mybati逆向工程

MyBatis Generator Core:MyBatis生成器- MyBatis的代码生成器。

             下载地址https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core

Mybatis Generator是一个用于Mybatis逆向工程的工具。我以前都是先有pojo, mapper, xml, 然后再创建表。
用逆向工程的方式，首先保证数据库里有表，然后通过Mybatis Generator生成pojo, mapper和xml。
可以节约大家的时间，提高开发效率，降低出错几率

mybatis-generator-core-1.3.5.jar

 

 1.新建java项目,新建lib,导入库,

2.新建mybatis的配置文件: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>
    <typeAliases>
        <package name="com.how2java.pojo"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/how2java/pojo/CategoryMapper.xml"/>
        <!--<mapper resource="com/how2java/pojo/ProductMapper.xml"/>-->
    </mappers>
</configuration>

3.新建mybatis逆向工程的配置文件:generatorConfig.xml

这个配置文件有如下作用
1. 指定 mysql jdbcjar 包的位置,这里用的位置是 D:\java-spring学习\mybatis23\lib/mysql-connector-java-5.0.8-bin.jar
2. 设置数据库链接账号密码
3. 指定pojo,mapper,xml分别生成的包名
4. 指定表名以及表名对应的类名
4.1 使用自增长键：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!--数据库驱动-->
    <!--
        如果IDE(eclipse或者idea) 项目里导入了jar包，那么就不需要配置了jar包的绝对路径了
         <classPathEntry    location="D:\java-spring学习\mybatis23\lib/mysql-connector-java-5.0.8-bin.jar"/>
    -->
    <context id="DB2Tables"    targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <property name="suppressAllComments" value="false"/>
        </commentGenerator>
        <!--数据库链接地址账号密码-->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://localhost/mybatis" userId="root" password="root">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!--生成Model类存放位置-->
        <javaModelGenerator targetPackage="com.how2java.pojo" targetProject="src">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!--生成映射文件存放位置-->
        <sqlMapGenerator targetPackage="com.how2java.pojo" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!--生成Dao类存放位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.how2java.mapper" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!--生成对应表及类名-->
        <table tableName="category_" domainObjectName="Category" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="true" selectByExampleQueryId="false">
            <property name="my.isgen.usekeys" value="true"/>
            <generatedKey column="id" sqlStatement="JDBC"/>
        </table>
        <!--         <table tableName="product_" domainObjectName="Product" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table> -->
    </context>
</generatorConfiguration>

 

4.测试Mybatis生成器:TestMybatisGenerator

package com.how2java;

import java.io.File;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;

/**
 * 测试Mybatis生成器
 * 运行成功之后，就会在对应位置生成pojo,xml,和mapper
 * @author lenovo
 */
public class TestMybatisGenerator {

    public static void main(String[] args) throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        InputStream is= TestMybatisGenerator.class.getClassLoader().getResource("generatorConfig.xml").openStream();
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(is);
        is.close();
        DefaultShellCallback callback = new DefaultShellCallback(true);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
        System.out.println("生成代码成功，刷新项目，查看文件,然后执行TestMybatis.java");

    }
}

5.新建MybatisTest类

import java.io.InputStream;
import java.util.List;

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

import com.how2java.mapper.CategoryMapper;
import com.how2java.pojo.Category;
import com.how2java.pojo.CategoryExample;

/**
 * 执行自动生成的mapper，借助CategoryExample 进行模糊查询名称里出现了9的分类
 * @author lenovo
 */
public class MybatisTest {
    public static void main(String args[]) throws Exception {
        System.out.println("先运行TestMybatisGenerator创建mapper,pojo,xml 等文件，然后取消import里被注释的，以及接下来的注释，并执行代码");

//
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session=sqlSessionFactory.openSession();

        CategoryExample example = new CategoryExample();
        example.createCriteria().andNameLike("%9%");
        CategoryMapper mapper = session.getMapper(CategoryMapper.class);
        List<Category> cs= mapper.selectByExample(example);

        for (Category c : cs) {
            System.out.println(c.getName());
        }

    }
}

结果:

先运行TestMybatisGenerator创建mapper,pojo,xml 等文件，然后取消import里被注释的，以及接下来的注释，并执行代码
category name 99
category name 98
category name 97
category name 96
category name 95
category name 94
category name 93
category name 92
category name 91
category name 90
category name 89
category name 79
category name 69
category name 59
category name 49
category name 39
category name 29
category name 19
category name 9

 

逆向工程自动生成的文件:

package com.how2java.mapper;

import com.how2java.pojo.Category;
import com.how2java.pojo.CategoryExample;
import java.util.List;

public interface CategoryMapper {
    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    int deleteByPrimaryKey(Integer id);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    int insert(Category record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    int insertSelective(Category record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    List<Category> selectByExample(CategoryExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    Category selectByPrimaryKey(Integer id);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    int updateByPrimaryKeySelective(Category record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    int updateByPrimaryKey(Category record);
}

package com.how2java.pojo;

public class Category {
    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column category_.id
     *
     * @mbg.generated
     */
    private Integer id;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column category_.name
     *
     * @mbg.generated
     */
    private String name;

