您的位置: 首页  >  文章  >  MyBatis使用分页插件

MyBatis使用分页插件

分类: 文章 • 2022-10-16 22:56:15

网址

github-中文文档

https://github.com/pagehelper/Mybatis-PageHelper/blob/master/README_zh.md

MyBatis使用分页插件

github-英文文档

https://github.com/pagehelper/Mybatis-PageHelper

使用方法

https://github.com/pagehelper/Mybatis-PageHelper/blob/master/wikis/zh/HowToUse.md

MyBatis使用分页插件

api

https://apidoc.gitee.com/free/Mybatis_PageHelper/overview-summary.html

MyBatis使用分页插件

工程

目录结构

MyBatis使用分页插件

工程框架

MyBatis使用分页插件

jar包

MyBatis使用分页插件

entity.User.java

package entity;

public class User {

    private Integer id;

    private String username;

    private String password;

    private String phone;

    private String address;

    public User() {
    }

    public User(String username, String password, String phone, String address) {
        this.username = username;
        this.password = password;
        this.phone = phone;
        this.address = address;
    }

    public User(Integer id, String username, String password, String phone, String address) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.phone = phone;
        this.address = address;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username == null ? null : username.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone == null ? null : phone.trim();
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address == null ? null : address.trim();
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", phone='" + phone + '\'' +
                ", address='" + address + '\'' +
                "}\n";
    }
}

entity.UserExample

package entity;

import java.util.ArrayList;
import java.util.List;

public class UserExample {

    protected String orderByClause;

    protected boolean distinct;

    protected List<Criteria> oredCriteria;

    public UserExample() {
        oredCriteria = new ArrayList<Criteria>();
    }

    public void setOrderByClause(String orderByClause) {
        this.orderByClause = orderByClause;
    }

    public String getOrderByClause() {
        return orderByClause;
    }

    public void setDistinct(boolean distinct) {
        this.distinct = distinct;
    }

    public boolean isDistinct() {
        return distinct;
    }

    public List<Criteria> getOredCriteria() {
        return oredCriteria;
    }

    public void or(Criteria criteria) {
        oredCriteria.add(criteria);
    }

    public Criteria or() {
        Criteria criteria = createCriteriaInternal();
        oredCriteria.add(criteria);
        return criteria;
    }

    public Criteria createCriteria() {
        Criteria criteria = createCriteriaInternal();
        if (oredCriteria.size() == 0) {
            oredCriteria.add(criteria);
        }
        return criteria;
    }

    protected Criteria createCriteriaInternal() {
        Criteria criteria = new Criteria();
        return criteria;
    }

    public void clear() {
        oredCriteria.clear();
        orderByClause = null;
        distinct = false;
    }

    protected abstract static class GeneratedCriteria {
        protected List<Criterion> criteria;

        protected GeneratedCriteria() {
            super();
            criteria = new ArrayList<Criterion>();
        }

        public boolean isValid() {
            return criteria.size() > 0;
        }

        public List<Criterion> getAllCriteria() {
            return criteria;
        }

        public List<Criterion> getCriteria() {
            return criteria;
        }

        protected void addCriterion(String condition) {
            if (condition == null) {
                throw new RuntimeException("Value for condition cannot be null");
            }
            criteria.add(new Criterion(condition));
        }

        protected void addCriterion(String condition, Object value, String property) {
            if (value == null) {
                throw new RuntimeException("Value for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value));
        }

        protected void addCriterion(String condition, Object value1, Object value2, String property) {
            if (value1 == null || value2 == null) {
                throw new RuntimeException("Between values for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value1, value2));
        }

        public Criteria andIdIsNull() {
            addCriterion("id is null");
            return (Criteria) this;
        }

        public Criteria andIdIsNotNull() {
            addCriterion("id is not null");
            return (Criteria) this;
        }

        public Criteria andIdEqualTo(Integer value) {
            addCriterion("id =", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotEqualTo(Integer value) {
            addCriterion("id <>", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdGreaterThan(Integer value) {
            addCriterion("id >", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdGreaterThanOrEqualTo(Integer value) {
            addCriterion("id >=", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdLessThan(Integer value) {
            addCriterion("id <", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdLessThanOrEqualTo(Integer value) {
            addCriterion("id <=", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdIn(List<Integer> values) {
            addCriterion("id in", values, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotIn(List<Integer> values) {
            addCriterion("id not in", values, "id");
            return (Criteria) this;
        }

