Mybatis 通用分页插件
基于 PageHelper 分页
实现步骤：
1.maven坐标
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.1.10</version>
</dependency>
2.加入 plugin 配置
在<environments>之前加入
<plugins>
<plugin interceptor="com.github.pagehelper.PageInterceptor" />
</plugins>
3.PageHelper 对象
查询语句之前调用 PageHelper.startPage 静态方法。
除了 PageHelper.startPage 方法外，还提供了类似用法的 PageHelper.offsetPage 方法。
在你需要进行分页的 MyBatis 查询方法前调用 PageHelper.startPage 静态方法即可，紧跟在这个方法后的第一个 MyBatis 查询方法会被进行分页。
@Test
public void testSelect() throws IOException {
//获取第 1 页，3 条内容
PageHelper.startPage(1,3);
List<Student> studentList = studentDao.selectStudents();
studentList.forEach( stu -> System.out.println(stu));
}
使用PageHelper
接口方法：
List<Student> selectAllStudents();
mapper文件：
<select id="selectAllStudents" resultType="com.lln.vo.Student">
select * from student order by id
</select>
测试类：
@Test
public void testSelectAllStudents(){
//1.获取SqlSession
SqlSession session = MyBatisUtil.getSqlSession();
//2.获取dao的代理
StudentDao dao = session.getMapper(StudentDao.class);
//调用PageHelper的方法
PageHelper.startPage(1,3);
List<Student> students = dao.selectAllStudents();
students.forEach(stu -> System.out.println("stu = "+stu));
//3.关闭SqlSession对象
session.close();
}
运行结果：
Logging initialized using 'class org.apache.ibatis.logging.stdout.StdOutImpl' adapter.
PooledDataSource forcefully closed/removed all connections.
PooledDataSource forcefully closed/removed all connections.
PooledDataSource forcefully closed/removed all connections.
PooledDataSource forcefully closed/removed all connections.
Created connection 209833425.
Returned connection 209833425 to pool.
Cache Hit Ratio [SQL_CACHE]: 0.0
Opening JDBC Connection
Checked out connection 209833425 from pool.
Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@c81cdd1]
==> Preparing: SELECT count(0) FROM student
==> Parameters:
<== Columns: count(0)
<== Row: 7
<== Total: 1
==> Preparing: select * from student order by id LIMIT ?
==> Parameters: 3(Integer)
<== Columns: id, name, email, age
<== Row: 1, 张三, 123@163.com, 18
<== Row: 2, 李四, 456@163.com, 26
<== Row: 3, 王五, 789@163.com, 30
<== Total: 3
stu = Student实体：{
id=1, name='张三', email='[email protected]', age=18}
stu = Student实体：{
id=2, name='李四', email='[email protected]', age=26}
stu = Student实体：{
id=3, name='王五', email='[email protected]', age=30}
Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@c81cdd1]
Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@c81cdd1]
Returned connection 209833425 to pool.