在Java中将映射器添加到myBatis配置

问题描述

我想从XML配置迁移到Java配置.

I want to migrate from XML configuration to Java configuration.

sqlSessionFactory.getConfiguration().setEnvironment(new Environment("development", new org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory(), getDataSouroce()));

我设法用Java配置替换了所有<environments>部分(我已经从XML配置文件中删除了<environments>)，但是我无法摆脱:

I managed to replace all <environments> section with Java configuration (I have removed <environments> from XML configuration file), but I can't get rid of:

 <mappers><mapper resource="mailbox/db/map/FileMapper.xml"/> </mappers>

我试图写:

但有例外:

SqlSession sqlSession = MyBatisConnectionFactory.instance.getSqlSessionFactory().openSession();

    FileExample fe = new FileExample();
    Criteria f = fe.createCriteria().andIdBetween(0L, 5L);
    FileMapper mapper = (FileMapper) sqlSession.getMapper(FileMapper.class);
    List<File> allRecords = mapper.selectByExample(fe);

// Mapped Statements collection does not contain value for mailbox.db.dao.FileMapper.selectByExample

推荐答案

我在下面的抽象映射器工厂中使用DbUtil.getInstance().getDataSource()和registerMappers()是关键点.

I am using below abstract mapper factory where DbUtil.getInstance().getDataSource() and registerMappers() are the key points.

public abstract class AbstractMapperFactory implements MapperFactory {

    private ThreadLocal<SqlSessionManager> sessionManagerThreadLocal = new ThreadLocal<SqlSessionManager>();

    public <T> T getMapper(Class<T> clazz) throws DaoException {
        if(sessionManagerThreadLocal.get() == null) {
            initialize();
        }
        return sessionManagerThreadLocal.get().getMapper(clazz);
    }

    public void closeSession() {
        if(sessionManagerThreadLocal.get() != null) {
            sessionManagerThreadLocal.get().close();
            sessionManagerThreadLocal.remove();
        }
    }

    private void initialize() throws DaoException {
        Environment environment = new Environment("env", new ManagedTransactionFactory(), DbUtil.getInstance().getDataSource());
        Configuration configuration = new Configuration(environment);
        registerMappers(configuration);
        sessionManagerThreadLocal.set(SqlSessionManager.newInstance(new SqlSessionFactoryBuilder().build(configuration)));
    }

    protected abstract void registerMappers(Configuration configuration);

}

DbUtil.getInstance().getDataSource()负责获取java.sql.DataSource实例，无论它是托管实例还是简单实例.

Where DbUtil.getInstance().getDataSource() is responsible for getting the java.sql.DataSource instance, whether it is managed or simple.

registerMappers()是一种抽象方法，子类可以使用以下代码注册其映射器:

registerMappers() is an abstract method where subclass can register their mappers using code like below:

protected void registerMappers(Configuration configuration) {
    configuration.addMapper(PartMapper.class);
    configuration.addMapper(StatusMapper.class);
    configuration.addMapper(NoteTypeMapper.class);
    configuration.addMapper(AssetTypeMapper.class);
}

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