实习小结（四）--- MyBatis Generator使用

第一次听闻MyBatis Generator插件非常惊讶，已经有这么便捷方式的工具经过数据库表来自动生成实体类，映射文件，接口以及帮助类，并且能够经过本身写方法来增长中文注释，遂来学习一波。首先先建一个Maven的java项目

项目的目录结构

一、首先是pom.xml中的配置

<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.sysystem</groupId> <artifactId>mybatisgenerator</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>mybatisgenerator</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.9</version> </dependency> </dependencies> </project>

二、MyCommentGenerator.java为生成中文注释的方法

package com.mybatis.generator; import static org.mybatis.generator.internal.util.StringUtility.isTrue; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Properties; import org.mybatis.generator.api.CommentGenerator; import org.mybatis.generator.api.IntrospectedColumn; import org.mybatis.generator.api.IntrospectedTable; import org.mybatis.generator.api.dom.java.CompilationUnit; import org.mybatis.generator.api.dom.java.Field; import org.mybatis.generator.api.dom.java.InnerClass; import org.mybatis.generator.api.dom.java.InnerEnum; import org.mybatis.generator.api.dom.java.JavaElement; import org.mybatis.generator.api.dom.java.Method; import org.mybatis.generator.api.dom.java.Parameter; import org.mybatis.generator.api.dom.xml.XmlElement; import org.mybatis.generator.config.MergeConstants; import org.mybatis.generator.config.PropertyRegistry; public class MyCommentGenerator implements CommentGenerator{ private Properties properties; private Properties systemPro; private boolean suppressDate; private boolean suppressAllComments; private String currentDateStr; public MyCommentGenerator() { super(); properties = new Properties(); systemPro = System.getProperties(); suppressDate = false; suppressAllComments = false; currentDateStr = (new SimpleDateFormat("yyyy-MM-dd")).format(new Date()); } public void addJavaFileComment(CompilationUnit compilationUnit) { // add no file level comments by default return; } /** * Adds a suitable comment to warn users that the element was generated, and * when it was generated. */ public void addComment(XmlElement xmlElement) { return; } public void addRootComment(XmlElement rootElement) { // add no document level comments by default return; } public void addConfigurationProperties(Properties properties) { this.properties.putAll(properties); suppressDate = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_DATE)); suppressAllComments = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_ALL_COMMENTS)); } /** * This method adds the custom javadoc tag for. You may do nothing if you do * not wish to include the Javadoc tag - however, if you do not include the * Javadoc tag then the Java merge capability of the eclipse plugin will * break. * * @param javaElement * the java element */ protected void addJavadocTag(JavaElement javaElement, boolean markAsDoNotDelete) { javaElement.addJavaDocLine(" *"); StringBuilder sb = new StringBuilder(); sb.append(" * "); sb.append(MergeConstants.NEW_ELEMENT_TAG); if (markAsDoNotDelete) { sb.append(" do_not_delete_during_merge"); } String s = getDateString(); if (s != null) { sb.append(' '); sb.append(s); } javaElement.addJavaDocLine(sb.toString()); } /** * This method returns a formated date string to include in the Javadoc tag * and XML comments. You may return null if you do not want the date in * these documentation elements. * * @return a string representing the current timestamp, or null */ protected String getDateString() { String result = null; if (!suppressDate) { result = currentDateStr; } return result; } public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); innerClass.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedTable.getFullyQualifiedTable()); sb.append(" "); sb.append(getDateString()); innerClass.addJavaDocLine(sb.toString().replace("\n", " ")); innerClass.addJavaDocLine(" */"); } public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); innerEnum.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedTable.getFullyQualifiedTable()); innerEnum.addJavaDocLine(sb.toString().replace("\n", " ")); innerEnum.addJavaDocLine(" */"); } public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); field.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedColumn.getRemarks()); field.addJavaDocLine(sb.toString().replace("\n", " ")); field.addJavaDocLine(" */"); } public void addFieldComment(Field field, IntrospectedTable introspectedTable) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); field.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedTable.getFullyQualifiedTable()); field.addJavaDocLine(sb.toString().replace("\n", " ")); field.addJavaDocLine(" */"); } public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) { if (suppressAllComments) { return; } method.addJavaDocLine("/**"); addJavadocTag(method, false); method.addJavaDocLine(" */"); } public void addGetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { if (suppressAllComments) { return; } method.addJavaDocLine("/**"); StringBuilder sb = new StringBuilder(); sb.append(" * "); sb.append(introspectedColumn.getRemarks()); method.addJavaDocLine(sb.toString().replace("\n", " ")); sb.setLength(0); sb.append(" * @return "); sb.append(introspectedColumn.getActualColumnName()); sb.append(" "); sb.append(introspectedColumn.getRemarks()); method.addJavaDocLine(sb.toString().replace("\n", " ")); method.addJavaDocLine(" */"); } public void addSetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { if (suppressAllComments) { return; } method.addJavaDocLine("/**"); StringBuilder sb = new StringBuilder(); sb.append(" * "); sb.append(introspectedColumn.getRemarks()); method.addJavaDocLine(sb.toString().replace("\n", " ")); Parameter parm = method.getParameters().get(0); sb.setLength(0); sb.append(" * @param "); sb.append(parm.getName()); sb.append(" "); sb.append(introspectedColumn.getRemarks()); method.addJavaDocLine(sb.toString().replace("\n", " ")); method.addJavaDocLine(" */"); } public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); innerClass.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedTable.getFullyQualifiedTable()); innerClass.addJavaDocLine(sb.toString().replace("\n", " ")); sb.setLength(0); sb.append(" * @author "); sb.append(systemPro.getProperty("user.name")); sb.append(" "); sb.append(currentDateStr); innerClass.addJavaDocLine(" */"); } }

