MyBatis学习总结_09_使用MyBatis Generator自动创建代码

一、构建一个环境

1. 首先创建一个表：

CREATE TABLE
    t_user
    (
        USER_ID INT NOT NULL AUTO_INCREMENT,
        USER_NAME CHAR(30) NOT NULL,
        USER_PASSWORD CHAR(10) NOT NULL,
        USER_EMAIL CHAR(30) NOT NULL,
        PRIMARY KEY (USER_ID)
    )
    ENGINE=InnoDB DEFAULT CHARSET=utf8;

2. 在 Mybatis 主页 http://code.google.com/p/mybatis/ 上下载 Mybatis mybatis-generator-core 或者在这里下载：http://download.csdn.net/detail/evankaka/8926999

二、xml文件编写

1、新建一个工程。然后新建如下包，都是空的

2、然后新建generator.xmll文件

内容如下：

<?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>
    <!-- classPathEntry:数据库的JDBC驱动的jar包地址 -->
    <classPathEntry location="D:JavaJarmysql-connector-java-5.1.22mysql-connector-java-5.1.22-bin.jar" />
    <context id="DB2Tables" targetRuntime="MyBatis3">
        <commentGenerator>
        <!-- 抑制警告 -->
        <property name="suppressTypeWarnings" value="true" />
        <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
        <property name="suppressAllComments" value="false" />
        <!-- 是否生成注释代时间戳-->
        <property name="suppressDate" value="true" />
        </commentGenerator>

        <!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
            connectionURL="jdbc:mysql://localhost/learning" userId="root"
            password="christmas258@">
        </jdbcConnection>
        <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer true，把JDBC DECIMAL 和
            NUMERIC 类型解析为java.math.BigDecimal -->
    <!--     <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver> -->
        <!--生成Model类存放位置 -->
        <javaModelGenerator targetPackage="com.lin.domain"
            targetProject="D:lunaJee-workspaceMyBatisLearningChapter7src">
             <!-- 是否在当前路径下新加一层schema,eg：fase路径com.oop.eksp.user.model， true:com.oop.eksp.user.model.[schemaName] -->
            <property name="enableSubPackages" value="false" />
             <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
            <property name="trimStrings" value="true" />
        </javaModelGenerator>
        <!--生成映射文件存放位置 -->
        <sqlMapGenerator targetPackage="com.lin.mapper"
            targetProject="D:lunaJee-workspaceMyBatisLearningChapter7src">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>
        <!--生成Dao类存放位置 -->
        <javaClientGenerator type="XMLMAPPER"
            targetPackage="com.lin.dao" targetProject="D:lunaJee-workspaceMyBatisLearningChapter7src">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>


        <!-- tableName:用于自动生成代码的数据库表；domainObjectName:对应于数据库表的javaBean类名 -->
        <table schema="general" tableName="T_USER" domainObjectName="User">
         <!--domain字段的命名规则，false:默认为驼峰命名 true:按数据库真实命名  -->
        <property name="useActualColumnNames" value="false"/>
        <!-- 忽略列，不生成bean 字段 -->
        <!--     <ignoreColumn column="FRED" />   -->
        <!-- 指定列的java数据类型 -->
        <!--     <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" />   -->
        </table>
    </context>
</generatorConfiguration>

三、自动代码生成

自动代码生成有4种方法

1、直接cmd下命令行生成

命令如下：Java -jar 电脑上mybatis-generator-core-1.3.0.jar的绝对路径  -configfile 电脑上generator.xml的绝对路径，这里的generator.xml不一定要放在工程的src文件中。

如我的这个项目就是：

运行的结果如下：

然后在eclipse中刷新一下：结果出来了

看看各个文件

（1）User.java

package com.lin.domain;

public class User {
    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column t_user.USER_ID
     *
     * @mbggenerated
     */
    private Integer userId;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column t_user.USER_NAME
     *
     * @mbggenerated
     */
    private String userName;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column t_user.USER_PASSWORD
     *
     * @mbggenerated
     */
    private String userPassword;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column t_user.USER_EMAIL
     *
     * @mbggenerated
     */
    private String userEmail;

