最后运行不成功 找不到问题在哪了？？？？不知道什么原因启动不了server。private UserDOMapper userDOMapper;这个总是红色

package com.example.demo;

import com.example.demo.dao.UserDOMapper;
import com.example.demo.dataobject.UserDO;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


@SpringBootApplication(scanBasePackages = {"com.example.demo"})
@RestController
@MapperScan("com.example.demo.dao")
public class DemoApplication {

    @Autowired
    private UserDOMapper userDOMapper;

    @RequestMapping("/")
    public String home() {
        UserDO userDO = userDOMapper.selectByPrimaryKey(1);
        if(userDO == null) {
            return "用户不存在";
        }else{
            return userDO.getName();
        }
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
        System.out.println("hello springboot");
    }

}

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-11-26 20:35:00.180 ERROR 1320 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoApplication': Unsatisfied dependency expressed through field 'userDOMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userDOMapper' defined in file [C:\Users\IdeaProjects\demo\target\classes\com\example\demo\dao\UserDOMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 4; columnNumber: 67; External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1415) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925) ~[spring-context-5.3.1.jar:5.3.1]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.1.jar:5.3.1]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) [spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) [spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) [spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1309) [spring-boot-2.4.0.jar:2.4.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1298) [spring-boot-2.4.0.jar:2.4.0]
    at com.example.demo.DemoApplication.main(DemoApplication.java:32) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_251]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_251]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_251]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_251]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.4.0.jar:2.4.0]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userDOMapper' defined in file [C:\Users\IdeaProjects\demo\target\classes\com\example\demo\dao\UserDOMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 4; columnNumber: 67; External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1518) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1401) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1367) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.1.jar:5.3.1]
    ... 25 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 4; columnNumber: 67; External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1179) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:571) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1367) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1503) ~[spring-beans-5.3.1.jar:5.3.1]
    ... 36 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 4; columnNumber: 67; External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.1.jar:5.3.1]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651) ~[spring-beans-5.3.1.jar:5.3.1]
    ... 49 common frames omitted
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 4; columnNumber: 67; External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:263) ~[mybatis-3.5.6.jar:3.5.6]
    at org.apache.ibatis.parsing.XPathParser.<init>(XPathParser.java:127) ~[mybatis-3.5.6.jar:3.5.6]
    at org.apache.ibatis.builder.xml.XMLConfigBuilder.<init>(XMLConfigBuilder.java:82) ~[mybatis-3.5.6.jar:3.5.6]
    at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:518) ~[mybatis-spring-2.0.6.jar:2.0.6]
    at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:491) ~[mybatis-spring-2.0.6.jar:2.0.6]
    at org.mybatis.spring.SqlSessionFactoryBean.getObject(SqlSessionFactoryBean.java:633) ~[mybatis-spring-2.0.6.jar:2.0.6]
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration.sqlSessionFactory(MybatisAutoConfiguration.java:179) ~[mybatis-spring-boot-autoconfigure-2.1.4.jar:2.1.4]
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$ccf0db60.CGLIB$sqlSessionFactory$1(<generated>) ~[mybatis-spring-boot-autoconfigure-2.1.4.jar:2.1.4]
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$ccf0db60$$FastClassBySpringCGLIB$$20ea1dd0.invoke(<generated>) ~[mybatis-spring-boot-autoconfigure-2.1.4.jar:2.1.4]
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.3.1.jar:5.3.1]
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.3.1.jar:5.3.1]
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$ccf0db60.sqlSessionFactory(<generated>) ~[mybatis-spring-boot-autoconfigure-2.1.4.jar:2.1.4]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_251]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_251]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_251]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_251]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.1.jar:5.3.1]
    ... 50 common frames omitted
Caused by: org.xml.sax.SAXParseException: External DTD: Failed to read external DTD 'mybatis-generator-config_1_0.dtd', because 'http' access is not allowed due to restriction set by the accessExternalDTD property.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:204) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:178) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1472) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1157) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1045) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:959) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:142) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:244) ~[na:1.8.0_251]
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339) ~[na:1.8.0_251]
    at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:261) ~[mybatis-3.5.6.jar:3.5.6]
    ... 66 common frames omitted


Process finished with exit code 0