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三、在resources下增长配置信息generatorConfig.xml

<?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="context1" targetRuntime="MyBatis3">

    <!-- 指定生成的java文件的编码,没有直接生成到项目时中文可能会乱码 -->
    <property name="javaFileEncoding" value="UTF-8"/>
    
    <!-- 生成的pojo，将implements Serializable-->    
    <plugin type="org.mybatis.generator.plugins.SerializablePlugin"></plugin>
    
    <!-- 注释, 这里的type里写的是你的实现类的类全路径 -->
    <commentGenerator type="com.mybatis.generator.MyCommentGenerator"></commentGenerator>

    <!-- 数据库链接 mysql配置 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/studentmanager" userId="root" password="root">
        <property name="useInformationSchema" value="true"></property>
    </jdbcConnection>

    <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer true，把JDBC DECIMAL 和 NUMERIC 类型解析为java.math.BigDecimal -->
    <javaTypeResolver>
        <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>
    
    <!-- 生成model模型，对应的包路径，以及文件存放路径(targetProject)，targetProject能够指定具体的路径 也能够使用“MAVEN”来自动生成，这样生成的代码会在target/generatord-source目录下 --> 
    <javaModelGenerator targetPackage="model" targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
        <!-- 从数据库返回的值被清理先后的空格 -->
        <property name="trimStrings" value="true" />
    </javaModelGenerator>
    
    <!--对应的mapper.xml文件 -->
    <sqlMapGenerator targetPackage="mapper" targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
    </sqlMapGenerator>
    
    <!-- 对应的Mapper接口类文件 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="dao" targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 生成哪些些表，tableName对应数据库表，domainObjectName对应实体类名 -->
    <table schema="" tableName="emp" domainObjectName="Emp" enableCountByExample="true" enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true">
    </table>

  </context>
</generatorConfiguration>

四、最后编写一个mian方法用来生成须要的文件

package com.mybatis.generator; import java.io.IOException; import java.io.InputStream; import java.net.URISyntaxException; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import org.mybatis.generator.api.MyBatisGenerator; import org.mybatis.generator.config.Configuration; import org.mybatis.generator.config.xml.ConfigurationParser; import org.mybatis.generator.exception.InvalidConfigurationException; import org.mybatis.generator.exception.XMLParserException; import org.mybatis.generator.internal.DefaultShellCallback; public class StartUp { public static void main(String[] args) throws URISyntaxException { try { List<String> warnings = new ArrayList<String>(); boolean overwrite = true; ClassLoader classloader = Thread.currentThread().getContextClassLoader(); InputStream is = classloader.getResourceAsStream("generatorConfig.xml"); ConfigurationParser cp = new ConfigurationParser(warnings); Configuration config = cp.parseConfiguration(is); DefaultShellCallback callback = new DefaultShellCallback(overwrite); MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings); myBatisGenerator.generate(null); } catch (SQLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } catch (InvalidConfigurationException e) { e.printStackTrace(); } catch (XMLParserException e) { e.printStackTrace(); } } }

 

运行StartUp就会生成所须要的实体类，映射文件等

 

分享GitHub上找到的一个web 形式的mybatis 生成器：

https://github.com/huzhicheng/kite-mybatis-builder

 

参考博客

[1]Mybatis Generator的model生成中文注释,支持oracle和mysql(经过实现CommentGenerator接口的方法来实现)

http://www.cnblogs.com/NieXiaoHui/p/6094144.html

[2]MyBatis Generator 配置详解

https://blog.csdn.net/testcs_dn/article/details/79295065