Spring如何整合ibatis專案並實現dao層基類封裝
Apache iBatis(現已遷至Google Code下發展,更名為MyBatis)是當前IT專案中使用很廣泛的一個半自動ORM框架,區別於Hibernate之類的全自動框架,iBatis對資料庫的操作擁有更加靈活的控制,對於那些經常需要呼叫本地資料庫函式自定義SQL語句,或是喜歡自己優化SQL執行效率的開發者來說,iBatis是一個非常不錯的選擇。
而得到廣泛應用的開源企業架構SpringFramework,也很好的將其進行了整合,使得iBatis在 SpringFramework中的使用更加便利、快捷。開發者所要做的就是繼承SpringFramework中提供的SqlMapClientDaoSupport類即可。下面將簡單介紹使用spring中整合的ibatis進行專案中dao層基類封裝,以方便開發。
1、SqlMapClientFactoryBean 的裝配
SqlMapClientFactoryBean是SqlMapClientTemplate使用的基礎,如果在SpringFramework應用中沒有裝配SqlMapClientFactoryBean,那麼SqlMapClientTemplate將不可用,報空指標錯誤。其配置資訊如下:
<bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean"> <!-- iBatis sqlmap config 檔案位置 --> <property name="configLocation"> <value> /WEB-INF/classes/org/bussiness/config/ibatis/SqlMapConfig.xml </value> </property> <!-- 在SpringFramework配置檔案中使用的資料來源 --> <property name="dataSource"> <ref local="dataSource" /> </property> <!-- 如果需要讀寫Lob欄位,需要注入在SpringFramework配置檔案中配置好的Handler,這裡是Oracle的資料庫 --> <property name="lobHandler" ref="oracleLobHandler"/> </bean>
2、繼承使用SqlMapClientDaoSupport類
2.1)首先定義一個IBaseDao介面提供各種場景的查詢、修改、刪除、分頁查詢的各種抽象功能方法
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,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; }
備註:該層也可以不寫
2.2)繼承使用SqlMapClientDaoSupport類並實現IBaseDao介面
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$0; /* synthetic field */ public BaseDao() { } /* 使用spring中整合的ibatis實現資料的查詢、修改、刪除 1)當請求引數被封裝為一個普通物件,查詢結果為List集合: 使用queryForList返回List 原始碼方法如下:getSqlMapClientTemplate(),獲取SqlMapClientTemplate物件, 引數說明:a、statementName sql宣告;b、parameterObject請求引數物件 queryForList方法原始碼如下 public List queryForList(String statementName,Object parameterObject) throws DataAccessException { executeWithListResult(new SqlMapClientCallback() { private final String val$statementName; private final Object val$parameterObject; public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException { return executor.queryForList(this.val$statementName,this.val$parameterObject); } }); } */ @SuppressWarnings("unchecked") public List getList(String statementName,Object parameterObject) throws DaoException { List list = getSqlMapClientTemplate().queryForList(statementName,parameterObject); return list; } /* 2)當請求引數被封裝為一個數組物件時: 即使用陣列存放多個傳參物件(obj1、obj2...)而後使用相同sql,進行多次查詢,將多次查詢的結果list1、list2...放到結果集List中) 使用queryForList返回List 封裝的方法如下: */ @SuppressWarnings("unchecked") public List getListUseSameStmt(String statementName,Object objectParam[]) throws DaoException { List list = null; List temp = null; if (statementName == null || objectParam == null|| objectParam.length == 0){ return list; }else{ for (int i = 0; i < objectParam.length; i++) { if (list == null){ list = new ArrayList(); temp = getSqlMapClientTemplate().queryForList(statementName,objectParam[i]); } if (temp != null){ list.addAll(temp); } } } return list; } /* 3)當請求引數被封裝為一個普通物件,查詢結果為Object物件 */ @SuppressWarnings("unchecked") public Object getObject(String statementName,Object parameterObject) throws DaoException { Object result = null; List list = getSqlMapClientTemplate().queryForList(statementName,parameterObject); if (list != null && list.size() > 0){ result = list.get(0); } return result; } /* 4)ibatis-common-2.jar、使用ibatis自身封裝的PaginatedList工具類進行分頁查詢,每頁15條資料。 public PaginatedList queryForPaginatedList(String statementName,int pageSize) throws DataAccessException { if (((this.sqlMapClient instanceof ExtendedSqlMapClient)) && (((ExtendedSqlMapClient)this.sqlMapClient).getDelegate().getTxManager() == null)) { throw new InvalidDataAccessApiUsageException("SqlMapClient needs to have DataSource to allow for lazy loading - specify SqlMapClientFactoryBean's 'dataSource' property"); } (PaginatedList)execute(new SqlMapClientCallback() { private final String val$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$pageSize); } }); } */ public PaginatedList getPgntList(String statementName,String pageDirection) throws DaoException { PaginatedList list = getSqlMapClientTemplate().queryForPaginatedList( statementName,parameterObject,15); if ("next".equals(pageDirection)) list.nextPage(); else if ("previous".equals(pageDirection)) list.previousPage(); else if ("first".equals(pageDirection)) list.isFirstPage(); else if ("last".equals(pageDirection)) list.isLastPage(); return list; } /* 4)自己指定分頁查詢的數量 */ public PaginatedList getPgntList(String statementName,String pageDirection,int pageSize) throws DaoException { PaginatedList list = getSqlMapClientTemplate().queryForPaginatedList( statementName,pageSize); if ("next".equals(pageDirection)) { System.out.println("下一頁"); list.nextPage(); } else if ("previous".equals(pageDirection)) { System.out.println("上一頁"); list.previousPage(); } else if ("first".equals(pageDirection)) { System.out.println("首頁"); list.isFirstPage(); } else if ("last".equals(pageDirection)) { System.out.println("末頁"); list.isLastPage(); } return list; } /* 5)該方法暫時未理解其主要是處於何種場景使用 */ public int update(String statementName,Object parameterObject) throws DataAccessException { Integer result = (Integer)execute(new SqlMapClientCallback() { private final String val$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)請求引數被封裝為一個數組物件,返回結果為成功更新的記錄數使用spring封裝的update方法進行更新操作 */ 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)請求引數被封裝為一個普通物件,返回結果為成功更新的記錄數 */ 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)請求引數被封裝為一個普通物件,並對查詢的結果記錄指定跳躍數和最大結果集 */ @SuppressWarnings("unchecked") public List getList(String statementName,int maxResults) throws DaoException { return getSqlMapClientTemplate().queryForList(statementName,skipResults,maxResults); } }
3、進行dao層配置,並進行查詢等操作
3.1)所有的dao層都繼承BaseDao類
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)進行dao裝配 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>
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。