        public Criteria andIdBetween(Integer value1, Integer value2) {
            addCriterion("id between", value1, value2, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotBetween(Integer value1, Integer value2) {
            addCriterion("id not between", value1, value2, "id");
            return (Criteria) this;
        }

        public Criteria andUsernameIsNull() {
            addCriterion("username is null");
            return (Criteria) this;
        }

        public Criteria andUsernameIsNotNull() {
            addCriterion("username is not null");
            return (Criteria) this;
        }

        public Criteria andUsernameEqualTo(String value) {
            addCriterion("username =", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameNotEqualTo(String value) {
            addCriterion("username <>", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameGreaterThan(String value) {
            addCriterion("username >", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameGreaterThanOrEqualTo(String value) {
            addCriterion("username >=", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameLessThan(String value) {
            addCriterion("username <", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameLessThanOrEqualTo(String value) {
            addCriterion("username <=", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameLike(String value) {
            addCriterion("username like", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameNotLike(String value) {
            addCriterion("username not like", value, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameIn(List<String> values) {
            addCriterion("username in", values, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameNotIn(List<String> values) {
            addCriterion("username not in", values, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameBetween(String value1, String value2) {
            addCriterion("username between", value1, value2, "username");
            return (Criteria) this;
        }

        public Criteria andUsernameNotBetween(String value1, String value2) {
            addCriterion("username not between", value1, value2, "username");
            return (Criteria) this;
        }

        public Criteria andPasswordIsNull() {
            addCriterion("password is null");
            return (Criteria) this;
        }

        public Criteria andPasswordIsNotNull() {
            addCriterion("password is not null");
            return (Criteria) this;
        }

        public Criteria andPasswordEqualTo(String value) {
            addCriterion("password =", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordNotEqualTo(String value) {
            addCriterion("password <>", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordGreaterThan(String value) {
            addCriterion("password >", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordGreaterThanOrEqualTo(String value) {
            addCriterion("password >=", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordLessThan(String value) {
            addCriterion("password <", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordLessThanOrEqualTo(String value) {
            addCriterion("password <=", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordLike(String value) {
            addCriterion("password like", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordNotLike(String value) {
            addCriterion("password not like", value, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordIn(List<String> values) {
            addCriterion("password in", values, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordNotIn(List<String> values) {
            addCriterion("password not in", values, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordBetween(String value1, String value2) {
            addCriterion("password between", value1, value2, "password");
            return (Criteria) this;
        }

        public Criteria andPasswordNotBetween(String value1, String value2) {
            addCriterion("password not between", value1, value2, "password");
            return (Criteria) this;
        }

        public Criteria andPhoneIsNull() {
            addCriterion("phone is null");
            return (Criteria) this;
        }

        public Criteria andPhoneIsNotNull() {
            addCriterion("phone is not null");
            return (Criteria) this;
        }

        public Criteria andPhoneEqualTo(String value) {
            addCriterion("phone =", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneNotEqualTo(String value) {
            addCriterion("phone <>", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneGreaterThan(String value) {
            addCriterion("phone >", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneGreaterThanOrEqualTo(String value) {
            addCriterion("phone >=", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneLessThan(String value) {
            addCriterion("phone <", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneLessThanOrEqualTo(String value) {
            addCriterion("phone <=", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneLike(String value) {
            addCriterion("phone like", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneNotLike(String value) {
            addCriterion("phone not like", value, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneIn(List<String> values) {
            addCriterion("phone in", values, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneNotIn(List<String> values) {
            addCriterion("phone not in", values, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneBetween(String value1, String value2) {
            addCriterion("phone between", value1, value2, "phone");
            return (Criteria) this;
        }

        public Criteria andPhoneNotBetween(String value1, String value2) {
            addCriterion("phone not between", value1, value2, "phone");
            return (Criteria) this;
        }

