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hibernate通用 BaseDao(通用分頁)

基於分頁的通用類 StringUtils 類

package com.eight.dao;

public class StringUtils {
	// 私有的構造方法,保護此類不能在外部例項化
	private StringUtils() {
	}

	/**
	 * 如果字串等於null或去空格後等於"",則返回true,否則返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isBlank(String s) {
		boolean b = false;
		if (null == s || s.trim().equals("")) {
			b = true;
		}
		return b;
	}
	
	/**
	 * 如果字串不等於null或去空格後不等於"",則返回true,否則返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isNotBlank(String s) {
		return !isBlank(s);
	}

}

pageBean 分頁工具類

/**
 * 分頁工具類
 *
 */
public class PageBean {

	private int page = 1;// 頁碼

	private int rows = 3;// 頁大小

	private int total = 0;// 總記錄數

	private boolean pagination = true;// 是否分頁
	// 獲取前臺向後臺提交的所有引數
	private Map<String, String[]> parameterMap;
	// 獲取上一次訪問後臺的url
	private String url;

	/**
	 * 初始化pagebean
	 * 
	 * @param req
	 */
	public void setRequest(HttpServletRequest req) {
		this.setPage(req.getParameter("page"));
		this.setRows(req.getParameter("rows"));
		// 只有jsp頁面上填寫pagination=false才是不分頁
		this.setPagination(!"fasle".equals(req.getParameter("pagination")));
		this.setParameterMap(req.getParameterMap());
		this.setUrl(req.getRequestURL().toString());
	}

	public int getMaxPage() {
		return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
	}

	public int nextPage() {
		return this.page < this.getMaxPage() ? this.page + 1 : this.getMaxPage();
	}

	public int previousPage() {
		return this.page > 1 ? this.page - 1 : 1;
	}

	public PageBean() {
		super();
	}

	public int getPage() {
		return page;
	}

	public void setPage(int page) {
		this.page = page;
	}

	public void setPage(String page) {
		this.page = StringUtils.isBlank(page) ? this.page : Integer.valueOf(page);
	}

	public int getRows() {
		return rows;
	}

	public void setRows(int rows) {
		this.rows = rows;
	}

	public void setRows(String rows) {
		this.rows = StringUtils.isBlank(rows) ? this.rows : Integer.valueOf(rows);
	}

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public void setTotal(String total) {
		this.total = Integer.parseInt(total);
	}

	public boolean isPagination() {
		return pagination;
	}

	public void setPagination(boolean pagination) {
		this.pagination = pagination;
	}

	public Map<String, String[]> getParameterMap() {
		return parameterMap;
	}

	public void setParameterMap(Map<String, String[]> parameterMap) {
		this.parameterMap = parameterMap;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	/**
	 * 獲得起始記錄的下標
	 * 
	 * @return
	 */
	public int getStartIndex() {
		return (this.page - 1) * this.rows;
	}

	@Override
	public String toString() {
		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination
				+ ", parameterMap=" + parameterMap + ", url=" + url + "]";
	}

}

BaseDao

package com.eight.dao;

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

import org.hibernate.Session;
import org.hibernate.query.Query;
import org.omg.CORBA.OBJ_ADAPTER;

/**
 * 作用: 1,將賦值的操作交給basedao處理 2,分頁 a,查詢出條件的總記錄數 b,查詢符合條件的某一頁記錄
 * 
 * @author YGUUU
 *
 */
public class BaseDao {
	/**
	 * 賦值的操作
	 * 
	 * @param query
	 *            預定義物件
	 * @param map
	 *            前臺傳遞過來的引數
	 */
	public void setParameter(Query query, Map<String, Object> map) {
		// query.setParameter("bookName", "%"+book.getBookName()+"%");
		if (map == null || map.size() == 0) {
			return;
		}
		Object value = null;
		for (Map.Entry<String, Object> entry : map.entrySet()) {
			value = entry.getValue();
			if (value instanceof Collection) {
				query.setParameterList(entry.getKey(), (Collection) value);
			} else if (value instanceof Object[]) {
				query.setParameterList(entry.getKey(), (Object[]) value);
			} else {
				query.setParameter(entry.getKey(), value);
			}
		}
	}

	public void ser(Query query, Map<String, Object> map) {
		if (map == null && map.size() == 0) {
			return;
		}
		Object value = null;
		for (Map.Entry<String, Object> entry : map.entrySet()) {
			value = entry.getValue();
			if (value instanceof Collection) {
				query.setParameterList(entry.getKey(), (Collection) value);
			} else if (value instanceof Object[]) {
				query.setParameterList(entry.getKey(), (Object[]) value);
			} else {
				query.setParameter(entry.getKey(), value);
			}
		}
	}

