预算编报管理系统 Day8 Ajax 事物不回滚问题解决 加载静态模板的代码 根据spring用法重新编写dao层

1.学习使用ajax

代码:

 function req(){
        var xmlhttp;
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","response.html",true);
xmlhttp.send();
}

如果申请的是html文件 , 则返回的response是body里面的内容

2.事物不回滚问题解决方法

mysql 默认引擎不支持事务,所以在后台无论如何回滚都不会回滚,因此需要设置支持事务的引擎才能实现回滚

参考链接: https://blog.youkuaiyun.com/u011622226/article/details/43985929

package DAO;

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

import javax.transaction.Transaction;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;

import Bean.BaseBean;
import Bean.Budget;

public  class BaseDao {
	protected SessionFactory sessionFactory;
	
	public BaseDao() {
		// TODO Auto-generated constructor stub
	}
	public void save(BaseBean bb){
		sessionFactory.getCurrentSession().save(bb);
	}
	public void save(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.save(bb);
		}
	}
	
	public void delete(BaseBean bb){
		sessionFactory.getCurrentSession().delete(bb);
	}
	public void delete(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.delete(bb);
		}
	}
	public void update(BaseBean bb){
		sessionFactory.getCurrentSession().update(bb);
	}
	public void update(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.update(bb);
		}
	}
	public void saveOrUpdate(BaseBean bb){
		sessionFactory.getCurrentSession().saveOrUpdate(bb);
	}
	public void saveOrUpdate(List<BaseBean> bbs){
		//sessionFactory.getCurrentSession().saveOrUpdate(bb);
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.saveOrUpdate(bb);
		}
	}
	
	
	public SessionFactory getSessionFactory() {
		return sessionFactory;
	}
	public void setSessionFactory(SessionFactory sessionFactory) {
		this.sessionFactory = sessionFactory;
	}


}

3.加载静态模板

package Service;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

import javax.servlet.http.HttpServletResponse;

/*
 * 这个类适用于加载已经写好的模板文件的静态部分head部分,
 * js代码以及css部分和一些body部分
 * 但是同一模板文件的不同部分可能要分开存放,当需要插入一些
 * 可变部分的时候,需要从其中分开,并将分开后的各部分用含有
 * 一定意义的名字标记,方便加载
 */
public class HTMLWriter {

	public HTMLWriter() {
		// TODO Auto-generated constructor stub
	}
	
	//将一个文件加载到response里面
	public static void load(HttpServletResponse response,String staticfile) throws IOException{
		File f = new File(staticfile);
		String content = "";
		String line = "";
		BufferedReader br=new BufferedReader( new FileReader(f)); 
		while((line=br.readLine())!=null){
			content+=line+"\r\n";
		}
		br.close();
		response.getOutputStream().println(content);
		
	}

}

4.重新写dao层

在bean包里:

1.首先定义一个bean的基类BaseBean 不声明方法和变量

2.然后让所有映射表的类都继承basebean

3.在里面定义变量和setter getter

在dao包里:

1.首先定义一个BaseDao类

代码如下:

package DAO;

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

import javax.transaction.Transaction;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;

import Bean.BaseBean;
import Bean.Budget;

public  class BaseDao {
	protected SessionFactory sessionFactory;
	
	public BaseDao() {
		// TODO Auto-generated constructor stub
	}
	public void save(BaseBean bb){
		sessionFactory.getCurrentSession().save(bb);
	}
	public void save(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.save(bb);
		}
	}
	
	public void delete(BaseBean bb){
		sessionFactory.getCurrentSession().delete(bb);
	}
	public void delete(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.delete(bb);
		}
	}
	public void update(BaseBean bb){
		sessionFactory.getCurrentSession().update(bb);
	}
	public void update(List<BaseBean> bbs){
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.update(bb);
		}
	}
	public void saveOrUpdate(BaseBean bb){
		sessionFactory.getCurrentSession().saveOrUpdate(bb);
	}
	public void saveOrUpdate(List<BaseBean> bbs){
		//sessionFactory.getCurrentSession().saveOrUpdate(bb);
		Session session = sessionFactory.getCurrentSession();
		for (BaseBean bb:bbs){
			session.saveOrUpdate(bb);
		}
	}
	
	
	public SessionFactory getSessionFactory() {
		return sessionFactory;
	}
	public void setSessionFactory(SessionFactory sessionFactory) {
		this.sessionFactory = sessionFactory;
	}