        public Criteria andAddressIsNull() {
            addCriterion("address is null");
            return (Criteria) this;
        }

        public Criteria andAddressIsNotNull() {
            addCriterion("address is not null");
            return (Criteria) this;
        }

        public Criteria andAddressEqualTo(String value) {
            addCriterion("address =", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressNotEqualTo(String value) {
            addCriterion("address <>", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressGreaterThan(String value) {
            addCriterion("address >", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressGreaterThanOrEqualTo(String value) {
            addCriterion("address >=", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressLessThan(String value) {
            addCriterion("address <", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressLessThanOrEqualTo(String value) {
            addCriterion("address <=", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressLike(String value) {
            addCriterion("address like", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressNotLike(String value) {
            addCriterion("address not like", value, "address");
            return (Criteria) this;
        }

        public Criteria andAddressIn(List<String> values) {
            addCriterion("address in", values, "address");
            return (Criteria) this;
        }

        public Criteria andAddressNotIn(List<String> values) {
            addCriterion("address not in", values, "address");
            return (Criteria) this;
        }

        public Criteria andAddressBetween(String value1, String value2) {
            addCriterion("address between", value1, value2, "address");
            return (Criteria) this;
        }

        public Criteria andAddressNotBetween(String value1, String value2) {
            addCriterion("address not between", value1, value2, "address");
            return (Criteria) this;
        }
    }

    public static class Criteria extends GeneratedCriteria {

        protected Criteria() {
            super();
        }
    }

    public static class Criterion {
        private String condition;

        private Object value;

        private Object secondValue;

        private boolean noValue;

        private boolean singleValue;

        private boolean betweenValue;

        private boolean listValue;

        private String typeHandler;

        public String getCondition() {
            return condition;
        }

        public Object getValue() {
            return value;
        }

        public Object getSecondValue() {
            return secondValue;
        }

        public boolean isNoValue() {
            return noValue;
        }

        public boolean isSingleValue() {
            return singleValue;
        }

        public boolean isBetweenValue() {
            return betweenValue;
        }

        public boolean isListValue() {
            return listValue;
        }

        public String getTypeHandler() {
            return typeHandler;
        }

        protected Criterion(String condition) {
            super();
            this.condition = condition;
            this.typeHandler = null;
            this.noValue = true;
        }

        protected Criterion(String condition, Object value, String typeHandler) {
            super();
            this.condition = condition;
            this.value = value;
            this.typeHandler = typeHandler;
            if (value instanceof List<?>) {
                this.listValue = true;
            } else {
                this.singleValue = true;
            }
        }

        protected Criterion(String condition, Object value) {
            this(condition, value, null);
        }

        protected Criterion(String condition, Object value, Object secondValue, String typeHandler) {
            super();
            this.condition = condition;
            this.value = value;
            this.secondValue = secondValue;
            this.typeHandler = typeHandler;
            this.betweenValue = true;
        }

        protected Criterion(String condition, Object value, Object secondValue) {
            this(condition, value, secondValue, null);
        }
    }
}

dao.UserMapper.java

package dao;

import entity.User;
import entity.UserExample;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface UserMapper {

    int countByExample(UserExample example);

    int deleteByExample(UserExample example);

    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    List<User> selectByExample(UserExample example);

    User selectByPrimaryKey(Integer id);

    int updateByExampleSelective(@Param("record") User record, @Param("example") UserExample example);

    int updateByExample(@Param("record") User record, @Param("example") UserExample example);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
}

mapper.Usermapper.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="dao.UserMapper" >
  <resultMap id="BaseResultMap" type="entity.User" >
   
    <id column="id" property="id" jdbcType="INTEGER" />
    <result column="username" property="username" jdbcType="VARCHAR" />
    <result column="password" property="password" jdbcType="VARCHAR" />
    <result column="phone" property="phone" jdbcType="VARCHAR" />
    <result column="address" property="address" jdbcType="VARCHAR" />
  </resultMap>
  <sql id="Example_Where_Clause" >
   
