MyBatis Generator报错：Cannot instantiate object of type

[ERROR] Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli) on project myssm: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate failed: Cannot instantiate object of type: ClassNotFoundException -> [Help 1] org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli) on project myssm: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate failed: Cannot instantiate object of type at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80) at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288) at org.apache.maven.cli.MavenCli.main(MavenCli.java:199) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) at org.codehaus.classworlds.Launcher.main(Launcher.java:47) Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate failed: Cannot instantiate object of type at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:145) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207) ... 21 more Caused by: java.lang.RuntimeException: Cannot instantiate object of type at org.mybatis.generator.internal.ObjectFactory.createInternalObject(ObjectFactory.java:217) at org.mybatis.generator.codegen.mybatis3.IntrospectedTableMyBatis3SimpleImpl.createJavaClientGenerator(IntrospectedTableMyBatis3SimpleImpl.java:73) at org.mybatis.generator.codegen.mybatis3.IntrospectedTableMyBatis3Impl.requiresXMLGenerator(IntrospectedTableMyBatis3Impl.java:304) at org.mybatis.generator.config.Context.validate(Context.java:229) at org.mybatis.generator.config.Configuration.validate(Configuration.java:94) at org.mybatis.generator.api.MyBatisGenerator.<init>(MyBatisGenerator.java:118) at org.mybatis.generator.maven.MyBatisGeneratorMojo.execute(MyBatisGeneratorMojo.java:200) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134) ... 22 more Caused by: java.lang.ClassNotFoundException: at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at org.mybatis.generator.internal.ObjectFactory.internalClassForName(ObjectFactory.java:169) at org.mybatis.generator.internal.ObjectFactory.createInternalObject(ObjectFactory.java:213) ... 29 more

 

错误分析

在MyBatis-Generator的配置文件generatorConfig.xml中，没有给javaClientGenerator标签配置正确的type属性。示例：

<!--JavaDao层接口(XxxxDao.java)生成配置 targetProject+targetPackage构成全路径-->
<javaClientGenerator targetPackage="pers.hanchao.myssm.test.generator.dao" targetProject="src\main\java" type="">
    <!--是否允许建立子包（对应MySql的scheme）-->
    <property name="enableSubPackages" value="true"/>
</javaClientGenerator>

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3.错误解决

给javaClientGenerator标签配置正确的type属性即可。 
使用的targetRuntime="MyBatis3Simple"，有以下两种可选type。

• XMLMAPPER：生成的对象是 MyBatis 3.x 映射器基础结构的 Java接口和XML映射文件。
• ANNOTATEDMAPPER：生成的对象是 MyBatis 3.x 映射器基础结构的Java接口（使用注解），无XML文件。

习惯使用XMLMAPPER，配置如下：

<!--JavaDao层接口(XxxxDao.java)生成配置 targetProject+targetPackage构成全路径-->
<javaClientGenerator targetPackage="pers.hanchao.myssm.test.generator.dao" targetProject="src\main\java" type="XMLMAPPER">
    <!--是否允许建立子包（对应MySql的scheme）-->
    <property name="enableSubPackages" value="true"/>
</javaClientGenerator>