spring ibatis Spring怎样集成ibatis项目并实现dao层基类封装
爱笑的berg 人气:0Apache iBatis(现已迁至Google Code下发展,更名为MyBatis)是当前IT项目中使用很广泛的一个半自动ORM框架,区别于Hibernate之类的全自动框架,iBatis对数据库的操作拥有更加灵活的控制,对于那些经常需要调用本地数据库函数自定义SQL语句,或是喜欢自己优化SQL执行效率的开发者来说,iBatis是一个非常不错的选择。
而得到广泛应用的开源企业架构SpringFramework,也很好的将其进行了集成,使得iBatis在 SpringFramework中的使用更加便利、快捷。开发者所要做的就是继承SpringFramework中提供的SqlMapClientDaoSupport类即可。下面将简单介绍使用spring中集成的ibatis进行项目中dao层基类封装,以方便开发。
1、SqlMapClientFactoryBean 的装配
SqlMapClientFactoryBean是SqlMapClientTemplate使用的基础,如果在SpringFramework应用中没有装配SqlMapClientFactoryBean,那么SqlMapClientTemplate将不可用,报空指针错误。其配置信息如下:
<bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean"> <!-- iBatis sqlmap config 文件位置 --> <property name="configLocation"> <value> /WEB-INF/classes/org/bussiness/config/ibatis/SqlMapConfig.xml </value> </property> <!-- 在SpringFramework配置文件中使用的数据源 --> <property name="dataSource"> <ref local="dataSource" /> </property> <!-- 如果需要读写Lob字段,需要注入在SpringFramework配置文件中配置好的Handler,这里是Oracle的数据库 --> <property name="lobHandler" ref="oracleLobHandler"/> </bean>
2、继承使用SqlMapClientDaoSupport类
2.1)首先定义一个IBaseDao接口提供各种场景的查询、修改、删除、分页查询的各种抽象功能方法
package org.biframework.dao.ibatis; import com.ibatis.common.util.PaginatedList; import java.util.List; import org.biframework.exception.DaoException; public abstract interface IBaseDao { public abstract Object getObject(String paramString, Object paramObject) throws DaoException; @SuppressWarnings("unchecked") public abstract List getList(String paramString, Object paramObject) throws DaoException; public abstract PaginatedList getPgntList(String paramString1, Object paramObject, String paramString2) throws DaoException; public abstract PaginatedList getPgntList(String paramString1, Object paramObject, String paramString2, int paramInt) throws DaoException; @SuppressWarnings("unchecked") public abstract List getListUseSameStmt(String paramString, Object[] paramArrayOfObject) throws DaoException; public abstract int update(String paramString, Object paramObject) throws DaoException; public abstract int transUpdateSameOpt(String paramString, Object[] paramArrayOfObject) throws DaoException; public abstract int transUpdate(Object[][] paramArrayOfObject) throws DaoException; @SuppressWarnings("unchecked") public List getList(String statementName, Object parameterObject, int skipResults, int maxResults) throws DaoException; }
备注:该层也可以不写
2.2)继承使用SqlMapClientDaoSupport类并实现IBaseDao接口
package org.biframework.dao.ibatis; import java.util.ArrayList; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.biframework.exception.DaoException; import org.springframework.orm.ibatis.support.SqlMapClientDaoSupport; import com.ibatis.common.util.PaginatedList; public class BaseDao extends SqlMapClientDaoSupport implements IBaseDao { @SuppressWarnings("unused") private static Log log; protected static final int PAGE_SIZE = 15; @SuppressWarnings("unchecked") static Class class$0; /* synthetic field */ public BaseDao() { } /* 使用spring中集成的ibatis实现数据的查询、修改、删除 1)当请求参数被封装为一个普通对象,查询结果为List集合: 使用queryForList返回List 源码方法如下:getSqlMapClientTemplate(),获取SqlMapClientTemplate对象, 参数说明:a、statementName sql声明;b、parameterObject请求参数对象 queryForList方法源码如下 public List queryForList(String statementName, Object parameterObject) throws DataAccessException { executeWithListResult(new SqlMapClientCallback() { private final String val$statementName; private final Object val$parameterObject; public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException { return executor.queryForList(this.val$statementName, this.val$parameterObject); } }); } */ @SuppressWarnings("unchecked") public List getList(String statementName, Object parameterObject) throws DaoException { List list = getSqlMapClientTemplate().queryForList(statementName, parameterObject); return list; } /* 2)当请求参数被封装为一个数组对象时: 即使用数组存放多个传参对象(obj1、obj2...)而后使用相同sql,进行多次查询,将多次查询的结果list1、list2...放到结果集List中) 使用queryForList返回List 封装的方法如下: */ @SuppressWarnings("unchecked") public List getListUseSameStmt(String statementName, Object objectParam[]) throws DaoException { List list = null; List temp = null; if (statementName == null || objectParam == null|| objectParam.length == 0){ return list; }else{ for (int i = 0; i < objectParam.length; i++) { if (list == null){ list = new ArrayList(); temp = getSqlMapClientTemplate().queryForList(statementName,objectParam[i]); } if (temp != null){ list.addAll(temp); } } } return list; } /* 3)当请求参数被封装为一个普通对象,查询结果为Object对象 */ @SuppressWarnings("unchecked") public Object getObject(String statementName, Object parameterObject) throws DaoException { Object result = null; List list = getSqlMapClientTemplate().queryForList(statementName,parameterObject); if (list != null && list.size() > 0){ result = list.get(0); } return result; } /* 4)ibatis-common-2.jar、使用ibatis自身封装的PaginatedList工具类进行分页查询,每页15条数据。 