试着写了个MyBatis的GenericDao

shenzhang

Interface：
package com.xlaohe1.example.dao;
import java.io.Serializable;
import java.util.List;
public interface GenericDao<T, PK extends Serializable> {
public List<T> findAll();
public void add(T t);
public void delete(PK id);
public T findById(PK id);
public void update(T t);
}


Implments：

package com.xlaohe1.example.dao.impl;
import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import com.xlaohe1.example.dao.GenericDao;
import com.xlaohe1.example.util.Util;
public class GenericDaoImpl<T, PK extends Serializable> implements GenericDao<T, PK> {
/*private static SqlSession session;
static {
session = Util.getSqlSessionFactory().openSession();
}*/
Class<T> clazz;
@SuppressWarnings("unchecked")
public GenericDaoImpl() {
clazz = (Class<T>)((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[0];
}
@SuppressWarnings("unchecked")
public List<T> findAll() {
SqlSession session = Util.getSqlSessionFactory().openSession();
List<T> lists = null;
try {
StringBuffer sb = new StringBuffer(clazz.getName());
sb.append("Mapper").append(".find");
lists = session.selectList(sb.toString());
} catch (Exception e) {
e.printStackTrace();
}finally {
session.close();
}
return lists;
}
public void add(T t) {
SqlSession session = Util.getSqlSessionFactory().openSession();
try {
StringBuffer sb = new StringBuffer(clazz.getName());
sb.append("Mapper").append(".insertOne");
session.insert(sb.toString(), t);
session.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
session.close();
}
}

public void delete(PK id) {
SqlSession session = Util.getSqlSessionFactory().openSession();
try {
StringBuffer sb = new StringBuffer(clazz.getName());
sb.append("Mapper").append(".del");
session.insert(sb.toString(), id);
session.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
session.close();
}
}

@SuppressWarnings("unchecked")
public T findById(PK id) {
SqlSession session = Util.getSqlSessionFactory().openSession();
T t = null;
try {
StringBuffer sb = new StringBuffer(clazz.getName());
sb.append("Mapper").append(".selectOne");
t = (T)session.selectOne(sb.toString(), id);
} catch (Exception e) {
e.printStackTrace();
}finally {
session.close();
}
return t;
}
public void update(T t) {
SqlSession session = Util.getSqlSessionFactory().openSession();
try {
StringBuffer sb = new StringBuffer(clazz.getName());
sb.append("Mapper").append(".update");
session.update(sb.toString(), t);
session.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
session.close();
}
}

}