    <where >
      <foreach collection="oredCriteria" item="criteria" separator="or" >
        <if test="criteria.valid" >
          <trim prefix="(" suffix=")" prefixOverrides="and" >
            <foreach collection="criteria.criteria" item="criterion" >
              <choose >
                <when test="criterion.noValue" >
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue" >
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue" >
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue" >
                  and ${criterion.condition}
                  <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Update_By_Example_Where_Clause" >
   
    <where >
      <foreach collection="example.oredCriteria" item="criteria" separator="or" >
        <if test="criteria.valid" >
          <trim prefix="(" suffix=")" prefixOverrides="and" >
            <foreach collection="criteria.criteria" item="criterion" >
              <choose >
                <when test="criterion.noValue" >
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue" >
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue" >
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue" >
                  and ${criterion.condition}
                  <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Base_Column_List" >
   
    id, username, password, phone, address
  </sql>
  <select id="selectByExample" resultMap="BaseResultMap" parameterType="entity.UserExample" >
   
    select
    <if test="distinct" >
      distinct
    </if>
    <include refid="Base_Column_List" />
    from t_user
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
    <if test="orderByClause != null" >
      order by ${orderByClause}
    </if>
  </select>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
   
    select
    <include refid="Base_Column_List" />
    from t_user
    where id = #{id,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
   
    delete from t_user
    where id = #{id,jdbcType=INTEGER}
  </delete>
  <delete id="deleteByExample" parameterType="entity.UserExample" >
   
    delete from t_user
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </delete>
  <insert id="insert" parameterType="entity.User" useGeneratedKeys="true" keyProperty="id">
   
    insert into t_user (id, username, password,
      phone, address)
    values (#{id,jdbcType=INTEGER}, #{username,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},
      #{phone,jdbcType=VARCHAR}, #{address,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="entity.User"  useGeneratedKeys="true" keyProperty="id">
   
    insert into t_user
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        id,
      </if>
      <if test="username != null" >
        username,
      </if>
      <if test="password != null" >
        password,
      </if>
      <if test="phone != null" >
        phone,
      </if>
      <if test="address != null" >
        address,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        #{id,jdbcType=INTEGER},
      </if>
      <if test="username != null" >
        #{username,jdbcType=VARCHAR},
      </if>
      <if test="password != null" >
        #{password,jdbcType=VARCHAR},
      </if>
      <if test="phone != null" >
        #{phone,jdbcType=VARCHAR},
      </if>
      <if test="address != null" >
        #{address,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <select id="countByExample" parameterType="entity.UserExample" resultType="java.lang.Integer" >
   
    select count(*) from t_user
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </select>
  <update id="updateByExampleSelective" parameterType="map" >
   
    update t_user
    <set >
      <if test="record.id != null" >
        id = #{record.id,jdbcType=INTEGER},
      </if>
      <if test="record.username != null" >
        username = #{record.username,jdbcType=VARCHAR},
      </if>
      <if test="record.password != null" >
        password = #{record.password,jdbcType=VARCHAR},
      </if>
      <if test="record.phone != null" >
        phone = #{record.phone,jdbcType=VARCHAR},
      </if>
      <if test="record.address != null" >
        address = #{record.address,jdbcType=VARCHAR},
      </if>
    </set>
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByExample" parameterType="map" >
   
    update t_user
    set id = #{record.id,jdbcType=INTEGER},
      username = #{record.username,jdbcType=VARCHAR},
      password = #{record.password,jdbcType=VARCHAR},
      phone = #{record.phone,jdbcType=VARCHAR},
      address = #{record.address,jdbcType=VARCHAR}
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByPrimaryKeySelective" parameterType="entity.User" >
   
    update t_user
    <set >
      <if test="username != null" >
        username = #{username,jdbcType=VARCHAR},
      </if>
      <if test="password != null" >
        password = #{password,jdbcType=VARCHAR},
      </if>
      <if test="phone != null" >
        phone = #{phone,jdbcType=VARCHAR},
      </if>
      <if test="address != null" >
        address = #{address,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="entity.User" >
   
    update t_user
    set username = #{username,jdbcType=VARCHAR},
      password = #{password,jdbcType=VARCHAR},
      phone = #{phone,jdbcType=VARCHAR},
      address = #{address,jdbcType=VARCHAR}
    where id = #{id,jdbcType=INTEGER}
  </update>
</mapper>

dataSource.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&serverTimezone=UTC&charaterEncoding=utf-8
jdbc.username=root
jdbc.password=graspaa

log4j.properties

log4j.rootLogger=debug,console
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%-5p %m%n

log4j.logger.java.sql.ResultSet=INFO
log4j.logger.org.apache=INFO
log4j.logger.java.sql.PreparedStatement=DEBUG

