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Mybatis generator生成工具简单介绍

Mybatis generator

　　 其主要的功能就是方便，快捷的创建好 Dao，entry，xml 加快了开发速度，使用方面根据其提供的规则配置好就 OK

　　这里还有一个重要的开发场景，开发过程中，对数据库的操作肯定很多，比如新增字段什么的，你只要将原先自动生成的一套代码删除，重新再生成一份，这就完美解决了，但是这样做的前提是，你必须对生成后的代码不改动，只是使用。不需要想手动开发写代码那样到处改代码，还担心改漏地方。

　　其实这个的实现方式也是五花八门的，写一种比较常见的

 主要流程

　　第一步：添加依赖

　　主要是 jdbc 和 generator

<!-- https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core -->
<dependency>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-core</artifactId>
    <version>1.3.6</version>
</dependency>

<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>

　　　第二步：配置 generatorConfig.xml 

　　　　这个文件主要是对  从哪来，到哪去的描述，还有一些特殊要求的配置

<?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">
        <!-- 生成 mysql 带有分页的 sql 的插件  这个可以自己写，-->
        <plugin type="generator.MysqlPaginationPlugin" />
        <plugin type="org.mybatis.generator.plugins.ToStringPlugin" />
        <plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
        <!-- 自定义的注释规则，继承 DefaultCommentGenerator 重写 一些方法 -->
        <commentGenerator type="generator.NewbatisGenerator">
            <!-- 是否去除自动生成日期的注释 true：是 ： false: 否 -->
            <property name="suppressDate" value="true"/>
            <!-- 是否去除所有自动生成的注释 true：是 ： false: 否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql:// 数据库地址"
                        userId="username"
                        password="password">
        </jdbcConnection>
        <!--生成 entity 类存放位置-->
        <javaModelGenerator targetPackage="包名（com.generator.test.entity）" targetProject="项目地址到 \java （D:\workspace\src\main\java）">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!--生成映射文件存放位置-->
        <sqlMapGenerator targetPackage="包名（com.generator.test.mapper）" targetProject="项目地址到 \java （D:\workspace\src\main\java）">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!--生成 Dao 类存放位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="包名（com.generator.test.dao）"
                             targetProject="项目地址到 \java （D:\workspace\src\main\java）">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <table tableName="表名" domainObjectName="生成实体的类名">
        </table>
    </context>
</generatorConfiguration>

　　

 

　　　　第三步：主要看你个人的需求，对注释，分页啥的有啥要求不，可以重写几个方法对其进行改造

　　　　　　主要举几个例子  

　　　　对注释的修改 NewbatisGenerator 

public class NewbatisGenerator extends DefaultCommentGenerator {
    private Properties properties;
    private Properties systemPro;
    private boolean suppressDate;
    private boolean suppressAllComments;
    private String currentDateStr;

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> NewbatisGenerator() {
    </span><span style="color: rgba(0, 0, 255, 1)">super</span><span style="color: rgba(0, 0, 0, 1)">();
    properties </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Properties();
    systemPro </span>=<span style="color: rgba(0, 0, 0, 1)"> System.getProperties();
    suppressDate </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">;
    suppressAllComments </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">;
    currentDateStr </span>= (<span style="color: rgba(0, 0, 255, 1)">new</span> SimpleDateFormat("yyyy-MM-dd")).format(<span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Date());
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 对类的注解
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> topLevelClass
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> introspectedTable
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
@Override
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
    topLevelClass.addJavaDocLine(</span>"/**"<span style="color: rgba(0, 0, 0, 1)">);
    topLevelClass.addJavaDocLine(</span>" * 这是MyBatis Generator自动生成的Model Class."<span style="color: rgba(0, 0, 0, 1)">);

    StringBuilder sb </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> StringBuilder();
    sb.append(</span>" * 对应的数据表是 : "<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(introspectedTable.getFullyQualifiedTable());
    topLevelClass.addJavaDocLine(sb.toString());

