Spring+Hibernate 复杂查询分页

最新推荐文章于 2025-04-01 14:43:20 发布

xingzengwu

最新推荐文章于 2025-04-01 14:43:20 发布

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分类专栏： Java 文章标签： spring hibernate import string user null

本文链接：https://blog.youkuaiyun.com/xingzengwu/article/details/816612

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本文介绍了一个简单的分页包装类及其实现方式，该类能够处理基本的分页逻辑，并配合UserDao接口完成复杂的查询需求。文章通过具体示例展示了如何进行分页查询，包括设置页面大小、计算总页数等关键步骤。

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网上多很多有分页例子，要么不全，要么不能满足复杂查询的要求，下面是本人写的一个初版，给大家参考。

/**分页包装类

很简单 :)

package com.xing.cms.model.util;

public class Pager {
private int totalPages = 0;
private int totalObjects = 0;
private int pageNumber = 1;
private int pageSize = 3;
private boolean pageAble = true;

private int firstResult;

public void calc(){
totalPages = totalObjects % pageSize == 0 ? totalObjects
/ pageSize : totalObjects / pageSize + 1;

firstResult = (pageNumber - 1) * pageSize;
}

public boolean isPageAble() {
return pageAble;
}

public void setPageAble(boolean pageAble) {
this.pageAble = pageAble;
}

public int getTotalObjects() {
return totalObjects;
}

public void setTotalObjects(int param) {
this.totalObjects = param;
}

public int getTotalPages() {
return totalPages;
}

public void setTotalPages(int param) {
this.totalPages = param;
}

public int getPageNumber() {
return pageNumber;
}

public void setPageNumber(int pageNumber) {
this.pageNumber = pageNumber;
}

public int getPageSize() {
return pageSize;
}

public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}

public String toString(){
return("/ntotalPages:" + totalPages +
"/ntotalObjects:" + totalObjects +
"/npageNumber:" + pageNumber +
"/npageSize:" + pageSize +
"/npageAble:" + pageAble +
"/nfirstResult:" + firstResult);
}

public int getFirstResult() {
return firstResult;
}

public void setFirstResult(int firstResult) {
this.firstResult = firstResult;
}
}

/*UserDao 接口*/

package com.xing.cms.model.dao;

import java.util.List;

import com.xing.cms.model.businessobject.User;
import com.xing.cms.model.util.Pager;

public interface UserDao {
public abstract boolean save(User model);
public abstract boolean update(User model);
public abstract User get(int id);
public abstract boolean delete(int id);
public abstract void truncate();
public abstract boolean delete(int[] id);
public abstract List<User> find(String[][] searchPara,Pager pager);
public abstract List<User> find(String[][] searchPara);
}

/*UserDao实现*/

package com.xing.cms.model.dao.impl;

import java.sql.SQLException;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Hibernate;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
//import org.hibernate.criterion.Expression;
import org.hibernate.criterion.Restrictions;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projections;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.xing.cms.model.businessobject.User;
import com.xing.cms.model.dao.UserDao;
import com.xing.cms.model.util.GeneralTool;
import com.xing.cms.model.util.Pager;

public class UserDaoImpl extends HibernateDaoSupport implements UserDao {

private JdbcTemplate jdbcTemplate;// Spring Injection

public UserDaoImpl() {
super();
}

public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}

public void setJdbcTemplate(JdbcTemplate param) {
this.jdbcTemplate = param;
}

@SuppressWarnings("unchecked")
public List<User> find(final String[][] searchPara, final Pager pager) {

return (List<User>) this.getHibernateTemplate().execute(
    new HibernateCallback() {
     public Object doInHibernate(Session session)
       throws SQLException, HibernateException {
      Criteria ca_count = null;

      if(pager.isPageAble())
       ca_count = session.createCriteria(User.class);//不能避免,需要查询两次数据库,这个获取总数

      Criteria ca = session.createCriteria(User.class);

      if(searchPara != null){
       ca.setProjection(null);
      for (int i = 0; i < searchPara.length; i++) {

       if (searchPara[i][1].equalsIgnoreCase("=")) {
        if(pager.isPageAble())
         ca_count.add(Restrictions.eq(searchPara[i][0], searchPara[i][2]));
        ca.add(Restrictions.eq(searchPara[i][0], searchPara[i][2]));
       } else if (searchPara[i][1].equalsIgnoreCase("like")) {
        if(pager.isPageAble())
         ca_count.add(Restrictions.like(searchPara[i][0], searchPara[i][2],MatchMode.ANYWHERE));
        ca.add(Restrictions.like(searchPara[i][0], searchPara[i][2],MatchMode.ANYWHERE));

       }

      }
      }

      List ret_list;

if (pager.isPageAble()) {

       pager.setTotalObjects(((Integer) (ca_count
         .setProjection(Projections.rowCount())
         .uniqueResult())).intValue()); //获取Count

       pager.calc();

       ca.addOrder(Order.desc("UID"));
       ca.setFirstResult(pager.getFirstResult());
       ca.setMaxResults(pager.getPageSize());
       ret_list = ca.list();

      } else {
       ca.addOrder(Order.desc("UID"));
       ret_list = ca.list();

      }

      return ret_list;
     }
    });
}

// ......其它方法略去

/*测试类*/

package test;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.test.AbstractTransactionalDataSourceSpringContextTests;
import com.xing.cms.model.businessobject.User;
import com.xing.cms.model.dao.DocumentDao;
import com.xing.cms.model.dao.UserDao;
import com.xing.cms.model.util.HtmlGenerator;
import com.xing.cms.model.util.Pager;
import com.xing.cms.model.util.UtilXml;
import com.xing.cms.action.UserAction;

public class TestSpring extends AbstractTransactionalDataSourceSpringContextTests
{
private Log logger = LogFactory.getLog(TestSpring.class);

public String[] getConfigLocations() {
String[] config = new String[]{"applicationContext.xml"};
return config;
}

public void testUserAction() throws Exception{

UserDao dao = (UserDao)applicationContext.getBean("userDao");
assertTrue(dao!=null);
User user = (User)applicationContext.getBean("user");
assertTrue(user!=null);
Pager pager = (Pager)applicationContext.getBean("pager");
assertTrue(pager!=null);
UserAction action = (UserAction)applicationContext.getBean("userAction");
assertTrue(action!=null);

//clear all first
dao.truncate();

//super.setComplete();

//add
for(int i=0;i<20;i++)
{
   User u = new User();
   u.setGID(1);
   u.setUsername("xzw_"+i);
   u.setPassword("abcd");
   dao.save(u);
}

//no pager

/*
assertEquals(0,dao.find(
    new String[][]{
      new String[]{"username","=","xzw"}
    }
).size());
assertEquals(20,dao.find(null).size());
*/

//with pager
//action.getPager().setPageSize(9);
//10 11 12 ... 19 + 1 = 11

/*分页，取第一页，前4 条，应该返回4*/
action.getPager().setPageSize(4);
assertEquals(4,dao.find(new String[][]{
    new String[]{"username","like","xzw_1"}
},action.getPager()).size());

/*不分页，则取全部的，应该返回20*/
action.getPager().setPageAble(false);
action.getPager().setPageSize(4);
assertEquals(11,dao.find(new String[][]{
new String[]{"username","like","xzw_1"}
},action.getPager()).size());

}
}