Mybatis实现数据库分页查询

Mybatis提供一个RowBounds类型，在查询指定RowBounds参数对象可以控制查询记录的起点和数量。
此案例在之前代码基础上执行：
http://blog.csdn.net/u013821825/article/details/51620371

1、SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-config.dtd">
<configuration>
    <environments default="environment">
        <environment id="environment">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/test" />
                <property name="username" value="root" />
                <property name="password" value="root" />
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="org/xsx/entity/EmpSQL.xml" />
    </mappers>
</configuration>

2、实体类和其映射接口

package org.xsx.entity;

public class Emp {
    private Integer id;
    private String name;
    private Integer age;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }


}


package org.xsx.entity;

import java.util.List;

public interface EmpMapper{

    public void addEmp(Emp emp);

    public void updateEmp(Emp emp);

    public Emp findById(int id);

    public void deleteById(int id);

    public List<Emp> findAll();
}

3、EmpSQL.xml配置wenjian

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<mapper namespace="org.xsx.entity.EmpMapper">

<insert id="addEmp" parameterType="org.xsx.entity.Emp">
insert into emp (id,name,age) 
    values (#{id},#{name},#{age})
</insert>

<update id="updateEmp" parameterType="org.xsx.entity.Emp">
    update emp set name=#{name},age=#{age} where id=#{id}
</update>

<select id="findById" parameterType="int" resultType="org.xsx.entity.Emp">
    select name,age from emp where id=#{id}
</select>

<delete id="deleteById" parameterType="int">
    delete from emp where id=#{id}
</delete>

<select id="findAll" resultType="org.xsx.entity.Emp">
    select id,name,age from emp
</select>
</mapper>

4、测试方法

package org.xsx.test;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import org.xsx.entity.Emp;

public class TestEmp extends MybatisHelper {

    static{
        conf =  "SqlMapConfig.xml";
    }

    @Test
    public void testDatasource() throws Exception{
        String conf = "SqlMapConfig.xml";
        Reader reader = Resources.getResourceAsReader(conf);
        //SessionFactoryBuilder对象
        SqlSessionFactoryBuilder builder  = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(reader);

        //Session
        SqlSession session = factory.openSession();

        System.out.println(session);
        session.close();
    }

    @Test
    public void testAddEmp() throws Exception{
// String conf = "SqlMapConfig.xml";
// Reader reader = Resources.getResourceAsReader(conf);
// //SessionFactoryBuilder对象
// SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
// SqlSessionFactory factory = builder.build(reader);

        //Session
        SqlSession session = factory.openSession();

        Emp emp = new Emp();
        emp.setId(4);
        emp.setName("da");
        emp.setAge(91);

        session.insert("addEmp", emp);
        session.commit();
        session.close();
    }

    @Test
    public void testUpdate(){
        //Session
                SqlSession session = factory.openSession();

                Emp emp = (Emp)session.selectOne("findById", 3);
                emp.setId(3);
                emp.setName("ccc");
                emp.setAge(100);

                session.update("updateEmp", emp);
                session.commit();
                session.close();
    }


    @Test
    public void testFindById(){
        //Session
                SqlSession session = factory.openSession();

                Emp emp = (Emp)session.selectOne("findById", 3);
                System.out.println(emp.getName());
                session.close();
    }

    @Test
    public void testDeleteById(){
        //Session
                SqlSession session = factory.openSession();

                session.delete("deleteById", 4);
                session.commit();
                session.close();
    }

    @Test
    public void testRowBounds(){
        //Session
        SqlSession session = factory.openSession();

        int offset = 0;//起点
        int limit=3;//数量

        RowBounds rowBounds = new RowBounds(offset, limit);
        List<Emp> list = session.selectList("findAll", null, rowBounds);

        for(Emp e:list){
            System.out.println(e.getId()+"--"+e.getName()+"--"+e.getAge());
        }

        session.close();
    }
}

5、静态加载类准备SqlSession资源

package org.xsx.test;

import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;

public class MybatisHelper {
    public static String conf ;
    public static Reader reader;
    public static SqlSessionFactoryBuilder builder;
    public static SqlSessionFactory factory;

    @Before
    public void startMybatis() throws Exception{
        reader = Resources.getResourceAsReader(conf);
        builder = new SqlSessionFactoryBuilder();
        factory = builder.build(reader);
    }
}

6、结果