你知道mybatis的分页查询有哪几种实现方式吗?具体是怎样去实现的呢?下面就是要给大家详细的介绍一下这方面的问题。
这里的话分别总结了mybatis5种实现分页查询的方法：
UserMapper.java接口文件
public interface UserMapper
{
//分页查询
public List < User > selectForPage1(int startIndex, int pageSize);
public List < User > selectForPage2(Map < String, Object > map);
public Integer selectCount();
public List < User > selectForPage3(PageBean pageBean);
//分页加模糊查询
public Integer selectCount2(String keywords);
public List < User > selectForPage4(Map < String, Object > map);
}工具类PageBean.java
public class PageBean
{
private Integer currentPage;
private Integer startIndex;
private Integer pageSize = 5;
private Integer totalCount;
private Integer totalPage;
public Integer getCurrentPage()
{
return currentPage;
}
public void setCurrentPage(Integer currentPage)
{
this.currentPage = currentPage;
this.startIndex = (this.currentPage - 1) * this.pageSize;
}
public Integer getPageSize()
{
return pageSize;
}
public void setPageSize(Integer pageSize)
{
this.pageSize = pageSize;
}
public Integer getTotalCount()
{
return totalCount;
}
public void setTotalCount(Integer totalCount)
{
this.totalCount = totalCount;
//计算总页数
this.totalPage = (int) Math.ceil((this.totalCount * 1.0 / this.pageSize));
}
public Integer getTotalPage()
{
return totalPage;
}
public void setTotalPage(Integer totalPage)
{
this.totalPage = totalPage;
}
public Integer getStartIndex()
{
return startIndex;
}
public void setStartIndex(Integer startIndex)
{
this.startIndex = startIndex;
}
}UserMapper.xml文件
在这当中，查询5是模糊加分页查询语句
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace和Mapper接口类名字一样 -->
<mapper namespace="com.gx.mapper.UserMapper">
<!-- 查询1 -->
<select id="selectForPage1" resultType="User">
select * from user limit #{param1},#{param2}
</select>
<!-- 查询2-->
<select id="selectForPage2" resultType="User">
select * from user limit #{startIndex},#{pageSize}
</select>
<!-- 查询3-->
<select id="selectAll" resultType="User">
select * from user
</select>
<!-- 查询总条数-->
<select id="selectCount" resultType="java.lang.Integer">
select count(*) from user
</select>
<!-- 查询4-->
<select id="selectForPage3" resultType="User">
select * from user limit #{startIndex},#{pageSize}
</select>
<!-- 查询5-->
<select id="selectForPage4" resultType="User">
select * from user
where name like "%"#{keywords}"%" or address like "%"#{keywords}"%"
limit #{startIndex},#{pageSize}
</select>
<!-- 模糊查询查询总条数-->
<select id="selectCount2" resultType="java.lang.Integer" parameterType="java.lang.String">
select count(*) from user where name like "%"#{value}"%" or address like "%"#{value}"%"
</select>
</mapper>测试test
在这当中，方法6是模糊加分页查询测试
public class myTest {
SqlSession session = MyBatisUtils.openSession();
UserMapper userMapper = session.getMapper(UserMapper.class);
@Test
public void selectForPage1() {
int currentPage=1;
int pageSize=5;
List
<User> selectForPage = userMapper.selectForPage1((currentPage-1)*pageSize, pageSize);
for (User user : selectForPage) {
System.out.println(user);
}
MyBatisUtils.closeSession(session);
}
@Test
public void selectForPage2() {
int currentPage=1;
int pageSize=5;
Map
<String , Object> map=new HashMap<>();
map.put("startIndex", (currentPage-1)*pageSize);
map.put("pageSize", pageSize);
List
<User> selectForPage = userMapper.selectForPage2(map);
for (User user : selectForPage) {
System.out.println(user);
}
MyBatisUtils.closeSession(session);
}
@Test
public void selectForPage3() {
int currentPage=1;
int pageSize=5;
/**
* 参数1：开始条 偏移量,下标
* 参数2：参数总条数
*/
RowBounds rowBounds = new RowBounds((currentPage-1)*pageSize, pageSize);
//使用mybatis里面提供的api去写的
List
<User> list = session.selectList("com.gx.mapper.UserMapper.selectAll", null, rowBounds);
for (User user : list) {
System.out.println(user);
}
MyBatisUtils.closeSession(session);
}
@Test
public void selectForPage4() {
Integer count = userMapper.selectCount();
System.out.println(count);
int currentPage=1;
int pageSize=5;
Map
<String , Object> map=new HashMap<>();
map.put("startIndex", (currentPage-1)*pageSize);
map.put("pageSize", pageSize);
List
<User> list = userMapper.selectForPage2(map);
for (User user : list) {
System.out.println(user);
}
System.out.println("当前第"+currentPage+"页，共"+count+"条");
MyBatisUtils.closeSession(session);
}
@Test
public void selectForPage5() {
PageBean bean = new PageBean();
bean.setCurrentPage(1);
bean.setPageSize(5);
//查询总条数
Integer count = userMapper.selectCount();
//放到pageBean
bean.setTotalCount(count);
List
<User> list = userMapper.selectForPage3(bean);
for (User user : list) {
System.out.println(user);
}
System.out.println("当前第"+bean.getCurrentPage()+"页，共"+count+"条");
MyBatisUtils.closeSession(session);
}
@Test
public void selectForPage6() {
String keywords="云6";
PageBean bean = new PageBean();
bean.setCurrentPage(1);
bean.setPageSize(5);
//查询总条数
Integer count = userMapper.selectCount2(keywords);
//放到pageBean
bean.setTotalCount(count);
Map
<String , Object> map = new HashMap<>();
map.put("startIndex", bean.getStartIndex());
map.put("pageSize", bean.getPageSize());
map.put("keywords", keywords);
List
<User> list = userMapper.selectForPage4(map);
for (User user : list) {
System.out.println(user);
}
System.out.println("当前第"+bean.getCurrentPage()+"页，共"+count+"条");
MyBatisUtils.closeSession(session);
}
}之前也给大家介绍过mybatis分页插件实现的相关内容，感兴趣的朋友可以去了解一下，除此之外，请多多的关注奇Q工具网吧，更多java常见问题及解决方法可以为你分享呢。
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