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <properties resource="dataSource.properties"/>

    <typeAliases>
        <package name="entity"/>
    </typeAliases>

    <plugins>
        <!-- 配置分页插件 -->
        <!-- com.github.pagehelper为PageHelper类所在包名，如果没有导入jar包，就会报MyBatisUtil.java的错 -->
        <plugin interceptor="com.github.pagehelper.PageHelper">
        </plugin>
    </plugins>
   
    <environments default="hello">
        <environment id="hello">
            <transactionManager type="jdbc"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="mapper/UserMapper.xml"/>
    </mappers>
</configuration>

util.MyBatisUtil.java

package util;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

/**
 * Author: xian
 * Date: 2020-06-19 13:40
 * description:
 */
public class MyBatisUtil {
    public static SqlSessionFactory sqlSessionFactory;
    private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<>();

    static {
        try {
            sqlSessionFactory = new SqlSessionFactoryBuilder()
                    .build(MyBatisUtil.class.getClassLoader().getResourceAsStream("mybatis-config.xml"));
        } catch (Exception e) {
            throw new ExceptionInInitializerError("MyBatisUtil初始化失败：" + e.getMessage());
        }
    }

    public static SqlSession getSession() {
        SqlSession sqlSession = threadLocal.get();
        if (sqlSession == null) {
            sqlSession = sqlSessionFactory.openSession();
            threadLocal.set(sqlSession);
        }
        return sqlSession;
    }

    public static void close() {
        SqlSession sqlSession = threadLocal.get();
        if (sqlSession != null) {
            sqlSession.close();
            threadLocal.remove();
        }
    }
}

test.Test

package test;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import dao.UserMapper;
import entity.User;
import entity.UserExample;
import org.apache.ibatis.session.SqlSession;
import util.MyBatisUtil;

import java.util.List;

/**
 * Author: xian
 * Date: 2020-06-22 10:20
 * description:
 */
public class Test {
    public static void main(String[] args) {
        SqlSession session = null;
        try {
            session = MyBatisUtil.getSession();

            UserMapper userMapper = session.getMapper(UserMapper.class);

            //String temp = "j";
            //User user = new User(8, temp, temp, null, temp);
            //User user1 = userMapper.selectByPrimaryKey(7);

            //UserExample userExample = new UserExample();
            //userExample.or().andUsernameEqualTo("e")
            //                .andPasswordEqualTo("e");
            //
            //userExample.or().andAddressEqualTo("c");
            //List<User> users = userMapper.selectByExample(userExample);
            //System.out.println(users);

            int pageNum = 2;
            int pageSize = 4;
            PageHelper.startPage(pageNum, pageSize);

            List<User> users = userMapper.selectByExample(new UserExample());
            PageInfo<User> userPageInfo = new PageInfo<>(users);
            System.out.println(userPageInfo);
            System.out.println("\n");

            int pageNum1 = userPageInfo.getPageNum();
            int pageSize1 = userPageInfo.getPageSize();
            int pages = userPageInfo.getPages();
            long total = userPageInfo.getTotal();
            System.out.println("第几页："+pageNum1);
            System.out.println("页大小："+pageSize1);
            System.out.println("总页数："+pages);
            System.out.println("数据总共有几条："+total);

            System.out.println("\n");
            for (User user : users) {
                System.out.println(user);
            }
            //System.out.println(users);

            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        } finally {
            MyBatisUtil.close();
        }
    }
}

运行

MyBatis使用分页插件

源码

https://gitee.com/xian1990/mybatis/tree/noob

相关推荐