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column t_user.USER_ID
     *
     * @return the value of t_user.USER_ID
     *
     * @mbggenerated
     */
    public Integer getUserId() {
        return userId;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column t_user.USER_ID
     *
     * @param userId the value for t_user.USER_ID
     *
     * @mbggenerated
     */
    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column t_user.USER_NAME
     *
     * @return the value of t_user.USER_NAME
     *
     * @mbggenerated
     */
    public String getUserName() {
        return userName;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column t_user.USER_NAME
     *
     * @param userName the value for t_user.USER_NAME
     *
     * @mbggenerated
     */
    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column t_user.USER_PASSWORD
     *
     * @return the value of t_user.USER_PASSWORD
     *
     * @mbggenerated
     */
    public String getUserPassword() {
        return userPassword;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column t_user.USER_PASSWORD
     *
     * @param userPassword the value for t_user.USER_PASSWORD
     *
     * @mbggenerated
     */
    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword == null ? null : userPassword.trim();
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column t_user.USER_EMAIL
     *
     * @return the value of t_user.USER_EMAIL
     *
     * @mbggenerated
     */
    public String getUserEmail() {
        return userEmail;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column t_user.USER_EMAIL
     *
     * @param userEmail the value for t_user.USER_EMAIL
     *
     * @mbggenerated
     */
    public void setUserEmail(String userEmail) {
        this.userEmail = userEmail == null ? null : userEmail.trim();
    }
}

UserExample.java这个文件可以控制是否生成

package com.lin.domain;

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

public class UserExample {
    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database table t_user
     *
     * @mbggenerated
     */
    protected String orderByClause;

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

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

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

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

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

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

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

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

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

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

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

    /**
     * This class was generated by MyBatis Generator.
     * This class corresponds to the database table t_user
     *
     * @mbggenerated
     */
    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> 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 andUserIdIsNull() {
            addCriterion("USER_ID is null");
            return (Criteria) this;
        }

        public Criteria andUserIdIsNotNull() {
            addCriterion("USER_ID is not null");
            return (Criteria) this;
        }

        public Criteria andUserIdEqualTo(Integer value) {
            addCriterion("USER_ID =", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdNotEqualTo(Integer value) {
            addCriterion("USER_ID <>", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdGreaterThan(Integer value) {
            addCriterion("USER_ID >", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdGreaterThanOrEqualTo(Integer value) {
            addCriterion("USER_ID >=", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdLessThan(Integer value) {
            addCriterion("USER_ID <", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdLessThanOrEqualTo(Integer value) {
            addCriterion("USER_ID <=", value, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdIn(List<Integer> values) {
            addCriterion("USER_ID in", values, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdNotIn(List<Integer> values) {
            addCriterion("USER_ID not in", values, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdBetween(Integer value1, Integer value2) {
            addCriterion("USER_ID between", value1, value2, "userId");
            return (Criteria) this;
        }

        public Criteria andUserIdNotBetween(Integer value1, Integer value2) {
            addCriterion("USER_ID not between", value1, value2, "userId");
            return (Criteria) this;
        }

        public Criteria andUserNameIsNull() {
            addCriterion("USER_NAME is null");
            return (Criteria) this;
        }

        public Criteria andUserNameIsNotNull() {
            addCriterion("USER_NAME is not null");
            return (Criteria) this;
        }

        public Criteria andUserNameEqualTo(String value) {
            addCriterion("USER_NAME =", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameNotEqualTo(String value) {
            addCriterion("USER_NAME <>", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameGreaterThan(String value) {
            addCriterion("USER_NAME >", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameGreaterThanOrEqualTo(String value) {
            addCriterion("USER_NAME >=", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameLessThan(String value) {
            addCriterion("USER_NAME <", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameLessThanOrEqualTo(String value) {
            addCriterion("USER_NAME <=", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameLike(String value) {
            addCriterion("USER_NAME like", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameNotLike(String value) {
            addCriterion("USER_NAME not like", value, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameIn(List<String> values) {
            addCriterion("USER_NAME in", values, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameNotIn(List<String> values) {
            addCriterion("USER_NAME not in", values, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameBetween(String value1, String value2) {
            addCriterion("USER_NAME between", value1, value2, "userName");
            return (Criteria) this;
        }

        public Criteria andUserNameNotBetween(String value1, String value2) {
            addCriterion("USER_NAME not between", value1, value2, "userName");
            return (Criteria) this;
        }

        public Criteria andUserPasswordIsNull() {
            addCriterion("USER_PASSWORD is null");
            return (Criteria) this;
        }

        public Criteria andUserPasswordIsNotNull() {
            addCriterion("USER_PASSWORD is not null");
            return (Criteria) this;
        }