}

以上定义的方法可以在各个子类中通用

2.令所有表的到类继承basedao

以Budget_DAO 为例:代码如下

package DAO;

import java.util.ArrayList;

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

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.orm.hibernate4.HibernateTransactionManager;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.support.DefaultTransactionDefinition;

import Bean.BaseBean;
import Bean.Budget;

@Repository  
@Transactional
public class Budget_DAO extends BaseDao{
	
	protected List<Budget>  selectAll(){
		String hql ="from Budget";
		return (List<Budget>)sessionFactory.getCurrentSession().createQuery(hql).list();
		//return null;
		
	}

public List<Budget> queryBudget(List<Map<String,Object>> params) {
		
		//Configuration config = new Configuration();
		//SessionFactory sessionfactory = config.configure().buildSessionFactory();
		//Session session = sessionfactory.openSession();
		
		//List<Budget> budgetResult = new ArrayList<Budget>();
		StringBuilder sb = new StringBuilder();
		sb.append("from Budget where 1 = 1");
		if(params != null && params.size() > 0){
			for(int i = 0 ; i < params.size() ; i++){
				Map<String,Object> map = params.get(i);
				Object value = map.get("value");
				if(value instanceof String)value = "'"+value+"'";
				sb.append(" and " + map.get("name") + " " +map.get("rela") + value);
			}
		}
		Query query = sessionFactory.getCurrentSession().createQuery(sb.toString());
		
		List <Budget> budgetResult = query.list();
		// TODO Auto-generated method stub
		return budgetResult;
	}

	
	public static void main(String args[])
	{
		
		ApplicationContext actx = new ClassPathXmlApplicationContext("applicationContext.xml");
		Budget_DAO bd = (Budget_DAO) actx.getBean("budgetDao");
		List <Map<String,Object>> params = new ArrayList<Map<String ,Object>>();
		Map<String,Object> param = new HashMap<String, Object>();
		param.put("name", "state");
		param.put("rela", "=");
		param.put("value", "w");
		params.add(param);
		List<Budget> l = bd.queryBudget(params);
		//System.out.println(l.size());
		
		for(BaseBean b :l){
			System.out.println(b);
		}
		
		
		
		 HibernateTransactionManager manager = (HibernateTransactionManager) actx.getBean("transactionManager");
		 DefaultTransactionDefinition def = new DefaultTransactionDefinition();
		 def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW); // 事物隔离级别，开启新事务
		 TransactionStatus status = manager.getTransaction(def); // 获得事务状态
		
		 Budget budget =  new Budget();
		 budget.setBudg_id("999");
		 budget.setDate("1200-02-29");
		 budget.setDep_id("102");
		 budget.setMoney(9000);
		 budget.setState("通过");
		 budget.setType_id("01");
		 budget.setUser_id("10203040");
		 try{
		 //bd.delete(l);
			
			
			for (Budget  b:l){
				bd.delete(b);
			}
			//bd.save(budget);

		
		//bd.sessionFactory.getCurrentSession().getTransaction().commit();
		manager.commit(status);
		}catch(Exception e){
			e.printStackTrace();
			//manager.rollback(status);
			
			System.out.println("erroe");
		}

	}
	

}

在父类中的save update , delete的返回均为void 因此可以通用

但是select有返回类型,最主要的是hql = "from Budget" 部分 不相同,因此,需要在每个子类中定义select方法,以及query方法