基于Spring+Hibernate的通用增删改查的实现方法

最新推荐文章于 2023-01-12 17:40:45 发布

最新推荐文章于 2023-01-12 17:40:45 发布 · 966 阅读

文章标签：

#Hibernate #Spring #Bean #SQL #DAO

基于Spring+Hibernate的通用增删改查的实现方法

王保政

Msn:baozhengw999@hotmail.com

QQ:29803446

一、设计方案

1.1 名词解释：

业务服务层：业务服务层引用了数据访问层接口DAO，业务服务层的类名一般是按Service作为后缀，业务服务层具体实现类可以按ServiceImpl命名。业务服务层类都可以在Spring配置文件中进行配置。

服务定位器：ServiceLocator是一个服务定位器，也可以说是业务服务层的门面类，此服务定位器提供了静态的方法，通过静态的方法可调用所有的业务服务层接口，ServiceLocator封装了读取Spring配置文件的方法，在JSP或控制层及业务服务层都可以通过ServiceLocator.getXXXService().业务方法()的格式来引用业务服务层提供的方法，例如在JSP中调用一个插入的方法，格式：

ServiceLocator.getDBSupportService().insert(entity,null);//entity为一个继承了AbstractEntity实体变量。

使用ServiceLocator，不需要自己书写读取Spring配置文件的方法来调用spring bean,而且通过ServiceLocator调用的业务逻辑类在spring配置文件中都是按单例配置的，不用的request引用的是同一个内存实例对象，这样可以大大提高系统的性能。

1.2 设计说明

名词解释中简单谈了ServiceLocator和Service层，Service层的bean是要调用Dao层的，Service Bean有一个Dao的属性，这个属性是通过构造注入的方式配置的，所以在Service的构造方法中应该有对dao的赋值语句，建议Service类的Dao属性字段不要按照设值注入的方式，因为我们不希望通过service.getXXXDao()的方式直接引用到Dao层。

在上面的设计图中IDBSupportService是业务服务层接口，DBSupportServiceImpl是业务服务层接口的实现类。IDBSupportService中定义了与数据库操作相关的通用的增删改查等方法。

DAO层的设计是这样的，IBaseDao声明了增删改查方法，BaseHibernateDao抽象类实现了增删改查的通用方法，这个类继承了org.springframework.orm.hibernate3.support.HibernateDaoSupport，这个类提供了很多Spring框架自带的数据库操作相关的模板方法。

AbstractEntity是一个抽象实体类，所有数据库表对应的实体类都要继承这个抽象实体类。

二、Spring配置文件

（1）acegisecurityContext.xml :这个文件与acegi权限相关，本文暂不介绍。

（2）datasource.xml定义了数据源及hibernate参数和映射文件：

<?xml version="1.0" encoding="GB2312"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

<bean id="mysqlds"

class="org.springframework.jndi.JndiObjectFactoryBean">

<value>java:comp/env/jdbc/mysql</value>

</property>

</bean>

<bean id="sessionMysqlFactory"

class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">

</property>

<list>

<!—为节省篇幅，只列出一个hbm.xml文件-->

<value>

org/apache/easframework/core/entity/OlapReportChart.hbm.xml

</value>

</list>

</property>

<props>

<prop key="hibernate.c3p0.validate">false</prop>

org.hibernate.dialect.MySQLDialect

</prop>

<prop key="hibernate.show_sql">false</prop>

org.hibernate.hql.ast.ASTQueryTranslatorFactory

</prop>

</props>

</property>

</bean>

<bean id="hibernateMysqlTemplate"

class="org.springframework.orm.hibernate3.HibernateTemplate">

</property>

</bean>

</beans>

（3） core-service.xml，此文件配置业务逻辑类，其中<ref bean="hibernateMysqlTemplate"/>引用的是datasource.xml中配置的bean。

<?xml version="1.0" encoding="GB2312"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

