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一、总结了mybatis中五种不同实现分页查询的方法
UserMapper.java接口文件
public interface UserMapper {
//分页查询
public List selectForPage1(int startIndex,int pageSize);
public List selectForPage2(Map map);
public Integer selectCount();
public List selectForPage3(PageBean pageBean);
//分页加模糊查询
public Integer selectCount2(String keywords);
public List selectForPage4(Map 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
其中查询5是模糊加分页查询语句
/p>
PUBLIC “-//mybatis.org//DTD Mapper 3.0//EN”
“http://mybatis.org/dtd/mybatis-3-mapper.dtd”>
select * from user limit #{param1},#{param2}
select * from user limit #{startIndex},#{pageSize}
select * from user
select count(*) from user
select * from user limit #{startIndex},#{pageSize}
select * from user
where name like “%”#{keywords}”%” or address like “%”#{keywords}”%”
limit #{startIndex},#{pageSize}
select count(*) from user where name like “%”#{value}”%” or address like “%”#{value}”%”
测试test
其中方法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 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 map=new HashMap<>();
map.put(“startIndex”, (currentPage-1)*pageSize);
map.put(“pageSize”, pageSize);
List 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 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 map=new HashMap<>();
map.put(“startIndex”, (currentPage-1)*pageSize);
map.put(“pageSize”, pageSize);
List 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 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 map = new HashMap<>();
map.put(“startIndex”, bean.getStartIndex());
map.put(“pageSize”, bean.getPageSize());
map.put(“keywords”, keywords);
List 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);
}
}
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