    String tableRemarks </span>=<span style="color: rgba(0, 0, 0, 1)"> introspectedTable.getRemarks();
    </span><span style="color: rgba(0, 0, 255, 1)">if</span> (!<span style="color: rgba(0, 0, 0, 1)">StringUtils.isEmpty(tableRemarks)) {
        sb.setLength(</span>0<span style="color: rgba(0, 0, 0, 1)">);
        sb.append(</span>" * 数据表注释 : "<span style="color: rgba(0, 0, 0, 1)">);
        sb.append(tableRemarks);
        topLevelClass.addJavaDocLine(sb.toString());
    }

    sb.setLength(</span>0<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(</span>" * @author "<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(systemPro.getProperty(</span>"user.name"<span style="color: rgba(0, 0, 0, 1)">));
    topLevelClass.addJavaDocLine(sb.toString());

    String curDateString </span>= (<span style="color: rgba(0, 0, 255, 1)">new</span> SimpleDateFormat("yyyy-MM-dd HH🇲🇲ss")).format(<span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Date());
    sb.setLength(</span>0<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(</span>" * @date "<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(curDateString);
    topLevelClass.addJavaDocLine(sb.toString());

    topLevelClass.addJavaDocLine(</span>" */"<span style="color: rgba(0, 0, 0, 1)">);
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 生成的实体增加字段的中文注释
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> addFieldComment(Field field, IntrospectedTable introspectedTable,
                            IntrospectedColumn introspectedColumn) {
    </span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (suppressAllComments) {
        </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    StringBuilder sb </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> StringBuilder();
    field.addJavaDocLine(</span>"/**"<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(</span>" * "<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(introspectedColumn.getRemarks());
    field.addJavaDocLine(sb.toString().replace(</span>"\n", " "<span style="color: rgba(0, 0, 0, 1)">));
    field.addJavaDocLine(</span>" */"<span style="color: rgba(0, 0, 0, 1)">);
}



}

　　对分页的添加  MysqlPaginationPlugin  自动生成带分页插件

public class MysqlPaginationPlugin extends PluginAdapter {
    public MysqlPaginationPlugin(){}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span><span style="color: rgba(0, 0, 0, 1)"> modelExampleClassGenerated(TopLevelClass topLevelClass,
        IntrospectedTable introspectedTable) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.addLimit(topLevelClass, introspectedTable, "limitStart"<span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.addLimit(topLevelClass, introspectedTable, "limitSize"<span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">super</span><span style="color: rgba(0, 0, 0, 1)">.modelExampleClassGenerated(topLevelClass, introspectedTable);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span><span style="color: rgba(0, 0, 0, 1)"> sqlMapSelectByExampleWithoutBLOBsElementGenerated(XmlElement element,
        IntrospectedTable introspectedTable) {
    XmlElement isNotNullElement </span>= <span style="color: rgba(0, 0, 255, 1)">new</span> XmlElement("if"<span style="color: rgba(0, 0, 0, 1)">);
    isNotNullElement
            .addAttribute(</span><span style="color: rgba(0, 0, 255, 1)">new</span> Attribute("test", "limitStart != null and limitSize &gt;= 0"<span style="color: rgba(0, 0, 0, 1)">));
    isNotNullElement.addElement(</span><span style="color: rgba(0, 0, 255, 1)">new</span> TextElement("limit #{limitStart} , #{limitSize}"<span style="color: rgba(0, 0, 0, 1)">));
    element.addElement(isNotNullElement);
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">super</span><span style="color: rgba(0, 0, 0, 1)">.sqlMapSelectByExampleWithoutBLOBsElementGenerated(element, introspectedTable);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span><span style="color: rgba(0, 0, 0, 1)"> sqlMapSelectByExampleWithBLOBsElementGenerated(XmlElement element,
        IntrospectedTable introspectedTable) {
    XmlElement isNotNullElement </span>= <span style="color: rgba(0, 0, 255, 1)">new</span> XmlElement("if"<span style="color: rgba(0, 0, 0, 1)">);
    isNotNullElement
            .addAttribute(</span><span style="color: rgba(0, 0, 255, 1)">new</span> Attribute("test", "limitStart != null and limitSize &gt;= 0"<span style="color: rgba(0, 0, 0, 1)">));
    isNotNullElement.addElement(</span><span style="color: rgba(0, 0, 255, 1)">new</span> TextElement("limit #{limitStart} , #{limitSize}"<span style="color: rgba(0, 0, 0, 1)">));
    element.addElement(isNotNullElement);
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">super</span><span style="color: rgba(0, 0, 0, 1)">.sqlMapSelectByExampleWithBLOBsElementGenerated(element, introspectedTable);
}

