MyBatis06（分页查询）

目录结构：

配置几乎和前面Mybatis03一样。

mappers不一样：StudentMapper：

import java.util.List;
import java.util.Map;
import org.apache.ibatis.session.RowBounds;
import com.model.Student;

public interface StudentMapper {
public List<Student> findStudents(RowBounds rowBounds);

public List<Student> findStudents2(Map<String,Object> map);

}

StudentMapper.xml：

<?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">
<mapper namespace="com.mappers.StudentMapper">
<!--
    1，size:表示缓存cache中能容纳的最大元素数。默认是1024；
    2，flushInterval:定义缓存刷新周期，以毫秒计；
      3，eviction:定义缓存的移除机制；默认是LRU(least recently userd，最近最少使用),还有FIFO(first in first out，先进先出)
      4，readOnly:默认值是false，假如是true的话，缓存只能读。
     -->
<cache size="1024" flushInterval="60000" eviction="LRU" readOnly="false"/>

<resultMap type="Student" id="StudentResult">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="age" column="age"/>
</resultMap>

<select id="findStudents" resultMap="StudentResult" flushCache="false" useCache="true">
select * from t_student
</select>

<select id="findStudents2" parameterType="Map" resultMap="StudentResult">
select * from t_student
<if test="start!=null and size!=null">
limit #{start},#{size}
</if>
</select>

</mapper> 

测试类：

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


import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;


import com.mappers.StudentMapper;
import com.model.Student;
import com.util.SqlSessionFactoryUtil;

public class StudentTest {
private static Logger logger=Logger.getLogger(StudentTest3.class);
private SqlSession sqlSession=null;
private StudentMapper studentMapper=null;

/**
* 测试方法前调用
* @throws Exception
*/
@Before
public void setUp() throws Exception {
sqlSession=SqlSessionFactoryUtil.openSession();
studentMapper=sqlSession.getMapper(StudentMapper.class);
}


/**
* 测试方法后调用
* @throws Exception
*/
@After
public void tearDown() throws Exception {
sqlSession.close();
}

@Test
public void testFindStudent(){
logger.info("查询学生");
//开始为0  每页几条3条
int offset=0,limit=4;
RowBounds rowBounds=new RowBounds(offset,limit);
List<Student> studentList=studentMapper.findStudents(rowBounds);
for(Student student:studentList){
System.out.println(student);
}
}

@Test
public void testFindStudent2(){
logger.info("查询学生");

Map<String,Object> map=new HashMap<String,Object>();

               //从第几条开始索引，序号要+1

               //显示查询的size大小

map.put("start", 2);
map.put("size", 3);
List<Student> studentList=studentMapper.findStudents2(map);
for(Student student:studentList){
System.out.println(student);
}
}
}