	/**
	 * select * from t_hibernate_book where book_name like '%聖墟%' countSql = select
	 * count(*) from (select * from t_hibernate_book where book_name like '%聖墟%') t
	 * pageSql = sql+" limit ?,?" hibernate中這一步省略
	 * 
	 * hql = from Book where 1=1 and bookName like '%聖墟%' hql = select
	 * bookName,price from Book where 1=1 and bookName like '%聖墟%'
	 * 
	 * 思路: 擷取from後面的sql語句,前面拼接select count(*) from轉成大寫
	 */

	/**
	 * 查詢出條件的總記錄數
	 * 
	 * @param hql
	 * @return
	 */
	public String getCountHql(String hql) {
		int indexOf = hql.toUpperCase().indexOf("FROM");
		return "select count(*) " + hql.substring(indexOf);
	}

	public List executeQuery(Session session, String hql, PageBean pageBean, Map<String, Object> map) {
		if (pageBean != null && pageBean.isPagination()) {
			// select count(*) from t_hibernate_book where book_name like '%聖墟%'
			String countHql = getCountHql(hql);
			Query Countquery = session.createQuery(countHql);
			this.setParameter(Countquery, map);

			// pageBean設定總記錄數,用於分頁
			pageBean.setTotal(Countquery.getSingleResult().toString());

			// 查詢展示的資料
			Query pageQuery = session.createQuery(hql);
			this.setParameter(pageQuery, map);
			pageQuery.setFirstResult(pageBean.getStartIndex());
			pageQuery.setMaxResults(pageBean.getRows());
			return pageQuery.list();
		} else {
			Query query = session.createQuery(hql);
			this.setParameter(query, map);
			return query.list();
		}
	}

}

繼承basedao

package com.five.dao;

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

import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.zking.eight.dao.BaseDao;
import com.zking.eight.dao.PageBean;
import com.zking.eight.dao.StringUtils;
import com.zking.five.entity.Book;
import com.zking.two.util.SessionFactoryUtils;


public class BookDao extends BaseDao{
	
	public List<Book> list1(Book book,PageBean pageBean){
		Session session = SessionFactoryUtils.getSession();
		Transaction transaction = session.beginTransaction();
		String hql="from Book where 1=1";
		if(StringUtils.isNotBlank(book.getBookName())) {
			hql+=" and bookName like :bookName";
		}
		Query query = session.createQuery(hql);
		if(StringUtils.isNotBlank(book.getBookName())) {
			query.setParameter("bookName", "%"+book.getBookName()+"%");
		}
		if(pageBean!=null&&pageBean.isPagination()) {
			query.setFirstResult(pageBean.getStartIndex());
			query.setMaxResults(pageBean.getRows());
		}
		List list = query.list();
		transaction.commit();
		session.close();
		return list;
	}
	
	public List<Book> list2(Book book,PageBean pageBean){
		Session session = SessionFactoryUtils.getSession();
		Transaction transaction = session.beginTransaction();
		Map<String, Object> map=new HashMap<>();
		String hql="from Book where 1=1";
		if(StringUtils.isNotBlank(book.getBookName())) {
			hql+=" and bookName like :bookName";
			map.put("bookName", book.getBookName());
		}
		//沒寫BaseDao前,你上面寫了多少個判斷,下面就要寫多少個判斷加分頁的一個判斷,寫		 	了BaseDao後,直接呼叫這個executeQuery 就行了
		List list = super.executeQuery(session, hql, pageBean, map);
		transaction.commit();
		session.close();
		return list;
	}
	
	
	
	
	public List<Object[]> list3(){
		Session session = SessionFactoryUtils.getSession();
		Transaction transaction = session.beginTransaction();
		Map<String, Object> map=new HashMap<>();
//		String hql="select b.bookName,o.orderNo from Book b,Order o where 1=1";
//		String sql="select b.book_name,o.order_no from t_hibernate_book b,t_hibernate_order o where 1=1";
		String sql="select * from book_order";
		
