配置文件加载

public class Resources {

    /**
     * 根据path加载配置文件
     * @param path 配置文件路径
     * @return InputStream
     */
    public static InputStream getResourceAsStream(String path){
        ClassLoader classLoader = Resources.class.getClassLoader();
        return classLoader.getResourceAsStream(path);
    }
}

public Configuration parseConfig(InputStream in) throws Exception {
    Document document = new SAXReader().read(in);
    //<configuration>
    Element rootElement = document.getRootElement();
    List<Element> 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);
    }

    MysqlDataSource dataSource = new MysqlDataSource();
    dataSource.setUrl(properties.getProperty("url"));
    dataSource.setUser(properties.getProperty("username"));
    dataSource.setPassword(properties.getProperty("password"));
    configuration.setDataSource(dataSource);
    //解析mapper.xml
    //拿到路径
    List<Element> mapperList = rootElement.selectNodes("//mappers");
    //获得流并解析
    for (Element element : mapperList) {
        String mapperPath = element.attributeValue("resource");
        InputStream mapperStream = Resources.getResourceAsStream(mapperPath);
        XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(configuration);
        xmlMapperBuilder.parse(mapperStream);
    }
    return configuration;
}

public void parse(InputStream inputStream) throws Exception {
    Document document = new SAXReader().read(inputStream);
    Element rootElement = document.getRootElement();
    String namespace = rootElement.attributeValue("namespace");
    List<Element> selectList = rootElement.selectNodes("//select");
    for (Element element : selectList) {
        //获取每个属性
        String id = element.attributeValue("id");
        String resultType = element.attributeValue("resultType");
        String paramType = element.attributeValue("paramType");
        String sqlText = element.getTextTrim();
        //封装到MappedStatement
        MappedStatement statement = new MappedStatement();
        statement.setId(id);
        statement.setResultType(resultType);
        statement.setParamType(paramType);
        statement.setSql(sqlText);
        String key = namespace + "." + id;
        //保存在map中
        configuration.getMappedStatementMap().put(key, statement);
    }
}