, this.requiredDatabaseId)) { Integer fetchSize = this.context.getIntAttribute("fetchSize"); Integer timeout = this.context.getIntAttribute("timeout"); String parameterMap = this.context.getStringAttribute("parameterMap"); String parameterType = this.context.getStringAttribute("parameterType"); Class<?> parameterTypeClass = this.resolveClass(parameterType); String resultMap = this.context.getStringAttribute("resultMap"); String resultType = this.context.getStringAttribute("resultType"); String lang = this.context.getStringAttribute("lang"); LanguageDriver langDriver = this.getLanguageDriver(lang); Class<?> resultTypeClass = this.resolveClass(resultType); String resultSetType = this.context.getStringAttribute("resultSetType"); StatementType statementType = StatementType.valueOf(this.context.getStringAttribute("statementType", StatementType.PREPARED.toString())); ResultSetType resultSetTypeEnum = this.resolveResultSetType(resultSetType); String nodeName = this.context.getNode().getNodeName(); SqlCommandType sqlCommandType = SqlCommandType.valueOf(nodeName.toUpperCase(Locale.ENGLISH)); boolean isSelect = sqlCommandType == SqlCommandType.SELECT; boolean flushCache = this.context.getBooleanAttribute("flushCache", !isSelect); boolean useCache = this.context.getBooleanAttribute("useCache", isSelect); boolean resultOrdered = this.context.getBooleanAttribute("resultOrdered", false); XMLIncludeTransformer includeParser = new XMLIncludeTransformer(this.configuration, this.builderAssistant); includeParser.applyIncludes(this.context.getNode()); this.processSelectKeyNodes(id, parameterTypeClass, langDriver); SqlSource sqlSource = langDriver.createSqlSource(this.configuration, this.context, parameterTypeClass); String resultSets = this.context.getStringAttribute("resultSets"); String keyProperty = this.context.getStringAttribute("keyProperty"); String keyColumn = this.context.getStringAttribute("keyColumn"); String keyStatementId = id + "!selectKey"; keyStatementId = this.builderAssistant.applyCurrentNamespace(keyStatementId, true); Object keyGenerator; if (this.configuration.hasKeyGenerator(keyStatementId)) { keyGenerator = this.configuration.getKeyGenerator(keyStatementId); } else { keyGenerator = this.context.getBooleanAttribute("useGeneratedKeys", this.configuration.isUseGeneratedKeys() && SqlCommandType.INSERT.equals(sqlCommandType)) ? Jdbc3KeyGenerator.INSTANCE : NoKeyGenerator.INSTANCE; } this.builderAssistant.addMappedStatement(id, sqlSource, statementType, sqlCommandType, fetchSize, timeout, parameterMap, parameterTypeClass, resultMap, resultTypeClass, resultSetTypeEnum, flushCache, useCache, resultOrdered, (KeyGenerator)keyGenerator, keyProperty, keyColumn, databaseId, langDriver, resultSets); } }
-
还原sql方法
SqlSource sqlSource = langDriver.createSqlSource(this.configuration, this.context, parameterTypeClass);
-
org.apache.ibatis.scripting.defaults.RawSqlSource RawSqlSource方法
public RawSqlSource(Configuration configuration, String sql, Class<?> parameterType) { SqlSourceBuilder sqlSourceParser = new SqlSourceBuilder(configuration); Class<?> clazz = parameterType == null ? Object.class : parameterType; this.sqlSource = sqlSourceParser.parse(sql, clazz, new HashMap()); }
-
org.apache.ibatis.builder.SqlSourceBuilder parse方法还原成sql语句
public SqlSource parse(String originalSql, Class<?> parameterType, Map<String, Object> additionalParameters) { SqlSourceBuilder.ParameterMappingTokenHandler handler = new SqlSourceBuilder.ParameterMappingTokenHandler(this.configuration, parameterType, additionalParameters); GenericTokenParser parser = new GenericTokenParser("#{", "}", handler); String sql = parser.parse(originalSql); return new StaticSqlSource(this.configuration, sql, handler.getParameterMappings()); }
- 最后看一下 sqlSource
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持 码农网
猜你喜欢:- [闹着玩-2]spring-mvc 主要流程
- 【源码阅读】AndPermission源码阅读
- ReactNative源码解析-初识源码
- 【源码阅读】Gson源码阅读
- Spring源码系列:BeanDefinition源码解析
- istio 源码 – Citadel 源码分析 (原创)
本站部分资源来源于网络,本站转载出于传递更多信息之目的,版权归原作者或者来源机构所有,如转载稿涉及版权问题,请联系我们。
Head First Rails
David Griffiths / O'Reilly Media / 2008-12-30 / USD 49.99
Figure its about time that you hop on the Ruby on Rails bandwagon? You've heard that it'll increase your productivity exponentially, and allow you to created full fledged web applications with minimal......一起来看看 《Head First Rails》 这本书的介绍吧!