自定义持久层框架MyORMFramework(三)—框架实现

自定义持久层框架MyORMFramework(三)—框架实现

框架端

定义数据源配置和映射语句实体

Configuration

@Data public class Configuration { private DataSource dataSource; /** * key: statementId value:封装好的mappedStatement对象 */ Map mappedStatementMap = new HashMap<>(); }

MappedStatement

@Data public final class MappedStatement { private String id; /** * sql语句 */ private String sql; /** * 参数值类型 */ private Class parameterType; /** * 返回值类型 */ private Class resultType; }

定义配置文件访问的工具类

public class Resources { /** * 根据配置文件的路径，将配置文件加载成字节输入流，存储在内存中 * * @param path * @return */ public static InputStream getResourceAsSteam(String path) throws IOException { InputStream in = Resources.class.getClassLoader().getResourceAsStream(path); if (in == null) { throw new IOException("找不到资源" + path); } return in; } }

定义SqlSessionFactoryBuilder

public class SqlSessionFactoryBuilder { private Configuration configuration; public SqlSessionFactoryBuilder() { this.configuration = new Configuration(); } public SqlSessionFactory build(InputStream inputStream) throws DocumentException, PropertyVetoException, ClassNotFoundException { //1.dom4j解析配置⽂件，封装Configuration XMLConfigerBuilder xmlConfigerBuilder = new XMLConfigerBuilder(configuration); Configuration configuration = xmlConfigerBuilder.parseConfiguration(inputStream); //2.创建SqlSessionFactory对象（工厂类），生产sqlSession:会话对象 SqlSessionFactory sqlSessionFactory = new DefaultSqlSessionFactory(configuration); return sqlSessionFactory; } }

数据源配置和映射语句解析XMLConfigBuilder、XMLMapperBuilder

XMLConfigBuilder

public class XMLConfigerBuilder { private Configuration configuration; public XMLConfigerBuilder() { this.configuration = new Configuration(); } /** * 该方法就是使用dom4j对配置文件进行解析，封装Configuration */ public Configuration parseConfig(InputStream inputStream) throws DocumentException, PropertyVetoException, IOException, ClassNotFoundException { Document document = new SAXReader().read(inputStream); // Element rootElement = document.getRootElement(); List list = rootElement.selectNodes("//property"); Properties properties = new Properties(); for (Element element : list) { String name = element.attributeValue("name"); String value = element.attributeValue("value"); properties.setProperty(name, value); } //连接池 ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource(); comboPooledDataSource.setDriverClass(properties.getProperty("driverClass")); comboPooledDataSource.setJdbcUrl(properties.getProperty("jdbcUrl")); comboPooledDataSource.setUser(properties.getProperty("username")); comboPooledDataSource.setPassword(properties.getProperty("password")); configuration.setDataSource(comboPooledDataSource); //mapper.xml解析: 拿到路径--字节输入流---dom4j进行解析 List mapperList = rootElement.selectNodes("//mapper"); for (Element element : mapperList) { String mapperPath = element.attributeValue("resource"); InputStream resourceAsSteam = Resources.getResourceAsSteam(mapperPath); XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(configuration); xmlMapperBuilder.parse(resourceAsSteam); } return configuration; } }

XMLMapperBuilder

public class XMLMapperBuilder { private Configuration configuration; public XMLMapperBuilder(Configuration configuration) { this.configuration = configuration; } public void parse(InputStream inputStream) throws DocumentException, ClassNotFoundException { Document document = new SAXReader().read(inputStream); Element rootElement = document.getRootElement(); String namespace = rootElement.attributeValue("namespace"); List select = rootElement.selectNodes("select"); for (Element element : select) { //id的值 String id = element.attributeValue("id"); String parameterType = element.attributeValue("parameterType"); String resultType = element.attributeValue("resultType"); //输⼊参数class Class parameterTypeClass = getClassType(parameterType); //返回结果class Class resultTypeClass = getClassType(resultType); //statementId String key = namespace + "." + id; //sql语句 String textTrim = element.getTextTrim(); //封装 mappedStatement MappedStatement mappedStatement = new MappedStatement(); mappedStatement.setId(id); mappedStatement.setParameterType(parameterTypeClass); mappedStatement.setResultType(resultTypeClass); mappedStatement.setSql(textTrim); //填充 configuration configuration.getMappedStatementMap().put(key, mappedStatement); } } private Class getClassType (String parameterType) throws ClassNotFoundException { Class aClass = Class.forName(parameterType); return aClass; } }

SqlSessionFactory 接口及DefaultSqlSessionFactory 实现类

SqlSessionFactory

public interface SqlSessionFactory { SqlSession openSession(); }

DefaultSqlSessionFactory

public class DefaultSqlSessionFactory implements SqlSessionFactory { private Configuration configuration; public DefaultSqlSessionFactory(Configuration configuration) { this.configuration = configuration; } @Override public SqlSession openSession() { return new DefaultSqlSession(configuration); } }

SqlSession 接口及 DefaultSqlSession 实现类

SqlSession

public interface SqlSession { /** * 查询所有 * * @param statementId * @param params * @param * @return * @throws Exception */ List selectList(String statementId, Object... params) throws Exception; /** * 根据条件查询单个 * * @param statementId * @param params * @param * @return * @throws Exception */ T selectOne(String statementId, Object... params) throws Exception; }

DefaultSqlSession

public class DefaultSqlSession implements SqlSession { private Configuration configuration; public DefaultSqlSession(Configuration configuration) { this.configuration = configuration; } @Override public List selectList(String statementid, Object... params) throws Exception { //将要去完成对simpleExecutor里的query方法的调用 SimpleExecutor simpleExecutor = new SimpleExecutor(); MappedStatement mappedStatement = configuration.getMappedStatementMap().get(statementid); List