MyBatis-Generator的使用

刺骨的言语ヽ痛彻心扉 2022-01-14 23:41 287阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

《[Spring+SpringMVC+MyBatis整合][Spring_SpringMVC_MyBatis]》的补充之《MyBatis-Generator的使用》

## 一、在MyEclipse中使用 ##

楼主的MyEclipse版本是2014

### 1.下载安装MyBatis-Generator插件 ###

在Myeclipse中，Help->Install from site

![083627\_kPw0\_220508.png][083627_kPw0_220508.png]

在“Work with”输入“https://dl.bintray.com/mybatis/mybatis-generator/”，查询出下图中步骤2的结果后，点击“next”，之后继续“next”，直到“Finish”就可以了

![083915\_Zoi8\_220508.png][083915_Zoi8_220508.png]

完成后，重启MyEclipse。（你也可以去eclipse的插件市场（[http://marketplace.eclipse.org/content/mybatis-generator][http_marketplace.eclipse.org_content_mybatis-generator]），用别的方式安装）

### 2.使用 ###

右键项目，New->Other，选择“MyBatis Generator Configuration File”。在下一个界面中，Location选择你自己的项目，然后“Finish”。

![084224\_w3O1\_220508.png][084224_w3O1_220508.png] ![085330\_JNYV\_220508.png][085330_JNYV_220508.png]

在项目中就创建了一个generatorConfig.xml文件，我们把它补充完整

<?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 location="/Users/panjerry/Workspaces/Lib/MavenLib/mysql/mysql-connector-java/5.1.35/mysql-connector-java-5.1.35.jar"/>
    
        <context id="default" targetRuntime="MyBatis3">
            
            <commentGenerator>
                <property name="suppressDate" value="true"/>
                
            </commentGenerator>
    
            
            <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mytest" userId="root"
                            password="root">
            </jdbcConnection>
    
            
            <javaTypeResolver>
                <property name="forceBigDecimals" value="false"/>
            </javaTypeResolver>
    
            
            <javaModelGenerator targetPackage="com.jerrypanda.demo.javaweb.pojo" targetProject="myeclipse-maven/src/main/java">
                
                <property name="constructorBased" value="true"/>
                
                <property name="enableSubPackages" value="false"/>
                
                <property name="immutable" value="true"/>
                
                <property name="trimStrings" value="true"/>
                
                
            </javaModelGenerator>
    
            
            <sqlMapGenerator targetPackage="com.jerrypanda.demo.javaweb.mapper" targetProject="myeclipse-maven/src/main/java">
                <property name="enableSubPackages" value="false"/>
            </sqlMapGenerator>
    
    
            
            <javaClientGenerator targetPackage="com.jerrypanda.demo.javaweb.dao" targetProject="myeclipse-maven/src/main/java"
                                 type="XMLMAPPER">
                
                
                
                
                
                
                
            </javaClientGenerator>
    
            <table tableName="user"
                   enableCountByExample="false" enableUpdateByExample="false"
                   enableDeleteByExample="false" enableSelectByExample="false"
                   selectByExampleQueryId="false" >
                
                
    
                
                
    
                
                
    
                
                
            </table>
        </context>
    </generatorConfiguration>

其中数据库的地址账号密码替换成你自己的，我这里建了一个user表举例说明，然后配置其中的“ <table tableName="user"”部分

DROP TABLE IF EXISTS user; 
    CREATE TABLE `user` (  
      `id` int(11) NOT NULL AUTO_INCREMENT,  
      `user_name` varchar(40) NOT NULL,  
      `password` varchar(255) NOT NULL,  
      `age` int(4) NOT NULL,  
      PRIMARY KEY (`id`)  
    ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

然后右键generatorConfig.xml文件，选择“Generate MyBatis/iBATIS Artifacts”，就会生成相应的文件了

![090226\_h7Ba\_220508.png][090226_h7Ba_220508.png] ![090537\_OMAe\_220508.png][090537_OMAe_220508.png]

## 二、在IDEA中使用 ##

楼主的IDEA版本是14.1.6

### 1.建一个Maven项目 ###

### 2.修改pom.xml，引入mybatis-generator插件 ###

<?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>4.0.0</modelVersion>
    
        <groupId>com.jerrypanda</groupId>
        <artifactId>mybatis-generator</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <build>
            <finalName>BuildEnergy</finalName>
            <plugins>
                <plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <configuration>
                        <verbose>true</verbose>
                        <overwrite>true</overwrite>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
    </project>

### 3.在resources下创建generatorConfig.xml文件 ###

和MyEclipse中基本是一样的，唯一的差别是这里的“targetProject”不需要指定项目名称。

### 4.生成文件 ###

配置运行环境，如下图，选择“Edit Configurations”