        public Criteria andUserPasswordEqualTo(String value) {
            addCriterion("USER_PASSWORD =", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordNotEqualTo(String value) {
            addCriterion("USER_PASSWORD <>", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordGreaterThan(String value) {
            addCriterion("USER_PASSWORD >", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordGreaterThanOrEqualTo(String value) {
            addCriterion("USER_PASSWORD >=", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordLessThan(String value) {
            addCriterion("USER_PASSWORD <", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordLessThanOrEqualTo(String value) {
            addCriterion("USER_PASSWORD <=", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordLike(String value) {
            addCriterion("USER_PASSWORD like", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordNotLike(String value) {
            addCriterion("USER_PASSWORD not like", value, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordIn(List<String> values) {
            addCriterion("USER_PASSWORD in", values, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordNotIn(List<String> values) {
            addCriterion("USER_PASSWORD not in", values, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordBetween(String value1, String value2) {
            addCriterion("USER_PASSWORD between", value1, value2, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserPasswordNotBetween(String value1, String value2) {
            addCriterion("USER_PASSWORD not between", value1, value2, "userPassword");
            return (Criteria) this;
        }

        public Criteria andUserEmailIsNull() {
            addCriterion("USER_EMAIL is null");
            return (Criteria) this;
        }

        public Criteria andUserEmailIsNotNull() {
            addCriterion("USER_EMAIL is not null");
            return (Criteria) this;
        }

        public Criteria andUserEmailEqualTo(String value) {
            addCriterion("USER_EMAIL =", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailNotEqualTo(String value) {
            addCriterion("USER_EMAIL <>", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailGreaterThan(String value) {
            addCriterion("USER_EMAIL >", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailGreaterThanOrEqualTo(String value) {
            addCriterion("USER_EMAIL >=", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailLessThan(String value) {
            addCriterion("USER_EMAIL <", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailLessThanOrEqualTo(String value) {
            addCriterion("USER_EMAIL <=", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailLike(String value) {
            addCriterion("USER_EMAIL like", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailNotLike(String value) {
            addCriterion("USER_EMAIL not like", value, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailIn(List<String> values) {
            addCriterion("USER_EMAIL in", values, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailNotIn(List<String> values) {
            addCriterion("USER_EMAIL not in", values, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailBetween(String value1, String value2) {
            addCriterion("USER_EMAIL between", value1, value2, "userEmail");
            return (Criteria) this;
        }

        public Criteria andUserEmailNotBetween(String value1, String value2) {
            addCriterion("USER_EMAIL not between", value1, value2, "userEmail");
            return (Criteria) this;
        }
    }

    /**
     * This class was generated by MyBatis Generator.
     * This class corresponds to the database table t_user
     *
     * @mbggenerated 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 t_user
     *
     * @mbggenerated
     */
    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;

        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;
        }

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

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

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

（2）dao层文件。它自动取名为UserMapper.java，可以自己手动写成UserDao.java

package com.lin.dao;

import com.lin.domain.User;
import com.lin.domain.UserExample;
import java.util.List;
import org.apache.ibatis.annotations.Param;

public interface UserMapper {
    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int countByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int deleteByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int deleteByPrimaryKey(Integer userId);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int insert(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int insertSelective(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    List<User> selectByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    User selectByPrimaryKey(Integer userId);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int updateByExampleSelective(@Param("record") User record, @Param("example") UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int updateByExample(@Param("record") User record, @Param("example") UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int updateByPrimaryKeySelective(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table t_user
     *
     * @mbggenerated
     */
    int updateByPrimaryKey(User record);
}

