一个简单的mybatis封装（二）

基于上一篇的封装，实现一个UserDAO
接口：IUserDAO，也是在mybatis配置中对应的一个mapper接口

package example.dao;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Param;

import example.model.User;

public interface IUserDAO {
	public User findById(int id);
	public User findByName(String name);
	public void addUser(User user);
	public List<User> findUsers(@Param("start")int start, @Param("size")int size);
	public Map<Integer, User> findUserByIds(List<Integer> list);
}

具体实现，继承了AbstractBatisDAO，供业务逻辑层调用。

package example.dao.impl;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.session.SqlSession;

import example.dao.AbstractBatisDAO;
import example.dao.IUserDAO;
import example.model.User;

public class UserDAO extends AbstractBatisDAO implements IUserDAO {

	@Override
	public User findById(final int id) {
		User user = (User) super.process(new AbstractBatisDAO.SqlCaller() {
			public Object doWith(SqlSession session) {
				IUserDAO mapper = session.getMapper(IUserDAO.class);
				return mapper.findById(id);
			}
		});
		return user;
	}

	@Override
	public User findByName(final String name) {
		User user = (User) super.process(new AbstractBatisDAO.SqlCaller() {
			public Object doWith(SqlSession session) {
				IUserDAO mapper = session.getMapper(IUserDAO.class);
				return mapper.findByName(name);
			}
		});
		return user;
	}

	@Override
	public void addUser(final User user) {
		// TODO Auto-generated method stub
		super.process(new AbstractBatisDAO.SqlCaller() {
			public Object doWith(SqlSession session) {
				IUserDAO mapper = session.getMapper(IUserDAO.class);
				mapper.addUser(user);
				return null;
			}
		});
	}

	@Override
	public List<User> findUsers(@Param("start")final int start,
			@Param("size")final int size) {
		List<User> users = (List<User>)super.process(new AbstractBatisDAO.SqlCaller() {
			public Object doWith(SqlSession session) {
				IUserDAO mapper = session.getMapper(IUserDAO.class);
				return mapper.findUsers(start, size);
			}
		});
		return users;
	}

	@Override
	public Map<Integer, User> findUserByIds(final List<Integer> list) {
		Map<Integer, User> users = (Map<Integer, User>)super.process(new AbstractBatisDAO.SqlCaller() {
			public Object doWith(SqlSession session) {
				IUserDAO mapper = session.getMapper(IUserDAO.class);
				return mapper.findUserByIds(list);
			}
		});
		return users;
	}

}

最后是一个调用的例子：

package example;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import example.dao.impl.UserDAO;
import example.model.User;

public class SimpleBatis {
	public static void main(String[] args) throws Exception {
		
		MybatisSessionMgr sessionMgr = new MybatisSessionMgr();
		sessionMgr.init();
		UserDAO userDao = new UserDAO();
		userDao.setSessionMgr(sessionMgr);
		User user = null;
		user = new User();
		user.setName("terry");
		user.setSex((byte)1);
		user.setAge(30);
		userDao.addUser(user);
		System.out.println("sleeping 2 seconds...");
		
		user = userDao.findByName("terry");
		if(user != null) {
			System.out.println("find user:"+user.getName()+", id="+user.getId());
		} else {
			System.out.println("user not found");
		}
		List<Integer> ids = new ArrayList<Integer>(2);
		ids.add(1);
		ids.add(2);
		Map<Integer, User> map = userDao.findUserByIds(ids);
		if(map != null) {
			for(Integer i : map.keySet()) {
				System.out.println("key from map:"+i);
				User u = map.get(i);
				System.out.println(u.getId()+"-"+u.getName()+", sex:"+u.getSex()+", age:"+u.getAge());		
			}
		}
	}
}

SessionMgr，DAO的实现类都是线程安全，可以通过spring IOC将其单例化管理。