MyBatis Generator程式碼生成配置
阿新 • • 發佈：2018-11-25
官方文件學習：http://www.mybatis.org/generator/configreference/xmlconfig.html
1、generatorConfig.xml 配置參考如下（都是通用配置，稍微修改即可使用）：
<?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="test" targetRuntime="MyBatis3"> <property name="javaFileEncoding" value="UTF-8" /> <!-- <plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin"></plugin> --> <!-- <plugin type="org.mybatis.generator.plugins.ToStringPlugin"></plugin> --> <plugin type="org.mybatis.generator.plugins.SerializablePlugin"></plugin> <commentGenerator> <property name="suppressDate" value="true" /> <!-- 是否去除自動生成的註釋 true：是 ： false:否 --> <property name="suppressAllComments" value="false" /> </commentGenerator> <!--資料庫連結URL，使用者名稱、密碼 --> <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mybatisdb" userId="root" password="123456"> </jdbcConnection> <javaTypeResolver> <!-- 預設false，把JDBC DECIMAL 和 NUMERIC 型別解析為 Integer，為 true時把JDBC DECIMAL 和 NUMERIC 型別解析為java.math.BigDecimal --> <property name="forceBigDecimals" value="false" /> </javaTypeResolver> <!-- 生成模型的包名和位置 --> <javaModelGenerator targetPackage="com.cjh.pojo" targetProject="src/main/java"> <!-- 是否對model新增 建構函式 --> <property name="constructorBased" value="true" /> <!-- 是否允許子包，即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="true" /> <!-- 是否對類CHAR型別的列的資料進行trim操作 --> <property name="trimStrings" value="true" /> </javaModelGenerator> <!-- 生成對映檔案的包名和位置 --> <sqlMapGenerator targetPackage="com.cjh.mapping" targetProject="src/main/java"> <!-- 是否允許子包，即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="true" /> </sqlMapGenerator> <!-- 生成DAO的包名和位置 --> <javaClientGenerator type="XMLMAPPER" targetPackage="com.cjh.dao" implementationPackage="com.cjh.dao.impl" targetProject="src/main/java"> <!-- 是否允許子包，即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="true" /> </javaClientGenerator> <!-- 要生成哪些表 --> <table tableName="student" domainObjectName="Student" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" /> </context> </generatorConfiguration>
2、執行，生成程式碼
（1）如果通過maven方式生成程式碼，需要在pom配置新增mybatis-generator-maven-plugin外掛，參考如下：
<build> <plugins> <!-- 統一原始碼編譯輸出的JDK版本 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.2</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> <!-- 打包時跳過單元測試 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>2.19.1</version> <configuration> <skipTests>true</skipTests> </configuration> </plugin> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <dependencies> <!-- mysql-connector-java 依賴 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- mybatis-generator-core --> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> </dependency> </dependencies> <configuration> <!--generatorConfig.xml配置檔案的路徑 --> <configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile> <overwrite>true</overwrite> </configuration> </plugin> <!--mybatis-generator:generate --> </plugins> </build>
（2）如果通過java程式碼方式來生成，如下：
a.還需新增依賴，如下：
<dependencies> <!-- mybatis-generator-core --> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> </dependency> <!-- mysql-connector-java 依賴 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> </dependencies>
b.執行程式碼：
import java.io.InputStream;
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.internal.DefaultShellCallback;
public class Test {
public static void main(String[] args) {
try {
List<String> warnings = new ArrayList<String>();
boolean overwrite = true;
InputStream resourceAsStream = Test.class.getResourceAsStream("generatorConfig.xml");
ConfigurationParser cp = new ConfigurationParser(warnings);
Configuration config = cp.parseConfiguration(resourceAsStream);
DefaultShellCallback callback = new DefaultShellCallback(overwrite);
MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
myBatisGenerator.generate(null);
} catch (Exception e) {
e.printStackTrace();
}
}
}
3、自定義生成程式碼註釋
如何實現？
繼承org.mybatis.generator.internal.DefaultCommentGenerator類（預設）或實現org.mybatis.generator.api.CommentGenerator介面。重寫裡面的方法即可。建議參考org.mybatis.generator.internal.DefaultCommentGenerator類，進一步做修改即可，以免出錯。
參考（根據需要自己仿DefaultCommentGenerator重寫）：
package com.cjh.mybatis.generator;
import static org.mybatis.generator.internal.util.StringUtility.isTrue;
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.Method;
import org.mybatis.generator.api.dom.xml.XmlElement;
import org.mybatis.generator.config.PropertyRegistry;
/**
* 自定義註釋生成器
* @author 陳嘉豪
*
*/
public class MyDefaultCommentGenerator implements CommentGenerator {
private Properties properties;
private boolean suppressDate;
private boolean suppressAllComments;
public MyDefaultCommentGenerator() {
super();
properties = new Properties();
suppressDate = false;
suppressAllComments = false;
}
/**
* 新增屬性註釋
* @author 陳嘉豪
*(non-Javadoc)
* @see org.mybatis.generator.api.CommentGenerator#addFieldComment(org.mybatis.generator.api.dom.java.Field, org.mybatis.generator.api.IntrospectedTable, org.mybatis.generator.api.IntrospectedColumn)
*/
@Override
public void addFieldComment(Field field, IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
if (suppressAllComments) {
return;
}
field.addJavaDocLine("/**");
field.addJavaDocLine(" * " + introspectedColumn.getRemarks());
field.addJavaDocLine(" */");
}
@Override
public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
}
@Override
public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
innerClass.addJavaDocLine("/**");
sb.append(introspectedTable.getFullyQualifiedTable());
innerClass.addJavaDocLine(sb.toString());
innerClass.addJavaDocLine(" */");
}
@Override
public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
innerClass.addJavaDocLine("/**");
sb.append(introspectedTable.getFullyQualifiedTable());
innerClass.addJavaDocLine(sb.toString());
innerClass.addJavaDocLine(" */");
}
@Override
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));
}
@Override
public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
}
@Override
public void addGetterComment(Method method, IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
}
@Override
public void addSetterComment(Method method, IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
}
@Override
public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
}
@Override
public void addJavaFileComment(CompilationUnit compilationUnit) {
}
@Override
public void addComment(XmlElement xmlElement) {
}
@Override
public void addRootComment(XmlElement rootElement) {
}
protected String getDateString() {
if (suppressDate) {
return null;
} else {
return new Date().toString();
}
}
}
寫完之後，還需在配置檔案修改如下，指定type，值就是自定義註釋生成類的全路徑，如下：
<commentGenerator type="com.cjh.mybatis.generator.MyDefaultCommentGenerator">
<property name="suppressDate" value="true" />
<!-- 是否去除自動生成的註釋 true：是 ： false:否 -->
<property name="suppressAllComments" value="false" />
</commentGenerator>4、可能出現的問題
（1）執行異常：Cannot instantiate object of type com.cjh.mybatis.generator.MyDefaultCommentGenerator
解決:將自定義的註釋生成器類打包生成jar,然後在pom檔案mybatis-generator-maven-plugin外掛中新增該依賴。