public PaginatedList queryForPaginatedList(String statementName, Object parameterObject, int pageSize) throws DataAccessException { if (((this.sqlMapClient instanceof ExtendedSqlMapClient)) && (((ExtendedSqlMapClient)this.sqlMapClient).getDelegate().getTxManager() == null)) { throw new InvalidDataAccessApiUsageException("SqlMapClient needs to have DataSource to allow for lazy loading - specify SqlMapClientFactoryBean's 'dataSource' property"); } (PaginatedList)execute(new SqlMapClientCallback() { private final String val$statementName; private final Object val$parameterObject; private final int val$pageSize; public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException { return executor.queryForPaginatedList(this.val$statementName, this.val$parameterObject, this.val$pageSize); } }); } */ public PaginatedList getPgntList(String statementName, Object parameterObject, String pageDirection) throws DaoException { PaginatedList list = getSqlMapClientTemplate().queryForPaginatedList( statementName, parameterObject, 15); if ("next".equals(pageDirection)) list.nextPage(); else if ("previous".equals(pageDirection)) list.previousPage(); else if ("first".equals(pageDirection)) list.isFirstPage(); else if ("last".equals(pageDirection)) list.isLastPage(); return list; } /* 4)自己指定分页查询的数量 */ public PaginatedList getPgntList(String statementName, Object parameterObject, String pageDirection, int pageSize) throws DaoException { PaginatedList list = getSqlMapClientTemplate().queryForPaginatedList( statementName, parameterObject, pageSize); if ("next".equals(pageDirection)) { System.out.println("下一页"); list.nextPage(); } else if ("previous".equals(pageDirection)) { System.out.println("上一页"); list.previousPage(); } else if ("first".equals(pageDirection)) { System.out.println("首页"); list.isFirstPage(); } else if ("last".equals(pageDirection)) { System.out.println("末页"); list.isLastPage(); } return list; } /* 5)该方法暂时未理解其主要是处于何种场景使用 */ public int update(String statementName, Object parameterObject) throws DataAccessException { Integer result = (Integer)execute(new SqlMapClientCallback() { private final String val$statementName; private final Object val$parameterObject; public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException { return new Integer(executor.update(this.val$statementName, this.val$parameterObject)); } }); return result.intValue(); } */ public int transUpdate(Object statementAndparameter[][]) throws DaoException { Object statements[] = statementAndparameter[0]; Object parameters[] = statementAndparameter[1]; int result = 0; for (int i = 0; i < statements.length; i++) { String name = (String) statements[i]; Object param = parameters[i]; result += getSqlMapClientTemplate().update(name, param); } return result; } /* 6)请求参数被封装为一个数组对象,返回结果为成功更新的记录数使用spring封装的update方法进行更新操作 */ public int transUpdateSameOpt(String statementName, Object objectParam[]) throws DaoException { int result = 0; if (statementName == null || objectParam == null || objectParam.length == 0) return result; for (int i = 0; i < objectParam.length; i++) result += getSqlMapClientTemplate().update(statementName, objectParam[i]); return result; } /* 7)请求参数被封装为一个普通对象,返回结果为成功更新的记录数 */ public int update(String statementName, Object parameterObject) throws DaoException { int result = getSqlMapClientTemplate().update(statementName, parameterObject); return result; } static { log = LogFactory.getLog(org.biframework.dao.ibatis.BaseDao.class); } /* 8)请求参数被封装为一个普通对象,并对查询的结果记录指定跳跃数和最大结果集 */ @SuppressWarnings("unchecked") public List getList(String statementName, Object parameterObject, int skipResults, int maxResults) throws DaoException { return getSqlMapClientTemplate().queryForList(statementName, parameterObject, skipResults, maxResults); } }
3、进行dao层配置,并进行查询等操作
3.1)所有的dao层都继承BaseDao类
import java.sql.ResultSet; import java.sql.SQLException; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.biframework.dao.ibatis.BaseDao; import org.biframework.exception.DaoException; import org.bussiness.product.detailquery.bo.StPolicyBean; public class StPolicyDao extends BaseDao { protected static Log log = LogFactory.getLog(StPolicyDao.class); @SuppressWarnings("unchecked") public List getStPerm(StPBean param) throws DaoException{ return super.getList("getShortPrem", param); } public Object getStPermCount(StPBean param) throws DaoException{ return super.getObject("getShortPremCount", param); } } }
3.2)进行dao装配 detailQuery-applicationContext.xml
<bean id="nstpDao" class="org.bussiness.product.detailquery.dao.NstPolicyDao"> <property name="dataSource"> <ref bean="dataSource" /> </property> <property name="sqlMapClient"> <ref bean="sqlMapClient" /> </property> </bean>
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