//		List list = session.createQuery(hql).list();
		List list = session.createSQLQuery(sql).list();
		
		transaction.commit();
		session.close();
		return list;
	}
	
}

測試方法

private BookDao bookDao=new BookDao();
	
	@Test
	public void testList1() {
		PageBean pageBean=new PageBean();
//		pageBean.setPage(2);
		Book book=new Book();
		book.setBookName("斗羅大陸");
		List<Book> list1 = this.bookDao.list1(book, pageBean);
		for (Book b : list1) {
			System.out.println(b);
		}
	}
	
	@Test
	public void testList2() {
		PageBean pageBean=new PageBean();
//		pageBean.setPage(2);
		Book book=new Book();
		book.setBookName("斗羅大陸");
		List<Book> list1 = this.bookDao.list2(book, pageBean);
		for (Book b : list1) {
			System.out.println(b);
		}
	}
	
	@Test
	public void testList3() {
		PageBean pageBean=new PageBean();
		pageBean.setPage(2);
		Book book=new Book();
//		book.setBookName("斗羅大陸");
		List<Object[]> list1 = this.bookDao.list3();
		for (Object[] b : list1) {
			System.out.println(Arrays.toString(b));
		}
	}
	

原生sql hql實現不了的功能,可以考慮使用原生sql 1、多表(5+)聯查 2、未配置對映檔案中關係

public List<Object[]> list3(){
		Session session = SessionFactoryUtils.getSession();
		Transaction transaction = session.beginTransaction();
		Map<String, Object> map=new HashMap<String, Object>();
//		String hql="select b.bookName,o.OrderNo from Book b,Order o where 1=1";
//		String sql="select b.book_name,o.order_no from t_hibernate_book b,t_hibernate_Order o where 1=1";//原生態sql
		String sql="select * from book_order";//檢視對映
		
		
		
//		List list = session.createQuery(hql).list();
		List list = session.createSQLQuery(sql).list();
		
		transaction.commit();
		session.close();
		return list;
	}

檢視對映 場景 select * from 3表聯查 建立檢視 建立檢視實體類(注:實體類要實現 Serializable介面)

package com.zking.eight.entity;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

import com.zking.five.entity.Category;

public class BookOrder implements Serializable{
	private Integer book_id;
	private Integer order_id;
	private String bookName;
	private String OrderNo;
	
	
	
	public Integer getBook_id() {
		return book_id;
	}
	public void setBook_id(Integer book_id) {
		this.book_id = book_id;
	}
	public Integer getOrder_id() {
		return order_id;
	}
	public void setOrder_id(Integer order_id) {
		this.order_id = order_id;
	}
	public String getOrderNo() {
		return OrderNo;
	}
	public void setOrderNo(String orderNo) {
		OrderNo = orderNo;
	}
	
	
	
	public String getBookName() {
		return bookName;
	}
	public void setBookName(String bookName) {
		this.bookName = bookName;
	}
	public BookOrder(Integer book_id, Integer order_id, String bookName, String orderNo) {
		super();
		this.book_id = book_id;
		this.order_id = order_id;
		this.bookName = bookName;
		OrderNo = orderNo;
	}
	public BookOrder() {
		super();
	}
	@Override
	public String toString() {
		return "BookOrder [book_id=" + book_id + ", order_id=" + order_id + ", bookName=" + bookName + ", OrderNo="
				+ OrderNo + "]";
	}
}

*.hbm.xml

?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
   
    	<class table="bookorder" name="com.zking.eight.entity.BookOrder">
    		<composite-id>
    			<key-property name="book_id" type="java.lang.Integer" column="book_id"></key-property>
    			<key-property name="order_id" type="java.lang.Integer" column="order_id"></key-property>
    		</composite-id>
    		<property name="bookName" type="java.lang.String" column="book_name"></property>
    		<property name="OrderNo" type="java.lang.String" column="order_no"></property>
    		
    	</class>
    </hibernate-mapping>

配置hibernate.cfg.xml檔案

 <mapping resource="com/zking/eight/entity/BookOrder.hbm.xml"/>
public List<BookOrder> list4(){
		Session session = SessionFactoryUtils.getSession();
		Transaction transaction = session.beginTransaction();
//		Map<String, Object> map=new HashMap<String, Object>();
		String hql="from BookOrder";
		
		List list = session.createQuery(hql).list();
		
		transaction.commit();
		session.close();
		return list;
	}