MyBatis逆向工程

简介

是一个专门为MyBatis框架使用者定制的代码生成器，可以快速的根据表生成对应的映射文件，接口，以及bean类。支持基本的增删改查，以及QBC风格的条件查询。
官方文档地址
http://www.mybatis.org/generator/
官方工程地址
https://github.com/mybatis/generator/releases

配置

1. 导入逆向工程的jar包
   mybatis-generator-core-1.3.2.jar
2. 编写MBG的配置文件

<?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>



? <context id="DB2Tables" targetRuntime="MyBatis3">

?????<!-- 设置连接数据库的信息 -->

??? <jdbcConnection driverClass="com.mysql.jdbc.Driver"

??????? 
connectionURL="jdbc:mysql://localhost:3306/mybatis"

??????? userId="root"

??????? password="liushuai">

??? </jdbcConnection>



??? <javaTypeResolver >

????? <property name="forceBigDecimals" value="false" />

??? </javaTypeResolver>



?????<!-- <u>javabean</u>的生成策略 -->

??? <javaModelGenerator targetPackage="com.atguigu.bean" 
targetProject=".\src">

????? <property name="enableSubPackages" value="true" />

????? <property name="trimStrings" value="true" />

??? </javaModelGenerator>





?????<!-- 映射文件的生成策略 -->

??? <sqlMapGenerator targetPackage="com.atguigu.mapper"? 
targetProject=".\conf">

????? <property name="enableSubPackages" value="true" />

??? </sqlMapGenerator>



?????<!-- <u>mapper</u>接口的生成策略 -->

??? <javaClientGenerator type="XMLMAPPER" 
targetPackage="com.atguigu.mapper"? 
targetProject=".\src">

????? <property name="enableSubPackages" value="true" />

??? </javaClientGenerator>



?????<!-- 设置要将数据库中的哪张表逆向生成哪一个<u>javabean</u> 
-->

?????<table tableName="emp" 
domainObjectName="Emp"></table>

?????<table tableName="dept" 
domainObjectName="Dept"></table>



? </context>

</generatorConfiguration>

3. 运行代码生成器生成代码

@Test

?????public void testMBG() throws Exception {

??????? List<String> warnings = new ArrayList<String>();

??????? boolean overwrite = true;

??????? File configFile = new File("mbg.xml");

??????? ConfigurationParser cp = new 
ConfigurationParser(warnings);

??????? Configuration config = 
cp.parseConfiguration(configFile);

??????? DefaultShellCallback callback = new 
DefaultShellCallback(overwrite);

??????? MyBatisGenerator myBatisGenerator = new 
MyBatisGenerator(config, callback, warnings);

??????? myBatisGenerator.generate(null);

?????}

应用

要注意数据库中的表与mbg.xml中设置的相同，得到如下mapper和bean文件

扩展-PageHelper分页插件

使用步骤

1. 导入相关包pagehelper-x.x.x.jar 和 jsqlparser-0.9.5.jar

2. 在MyBatis全局配置文件中配置分页插件

<!-- 分页插件设置 -->

?????<plugins>

??????????<plugin 
interceptor="com.github.pagehelper.PageInterceptor"></plugin>

?????</plugins>

3. 建立一个util工具类

public class PageUtil {



?????public static String getPageInfo(PageInfo<Emp> 
pageInfo, HttpServletRequest request) {

??????????

??????????String path = request.getContextPath() + "/";

??????????StringBuilder builder = new StringBuilder();

??????????

??????????//拼接首页

??????????builder.append("<a href=‘"+path+"emps/1‘>首页</a>");

??????????builder.append("&nbsp;&nbsp;");

??????????

??????????//拼接上一页

??????????if(pageInfo.isHasPreviousPage()) {

??????????????builder.append("<a 
href=‘"+path+"emps/"+pageInfo.getPrePage()+"‘>上一页</a>");

??????????????builder.append("&nbsp;&nbsp;");

??????????}else {

??????????????builder.append("上一页");

??????????????builder.append("&nbsp;&nbsp;");

??????????}

??????????

??????????//拼接页码

??????????int[] nums = pageInfo.getNavigatepageNums();

??????????for (int i : nums) {

??????????????if(i == pageInfo.getPageNum()) {

???????????????????builder.append("<a style=‘color:red;‘ 
href=‘"+path+"emps/"+i+"‘>"+i+"</a>");

???????????????????builder.append("&nbsp;&nbsp;");

??????????????}else {

???????????????????builder.append("<a 
href=‘"+path+"emps/"+i+"‘>"+i+"</a>");

???????????????????builder.append("&nbsp;&nbsp;");

??????????????}

??????????}

??????????

??????????//拼接下一页

??????????if(pageInfo.isHasNextPage()) {

??????????????builder.append("<a 
href=‘"+path+"emps/"+pageInfo.getNextPage()+"‘>下一页</a>");

??????????????builder.append("&nbsp;&nbsp;");

??????????}else {

??????????????builder.append("下一页");

??????????????builder.append("&nbsp;&nbsp;");

??????????}

??????????

??????????//拼接尾页

??????????builder.append("<a 
href=‘"+path+"emps/"+pageInfo.getPages()+"‘>尾页</a>");

??????????builder.append("&nbsp;&nbsp;");

??????????

??????????return builder.toString()；
?????}
}

4. 使用PageHelper提供的方法进行分页， 可以使用更强大的PageInfo封装返回结果

@RequestMapping(value = "/emps/{pageNum}", method = 
RequestMethod.GET)

?????public String getAllEmp(Map<String, Object> 
map,@PathVariable("pageNum") Integer pageNum, 
HttpServletRequest request) {

??????????//使用分页插件

??????? //传入查询的页码，以及显示的条数

??????????PageHelper.startPage(pageNum, 2);

??????????List<Emp> empList = service.getAllEmp();

??????????//使用pageInfo包装查询后的结果，封装了详细的查询数据，其中参数5是页码导航连续显示的页数

??????????PageInfo<Emp> pageInfo = new 
PageInfo<>(empList,5);

??????????String page = PageUtil.getPageInfo(pageInfo, 
request);

??????????map.put("empList", empList);

??????????map.put("page", page);

??????????return "list";

?????}

MyBatis逆向工程与分页插件

原文：https://www.cnblogs.com/suit000001/p/13334924.html