<constructor-arg><ref local="IBaseDao"/></constructor-arg>

</bean>

<constructor-arg><ref local="IBaseDao"/></constructor-arg>

</bean>

</property>

</bean>

</beans>

三、ServiceLocator的代码：

package org.apache.easframework.core.service;

import org.apache.log4j.Logger;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import org.apache.easframework.core.service.ISysConfig;

public class ServiceLocator {

private static final Logger log = Logger.getLogger(ServiceLocator.class);

private static ApplicationContext context;

public static final ServiceLocator thisService = new ServiceLocator(); //单例类

private static final String[] xmlFiles = new String[] {

"/core-service.xml", "/datasource.xml" ,"/system-config.xml"};

//public static ServiceLocator getInstance()

//{

// return thisService;

//}

/**

* 系统配置组件

* @return

public static ISysConfig getSysConfigService() {

String beanName = "ISysConfig";

ISysConfig service = (ISysConfig) getBeanService(beanName);

return service;

}

public static INodeService getNodeService()

{

String beanName ="INodeService";

INodeService service = (INodeService)getBeanService(beanName);

return service;

}

public static IDBSupportService getDBSupportService() {

String beanName = "IDBSupportService";

IDBSupportService service = (IDBSupportService) getBeanService(beanName);

return service;

}

private static IService getBeanService(String serviceName) {

IService bean = null;

try {

if (context == null) {

context = new ClassPathXmlApplicationContext(xmlFiles);

}

bean = (IService) context.getBean(serviceName);

} catch (Exception e) {

log.error("获取Service Bean对象失败！");

log.error(e.getMessage());

e.printStackTrace();

}

return bean;

}

四、DBSupportServiceImpl增删改查业务逻辑实现类代码:

package org.apache.easframework.core.service.impl;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.apache.easframework.core.dao.IBaseDao;

import org.apache.easframework.core.entity.AbstractEntity;

import org.apache.easframework.core.pageloader.IPageLoader;

import org.apache.easframework.core.pageloader.PageLoaderHibernateImpl;

import org.apache.easframework.core.pageloader.PageLoaderInfo;

import org.apache.easframework.core.service.IDBSupportService;

import org.apache.log4j.Logger;

import org.hibernate.criterion.DetachedCriteria;

public class DBSupportServiceImpl implements IDBSupportService

{

private static final Logger logger = Logger .getLogger(DBSupportServiceImpl.class);

private IBaseDao defaultDao;

/**

* 使用这种方式为了在Spring配置文件中按构造注入的方式实例化Dao,因为不希望外部调用通过getDao方法来间接引用Dao的方法

* 如果使用setter注入，则需要提供defaultDao的set和get方法

* @param dao

public DBSupportServiceImpl(IBaseDao dao)

{

logger.info("Dao构造注入!!!");

this.defaultDao = dao;

}

public void delete(AbstractEntity entity, HttpServletRequest request) throws Exception {

this.defaultDao.delete(entity);

}

public void deleteById(String entityClassName, String keyFieldName, Object keyFieldValue, HttpServletRequest request) throws Exception {

this.defaultDao.deleteById(entityClassName, keyFieldName, keyFieldValue);

}

public void deleteByIds(String entityClassName, String fieldName, Object[] pkIds, HttpServletRequest request) throws Exception {

this.defaultDao.deleteByIds(entityClassName, fieldName, pkIds);

}

public List findAll(String entityClassName, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findAll(entityClassName);

return list;

}

public List findByDetachedCriteria(DetachedCriteria criteria, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findByDetachedCriteria(criteria);

return list;

}

public List findByHqlQuery(String hql, HttpServletRequest request) throws Exception

{

List list = this.defaultDao.findByHqlQuery(hql);

return list;

}

public AbstractEntity findById(String entityClassName, String keyFieldName, Object keyFieldValue, HttpServletRequest request) throws Exception {

