maven项目重构-使用了mybatis generator插件

1.在worksapce下，dos窗口输入spring init -g=com.briup.apps -a=poll3 -d=mysql,mybatis,web poll3

2.下载依赖，cd到poll3，执行mvn install，会报错，因为没有配置数据库的初始数据

解决方法：eclipse导入poll3，打开/resources/application.properties，输入

spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/pro2.0
spring.datasource.username=root
spring.datasource.password=root
mybatis.mapper-locations= classpath:/mapper/**/*.xml 

mybatis.mapper-locations=classpath:/mapper/**/*.xml  这个配置是为了让dao层找到mapper.xml文件的资源位置，和mapper文件夹下的mapper.xml映射

3.修改pox.xml,内容如下

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.</modelVersion>

    <groupId>com.braup.apps</groupId>
    <artifactId>poll</artifactId>
    <version>0.0.-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0..RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

        <!-- swagger API文档 -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.6.</version>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.6.</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

4.三层架构

5.src/main/resources下新建mapper文件夹，用来保存mapper.xml文件

6.在config包下创建MybatisConfig.java，用来配置mybatis

package com.briup.apps.poll.config;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@MapperScan("com.briup.apps.poll")
public class MybatisConfig {

}

本来应该在DemoApplication.java中配置，已进行标记

package com.braup.apps.poll;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.braup.apps.poll.dao")
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

7.进行测试，mvn spring-boot:run，启动成功表明热部署，三层架构，swagger部署成功

8.编写数据库访问层代码

8.1.手写（时间长，费劲，代码冗余）

8. 2.使用mybatis generator(自动生成bean和dao以及mapper.xml文件)。

mybatis不是框架，是一个插件，不属于项目的一部分，产生的代码是项目的一部分。

8.3配置mabatis generator框架

8.3.1 pom.xml添加依赖

<plugin>
          <groupId>org.mybatis.generator</groupId>
          <artifactId>mybatis-generator-maven-plugin</artifactId>
          <version>1.3.</version>
        </plugin>

8.3.2添加配置文件src/main/resources下添加------------1.根据那些表产生bean. 2.产生的pojo放在哪里. 3.产生的mapper接口放在哪里 4.产生的mapper实现类放在哪里 ........

<?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">
<!-- mybatis-generator的核心配置文件 -->
<generatorConfiguration>
  <classPathEntry location="/Users/lichunyu/springboot/repository/mysql/mysql-connector-java/5.1.45/mysql-connector-java-5.1.45.jar" />

  <context id="DB2Tables" targetRuntime="MyBatis3">
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://127.0.0.1:3306/poll2.0"
        userId="root"
        password="root">
    </jdbcConnection>

    <!--指定生成的类型为java类型，避免数据库中number等类型字段 -->
    <javaTypeResolver >
      <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>

    <!--自动生成的实体的存放包路径 -->
    <javaModelGenerator targetPackage="com.briup.apps.poll.bean" targetProject="./src/main/java">
      <property name="enableSubPackages" value="true" />
      <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!--自动生成的*Mapper.xml文件存放路径 -->
    <sqlMapGenerator targetPackage="mapper"  targetProject="./src/main/resources">
      <property name="enableSubPackages" value="true" />
    </sqlMapGenerator>

    <!--自动生成的*Mapper.java存放路径 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="com.briup.apps.poll.dao"  targetProject="./src/main/java">
      <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 映射配置 -->

    <table tableName="poll_survy" domainObjectName="Survy" ></table>
    <!--
    <table tableName="poll_school" domainObjectName="School" ></table>
    <table tableName="poll_grade" domainObjectName="Grade" ></table>
    <table tableName="poll_clazz" domainObjectName="Clazz" ></table>
    <table tableName="poll_course" domainObjectName="Course" ></table>
    <table tableName="poll_grade_course" domainObjectName="GradeCourse" ></table>
    <table tableName="poll_user" domainObjectName="User" ></table>
    <table tableName="poll_option" domainObjectName="Option" ></table>
    <table tableName="poll_question" domainObjectName="Question" ></table>
    <table tableName="poll_questionnaire" domainObjectName="Questionnaire" ></table>
    <table tableName="poll_questionnaire_question" domainObjectName="QuestionnaireQuestion" ></table>
    -->
  </context>
</generatorConfiguration>

8.3.3开始工作-( 要关闭项目)

mvn -Dmybatis.generator.overwrite=true mybatis-generator:generate