</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> addLimit(TopLevelClass topLevelClass, IntrospectedTable introspectedTable,
        String name) {
    CommentGenerator commentGenerator </span>= <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.context.getCommentGenerator();
    Field field </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Field();
    field.setVisibility(JavaVisibility.PROTECTED);
    field.setType(PrimitiveTypeWrapper.getIntegerInstance());
    field.setName(name);
    commentGenerator.addFieldComment(field, introspectedTable);
    topLevelClass.addField(field);
    </span><span style="color: rgba(0, 0, 255, 1)">char</span> c = name.charAt(0<span style="color: rgba(0, 0, 0, 1)">);
    String camel </span>= Character.toUpperCase(c) + name.substring(1<span style="color: rgba(0, 0, 0, 1)">);
    Method method </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Method();
    method.setVisibility(JavaVisibility.PUBLIC);
    method.setName(</span>"set" +<span style="color: rgba(0, 0, 0, 1)"> camel);
    method.addParameter(</span><span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Parameter(PrimitiveTypeWrapper.getIntegerInstance(), name));
    StringBuilder sb </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> StringBuilder();
    sb.append(</span>"this."<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(name);
    sb.append(</span>" = "<span style="color: rgba(0, 0, 0, 1)">);
    sb.append(name);
    sb.append(</span>";"<span style="color: rgba(0, 0, 0, 1)">);
    method.addBodyLine(sb.toString());
    commentGenerator.addGeneralMethodComment(method, introspectedTable);
    topLevelClass.addMethod(method);
    Method getterMethod </span>=<span style="color: rgba(0, 0, 0, 1)"> AbstractJavaGenerator.getGetter(field);
    commentGenerator.addGeneralMethodComment(getterMethod, introspectedTable);
    topLevelClass.addMethod(getterMethod);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span> validate(List&lt;String&gt;<span style="color: rgba(0, 0, 0, 1)"> warnings) {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">true</span><span style="color: rgba(0, 0, 0, 1)">;
}



</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 生成mapper.xml,文件内容会被清空再写入
 * </span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
@Override
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span><span style="color: rgba(0, 0, 0, 1)"> sqlMapGenerated(GeneratedXmlFile sqlMap, IntrospectedTable introspectedTable) {
    sqlMap.setMergeable(</span><span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">);
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">super</span><span style="color: rgba(0, 0, 0, 1)">.sqlMapGenerated(sqlMap, introspectedTable);
}



}

　　最后一步：运行生成

　　这些官网都是有的

public class Generator {

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">void</span> main(String[] args) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> Exception{
    List</span>&lt;String&gt; warnings = <span style="color: rgba(0, 0, 255, 1)">new</span> ArrayList&lt;String&gt;<span style="color: rgba(0, 0, 0, 1)">();
    </span><span style="color: rgba(0, 0, 255, 1)">boolean</span> overwrite = <span style="color: rgba(0, 0, 255, 1)">true</span><span style="color: rgba(0, 0, 0, 1)">;
    File configFile </span>= <span style="color: rgba(0, 0, 255, 1)">new</span> File("generatorConfig.xml"<span style="color: rgba(0, 0, 0, 1)">);
    ConfigurationParser cp </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> ConfigurationParser(warnings);
    Configuration config </span>=<span style="color: rgba(0, 0, 0, 1)"> cp.parseConfiguration(configFile);
    DefaultShellCallback callback </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> DefaultShellCallback(overwrite);
    MyBatisGenerator myBatisGenerator </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> MyBatisGenerator(config, callback, warnings);
    myBatisGenerator.generate(</span><span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">);

}



}

　　这个比较简单明了，个性化也不错，值得推荐

　　转载请注明出处：https://www.cnblogs.com/zhouguanglin/p/11239583.html