AbstractEntity entity = this.defaultDao.findById(entityClassName, keyFieldName, keyFieldValue);

return entity;

}

public List findLabelValueBean(String sql, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findLabelValueBean(sql);

return list;

}

public List findListByFieldValue(String entityClassName, String fieldName, Object fieldValue, boolean isSortAsc, String sortFieldName, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findListByFieldValue(entityClassName, fieldName, fieldValue, isSortAsc, sortFieldName);

return list;

}

public List findPage(String entityClassName, String hqlWhere, int currentPage, int linePerPage, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findPage(entityClassName, hqlWhere, currentPage, linePerPage);

return list;

}

public List findSimilarEntities(AbstractEntity conditionEntity, HttpServletRequest request) throws Exception {

List list = this.defaultDao.findSimilarEntities(conditionEntity);

return list;

}

public Object findSingleValueByHql(String hql, HttpServletRequest request) throws Exception {

Object obj = this.defaultDao.findSingleValueByHql(hql);

return obj;

}

public Object findSingleValueBySql(String sql, HttpServletRequest request) throws Exception {

Object obj = this.defaultDao.findSingleValueBySql(sql);

return obj;

}

public void insert(AbstractEntity entity, HttpServletRequest request) throws Exception {

this.defaultDao.insert(entity);

}

public void saveOrUpdate(AbstractEntity entity, HttpServletRequest request) throws Exception {

this.defaultDao.saveOrUpdate(entity);

}

public void update(AbstractEntity entity, HttpServletRequest request) throws Exception {

this.defaultDao.update(entity);

}

public void updateHql(String hql, HttpServletRequest request) throws Exception {

this.defaultDao.updateHql(hql);

}

public void updateSql(String sql, HttpServletRequest request) throws Exception {

this.defaultDao.updateSql(sql);

}

五、BaseHibernateDao.java

package org.apache.easframework.core.dao;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import org.apache.easframework.core.entity.AbstractEntity;

import org.apache.log4j.Logger;

import org.hibernate.Query;

import org.hibernate.Session;

import org.hibernate.criterion.DetachedCriteria;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

public abstract class BaseHibernateDao extends HibernateDaoSupport implements IBaseDao {

private static final Logger logger = Logger

.getLogger(BaseHibernateDao.class);

public void insert(AbstractEntity entity) {

getHibernateTemplate().save(entity);

}

public void delete(AbstractEntity entity) {

getHibernateTemplate().delete(entity);

}

public AbstractEntity findById(String entityClassName, String keyFieldName,

Object keyFieldValue) throws Exception {

AbstractEntity entity = null;

String sql = "";

if (keyFieldValue instanceof java.lang.String) {

// String型测试通过

sql = "from " + entityClassName + " as vo where vo." + keyFieldName

+ " = '" + keyFieldValue + "'";

} else {

// 数值型的未测试

sql = "from " + entityClassName + " as vo where vo." + keyFieldName

+ " = " + String.valueOf(keyFieldValue) + " ";

}

List list = getHibernateTemplate().find(sql);

if (list.size() > 0)

entity = ((AbstractEntity) list.get(0));

return entity;

}

public List findListByFieldValue(String entityClassName,

String keyFieldName, Object keyFieldValue, boolean isSortAsc,

String sortFieldName) throws Exception {

String sSort = "asc";

if (isSortAsc == false)

sSort = "desc";

String sql = "";

if (keyFieldValue instanceof java.lang.String) {

// String型测试通过

sql = "from " + entityClassName + " as vo where vo." + keyFieldName

+ " = '" + keyFieldValue + "' order by " + sortFieldName

+ " " + sSort;

} else {

// 数值型的未测试

sql = "from " + entityClassName + " as vo where vo." + keyFieldName

+ " = " + String.valueOf(keyFieldValue) + " order by "

+ sortFieldName + " " + sSort;

}

List list = getHibernateTemplate().find(sql);