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column category_.id
     *
     * @return the value of category_.id
     *
     * @mbg.generated
     */
    public Integer getId() {
        return id;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column category_.id
     *
     * @param id the value for category_.id
     *
     * @mbg.generated
     */
    public void setId(Integer id) {
        this.id = id;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column category_.name
     *
     * @return the value of category_.name
     *
     * @mbg.generated
     */
    public String getName() {
        return name;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column category_.name
     *
     * @param name the value for category_.name
     *
     * @mbg.generated
     */
    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }
}

 

package com.how2java.pojo;

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

public class CategoryExample {
    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database table category_
     *
     * @mbg.generated
     */
    protected String orderByClause;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database table category_
     *
     * @mbg.generated
     */
    protected boolean distinct;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database table category_
     *
     * @mbg.generated
     */
    protected List<Criteria> oredCriteria;

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public CategoryExample() {
        oredCriteria = new ArrayList<Criteria>();
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public void setOrderByClause(String orderByClause) {
        this.orderByClause = orderByClause;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public String getOrderByClause() {
        return orderByClause;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public void setDistinct(boolean distinct) {
        this.distinct = distinct;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public boolean isDistinct() {
        return distinct;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public List<Criteria> getOredCriteria() {
        return oredCriteria;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public void or(Criteria criteria) {
        oredCriteria.add(criteria);
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public Criteria or() {
        Criteria criteria = createCriteriaInternal();
        oredCriteria.add(criteria);
        return criteria;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public Criteria createCriteria() {
        Criteria criteria = createCriteriaInternal();
        if (oredCriteria.size() == 0) {
            oredCriteria.add(criteria);
        }
        return criteria;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    protected Criteria createCriteriaInternal() {
        Criteria criteria = new Criteria();
        return criteria;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table category_
     *
     * @mbg.generated
     */
    public void clear() {
        oredCriteria.clear();
        orderByClause = null;
        distinct = false;
    }

    /**
     * This class was generated by MyBatis Generator.
     * This class corresponds to the database table category_
     *
     * @mbg.generated
     */
    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 andNameIsNull() {
            addCriterion("name is null");
            return (Criteria) this;
        }

        public Criteria andNameIsNotNull() {
            addCriterion("name is not null");
            return (Criteria) this;
        }

        public Criteria andNameEqualTo(String value) {
            addCriterion("name =", value, "name");
            return (Criteria) this;
        }

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

        public Criteria andNameGreaterThan(String value) {
            addCriterion("name >", value, "name");
            return (Criteria) this;
        }

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

        public Criteria andNameLessThan(String value) {
            addCriterion("name <", value, "name");
            return (Criteria) this;
        }

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

        public Criteria andNameLike(String value) {
            addCriterion("name like", value, "name");
            return (Criteria) this;
        }

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

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

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

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

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

    /**
     * This class was generated by MyBatis Generator.
     * This class corresponds to the database table category_
     *
     * @mbg.generated do_not_delete_during_merge
     */
    public static class Criteria extends GeneratedCriteria {

        protected Criteria() {
            super();
        }
    }

    /**
     * This class was generated by MyBatis Generator.
     * This class corresponds to the database table category_
     *
     * @mbg.generated
     */
    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);
        }
    }
}

 

<?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.how2java.mapper.CategoryMapper">
  <resultMap id="BaseResultMap" type="com.how2java.pojo.Category">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
  </resultMap>
  <sql id="Example_Where_Clause">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    <where>
      <foreach collection="oredCriteria" item="criteria" separator="or">
        <if test="criteria.valid">
          <trim prefix="(" prefixOverrides="and" suffix=")">
            <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 close=")" collection="criterion.value" item="listItem" open="(" separator=",">
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Base_Column_List">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    id, name
  </sql>
  <select id="selectByExample" parameterType="com.how2java.pojo.CategoryExample" resultMap="BaseResultMap">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    select
    <if test="distinct">
      distinct
    </if>
    'false' as QUERYID,
    <include refid="Base_Column_List" />
    from category_
    <if test="_parameter != null">
      <include refid="Example_Where_Clause" />
    </if>
    <if test="orderByClause != null">
      order by ${orderByClause}
    </if>
  </select>
  <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    select 
    <include refid="Base_Column_List" />
    from category_
    where id = #{id,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    delete from category_
    where id = #{id,jdbcType=INTEGER}
  </delete>
  <insert id="insert" keyColumn="id" keyProperty="id" parameterType="com.how2java.pojo.Category" useGeneratedKeys="true">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    insert into category_ (name)
    values (#{name,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" keyColumn="id" keyProperty="id" parameterType="com.how2java.pojo.Category" useGeneratedKeys="true">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    insert into category_
    <trim prefix="(" suffix=")" suffixOverrides=",">
      <if test="name != null">
        name,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides=",">
      <if test="name != null">
        #{name,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.how2java.pojo.Category">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update category_
    <set>
      <if test="name != null">
        name = #{name,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.how2java.pojo.Category">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update category_
    set name = #{name,jdbcType=VARCHAR}
    where id = #{id,jdbcType=INTEGER}
  </update>
</mapper>

 

局限性:需要自己写,一对多,多对一,这个工具目前(mybatis-generator-core-1.3.5.jar)不提供