![092044\_ryja\_220508.png][092044_ryja_220508.png]

然后选择增加maven运行环境

![092247\_9XBE\_220508.png][092247_9XBE_220508.png]

起个名字“generator”，在“Command line”输入“mybatis-generator:generate -e”然后，然后“OK”

![092451\_lOK9\_220508.png][092451_lOK9_220508.png]

回到IDEA的Maven管理界面，双击执行“generator”就可以了

![091612\_fMpO\_220508.png][091612_fMpO_220508.png]

## 三、注意 ##

如果设置suppressAllComments为true，\*Mapper.xml文件的内容不会被覆盖，只会追加

原因：org.mybatis.generator.internal.XmlFileMergerJaxp.java中的getMergedSource()方法中，先删除可以删除的原节点，再增加新的节点

public static String getMergedSource(InputSource newFile,
                InputSource existingFile, String existingFileName) throws IOException, SAXException,
                ParserConfigurationException, ShellException {
            ...
    
            // remove the old generated elements and any
            // white space before the old nodes
            List<Node> nodesToDelete = new ArrayList<Node>();
            NodeList children = existingRootElement.getChildNodes();
            int length = children.getLength();
            for (int i = 0; i < length; i++) {
                Node node = children.item(i);
                //判断是否需要删除节点
                if (isGeneratedNode(node)) {
                    nodesToDelete.add(node);
                } else if (isWhiteSpace(node)
                        && isGeneratedNode(children.item(i + 1))) {
                    nodesToDelete.add(node);
                }
            }
            //删除原来的节点
            for (Node node : nodesToDelete) {
                existingRootElement.removeChild(node);
            }
    
            // add the new generated elements
            ...
        }

而判断是否删除原节点的方法是isGeneratedNode(Node node)

private static boolean isGeneratedNode(Node node) {
            boolean rc = false;
            ...
    
                    for (int i = 0; i < length; i++) {
                        Node childNode = children.item(i);
                        if (isWhiteSpace(childNode)) {
                            continue;
                        } else if (childNode.getNodeType() == Node.COMMENT_NODE) {
                            Comment comment = (Comment) childNode;
                            String commentData = comment.getData();
                            //如果注释中包含 OLD_ELEMENT_TAGS = {"@ibatorgenerated", "@abatorgenerated", "@mbggenerated" } 中的任意一个，就不删除
                            for (String tag : MergeConstants.OLD_ELEMENT_TAGS) {
                                if (commentData.contains(tag)) {
                                    rc = true;
                                    break;
                                }
                            }
                        } else {
                            break;
                        }
                    }
            ...
            return rc;
        }

源码：[https://gitee.com/jppublic/MybatisGenerator.git][https_gitee.com_jppublic_MybatisGenerator.git]

源码说明：源码略有改动，扩展了一些功能

转载于:https://my.oschina.net/jerrypan/blog/868834

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220114/92341c6d85464a108ec43ed9f8cb5a62.png
[Spring_SpringMVC_MyBatis]: https://my.oschina.net/jerrypan/blog/868059
[083627_kPw0_220508.png]: https://static.oschina.net/uploads/space/2017/0328/083627_kPw0_220508.png
[083915_Zoi8_220508.png]: https://static.oschina.net/uploads/space/2017/0328/083915_Zoi8_220508.png
[http_marketplace.eclipse.org_content_mybatis-generator]: http://marketplace.eclipse.org/content/mybatis-generator
[084224_w3O1_220508.png]: https://static.oschina.net/uploads/space/2017/0328/084224_w3O1_220508.png
[085330_JNYV_220508.png]: https://static.oschina.net/uploads/space/2017/0328/085330_JNYV_220508.png
[090226_h7Ba_220508.png]: https://static.oschina.net/uploads/space/2017/0328/090226_h7Ba_220508.png
[090537_OMAe_220508.png]: https://static.oschina.net/uploads/space/2017/0328/090537_OMAe_220508.png
[092044_ryja_220508.png]: https://static.oschina.net/uploads/space/2017/0328/092044_ryja_220508.png
[092247_9XBE_220508.png]: https://static.oschina.net/uploads/space/2017/0328/092247_9XBE_220508.png
[092451_lOK9_220508.png]: https://static.oschina.net/uploads/space/2017/0328/092451_lOK9_220508.png
[091612_fMpO_220508.png]: https://static.oschina.net/uploads/space/2017/0328/091612_fMpO_220508.png
[https_gitee.com_jppublic_MybatisGenerator.git]: https://gitee.com/jppublic/MybatisGenerator.git