(3)Mapper.xml文件：

<?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.lin.dao.UserMapper" >
  <resultMap id="BaseResultMap" type="com.lin.domain.User" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    <id column="USER_ID" property="userId" jdbcType="INTEGER" />
    <result column="USER_NAME" property="userName" jdbcType="CHAR" />
    <result column="USER_PASSWORD" property="userPassword" jdbcType="CHAR" />
    <result column="USER_EMAIL" property="userEmail" jdbcType="CHAR" />
  </resultMap>
  <sql id="Example_Where_Clause" >
    <!--
      WARNING - @mbggenerated
      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="(" 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" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    <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" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    USER_ID, USER_NAME, USER_PASSWORD, USER_EMAIL
  </sql>
  <select id="selectByExample" resultMap="BaseResultMap" parameterType="com.lin.domain.UserExample" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    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" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    select
    <include refid="Base_Column_List" />
    from t_user
    where USER_ID = #{userId,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    delete from t_user
    where USER_ID = #{userId,jdbcType=INTEGER}
  </delete>
  <delete id="deleteByExample" parameterType="com.lin.domain.UserExample" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    delete from t_user
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </delete>
  <insert id="insert" parameterType="com.lin.domain.User" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    insert into t_user (USER_ID, USER_NAME, USER_PASSWORD,
      USER_EMAIL)
    values (#{userId,jdbcType=INTEGER}, #{userName,jdbcType=CHAR}, #{userPassword,jdbcType=CHAR},
      #{userEmail,jdbcType=CHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.lin.domain.User" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    insert into t_user
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="userId != null" >
        USER_ID,
      </if>
      <if test="userName != null" >
        USER_NAME,
      </if>
      <if test="userPassword != null" >
        USER_PASSWORD,
      </if>
      <if test="userEmail != null" >
        USER_EMAIL,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="userId != null" >
        #{userId,jdbcType=INTEGER},
      </if>
      <if test="userName != null" >
        #{userName,jdbcType=CHAR},
      </if>
      <if test="userPassword != null" >
        #{userPassword,jdbcType=CHAR},
      </if>
      <if test="userEmail != null" >
        #{userEmail,jdbcType=CHAR},
      </if>
    </trim>
  </insert>
  <select id="countByExample" parameterType="com.lin.domain.UserExample" resultType="java.lang.Integer" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    select count(*) from t_user
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </select>
  <update id="updateByExampleSelective" parameterType="map" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update t_user
    <set >
      <if test="record.userId != null" >
        USER_ID = #{record.userId,jdbcType=INTEGER},
      </if>
      <if test="record.userName != null" >
        USER_NAME = #{record.userName,jdbcType=CHAR},
      </if>
      <if test="record.userPassword != null" >
        USER_PASSWORD = #{record.userPassword,jdbcType=CHAR},
      </if>
      <if test="record.userEmail != null" >
        USER_EMAIL = #{record.userEmail,jdbcType=CHAR},
      </if>
    </set>
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByExample" parameterType="map" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update t_user
    set USER_ID = #{record.userId,jdbcType=INTEGER},
      USER_NAME = #{record.userName,jdbcType=CHAR},
      USER_PASSWORD = #{record.userPassword,jdbcType=CHAR},
      USER_EMAIL = #{record.userEmail,jdbcType=CHAR}
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByPrimaryKeySelective" parameterType="com.lin.domain.User" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update t_user
    <set >
      <if test="userName != null" >
        USER_NAME = #{userName,jdbcType=CHAR},
      </if>
      <if test="userPassword != null" >
        USER_PASSWORD = #{userPassword,jdbcType=CHAR},
      </if>
      <if test="userEmail != null" >
        USER_EMAIL = #{userEmail,jdbcType=CHAR},
      </if>
    </set>
    where USER_ID = #{userId,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.lin.domain.User" >
    <!--
      WARNING - @mbggenerated
      This element is automatically generated by MyBatis Generator, do not modify.
    -->
    update t_user
    set USER_NAME = #{userName,jdbcType=CHAR},
      USER_PASSWORD = #{userPassword,jdbcType=CHAR},
      USER_EMAIL = #{userEmail,jdbcType=CHAR}
    where USER_ID = #{userId,jdbcType=INTEGER}
  </update>
</mapper>

这样就好了，serivce层的文件自己再去写写就好了。

如果不想要UserExample文件怎么办呢？

那就把

<table schema="general" tableName="T_USER" domainObjectName="User">
 <!--domain字段的命名规则，false:默认为驼峰命名 true:按数据库真实命名  -->
<property name="useActualColumnNames" value="false"/>
</table>

换成：

<table schema="general" tableName="T_USER" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false"
       enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false">
 <!--domain字段的命名规则，false:默认为驼峰命名 true:按数据库真实命名  -->
<property name="useActualColumnNames" value="false"/>
</table>

这样就可以了
2、java代码读取xml文件生成

首先要导入如下的包：

然后在工程里写一个文件如下：

 

package Test;
import java.io.File;
import java.io.IOException;
import java.sql.SQLException;
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.exception.InvalidConfigurationException;
import org.mybatis.generator.exception.XMLParserException;
import org.mybatis.generator.internal.DefaultShellCallback;
public class BuildFile {
    public static void main(String[] args) throws InvalidConfigurationException, IOException, XMLParserException, SQLException, InterruptedException {
        List<String> warnings = new ArrayList<String>();
          boolean overwrite = true;
          File configFile = new File("D:\lunaJee-workspace\MyBatisLearningChapter7\src\generator.xml");  //输入绝对路径
          ConfigurationParser cp = new ConfigurationParser(warnings);
          Configuration config=null;
          config = cp.parseConfiguration(configFile);
          DefaultShellCallback callback = new DefaultShellCallback(overwrite);
          MyBatisGenerator myBatisGenerator = null;
          myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
          myBatisGenerator.generate(null);
    }
}

然后运行，再刷新下就可以了