SSM学习15：MyBatis****,分页插件

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1.下载
https://github.com/mybatis/generator/releases
2.把相关jar导入到工程当中

mybatis-generator-core-1.3.7.jar

3.创建generatorConfig.xml 设置targetRuntime为MyBatisSimple则为简单的增删改查

<?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>

    <!--
    targetRuntime:设置自动生成的版本
    MyBatis3:
    MyBatis3Simple:简单增删改查
    -->
    <context id="DB2Tables" targetRuntime="MyBatis3">
        <!--
           不要生成日期和备注
        -->
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <property name="suppressAllComments" value="true" />
        </commentGenerator>

        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8"
                        userId="root"
                        password="1234">
        </jdbcConnection>

        <!--
        配置domain生成策略
        targetProject:把自动生成的domian放在哪个工程里面
        targetPackage:哪个包下

        -->
        <javaModelGenerator targetPackage="com.itlike.domain" targetProject=".\src">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!--
            配置mapper的生成策略
            targetPackage:把自动生成的mapper放在哪个工程里面
            targetProject:哪个包下
        -->
        <sqlMapGenerator targetPackage="com.itlike.mapper"  targetProject=".\src">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>
        <!--
            mapper接口生成策略
        -->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.itlike.mapper"  targetProject=".\src">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <table tableName="customer" domainObjectName="Customer" ></table>
        <table tableName="teacher" domainObjectName="Teacher" ></table>
        <table tableName="student" domainObjectName="Student" ></table>



    </context>

</generatorConfiguration>

4.编写生成代码

 		List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("./src/generatorConfig.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);

5.MyBatis3版本的简单实用（一般开发还是用simple版本的）
前面的targetRuntime改为MyBatis3后应该如何使用呢
每个类都会生成多一个Example的，这是可以类似hibernate一样使用

分页插件

把从数据库查询出来的记录分页
1.下载分页插件
https://github.com/pagehelper/Mybatis-PageHelper/blob/master/README_zh.md
2.配置分页插件
sqlMappingConfig.xml
位于environments标签之前



3在查询之前设置分页

 Page<Object> page = PageHelper.startPage(1, 5);

查询数据之后添加

PageInfo<Customer> pageInfo = new PageInfo<>(customers, 5);