本文是對之前一篇文章的補(bǔ)充：
Spring Boot項目啟動失敗報：ERROR o.s.boot.SpringApplication - Application startup failed
根據(jù)多次經(jīng)驗格了，spring boot項目啟動時候報出UnsatisfiedDependencyException異常以及伴有 BeanInstantiationException: Failed to instantiate [org.mybatis.spring.SqlSessionTemplate] 的原因赁温，基本上是某個mapper.xml文件中存在錯誤举反，但是失敗后報出的異常又往往沒有指明錯誤報出的位置，這就給我們定位錯誤帶來了麻煩域蜗。
下面介紹一下今天解決項目啟動失敗時候得出的一種解決方式，前提是你的項目是使用配置類進(jìn)行配置的。
1盆赤、配置類源碼，該處定義了SqlSessionTemplate的對象創(chuàng)建以及SqlSessionFactory的對象創(chuàng)建的配置：
@Bean
SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slaverDataSource") DataSource slaverDataSource) {
SqlSessionFactory factory = null;
try {
SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
sessionFactoryBean.setDataSource(dynamicDataSource(masterDataSource, slaverDataSource));
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
org.springframework.core.io.Resource[] resources = resolver.getResources("classpath*:/*/mybatis/**/*.xml");
List<org.springframework.core.io.Resource> filterResourceList = new ArrayList<org.springframework.core.io.Resource>();
List<String> fileNameList = new ArrayList<String>();
for (int i = 0; i < resources.length; i++) {
org.springframework.core.io.Resource resource = resources[i];
if (!fileNameList.contains(resource.getFilename())) {
filterResourceList.add(resource);
fileNameList.add(resource.getFilename());
}
}
org.springframework.core.io.Resource[] result = new org.springframework.core.io.Resource[filterResourceList.size()];
sessionFactoryBean.setMapperLocations(filterResourceList.toArray(result));
factory = (SqlSessionFactory) sessionFactoryBean.getObject();
} catch (Exception e) {
e.printStackTrace();
}
return factory;
}
@Bean
public SqlSessionTemplate sqlSessionTemplate(@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slaverDataSource") DataSource slaverDataSource) {
return new SqlSessionTemplate(this.sqlSessionFactory(masterDataSource, slaverDataSource));
}
2歉眷、在上述代碼中factory = (SqlSessionFactory) sessionFactoryBean.getObject();處打斷點(diǎn)牺六，然后啟動項目，運(yùn)行到該處時候汗捡，F(xiàn)6執(zhí)行淑际，就會跳入異常catch打印處e.printStackTrace(); 繼續(xù)F6執(zhí)行，然后就打印出了我們所需要的異常信息了扇住，如下：
org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\xxx\xxx\xxx\xxx-common\target\classes\base\mybatis\ShiroUserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.yuedu.common.model.basics.BasicsMenu'. Cause: java.lang.ClassNotFoundException: Cannot find class: com.xxx.xxx.model.basics.BasicsMenu
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:522)
at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:381)
at org.mybatis.spring.SqlSessionFactoryBean.getObject(SqlSessionFactoryBean.java:546)
at com.xxx.xxx.config.SpringBootServiceConfig.sqlSessionFactory(SpringBootServiceConfig.java:326)
at com.xxx.xxx.config.SpringBootServiceConfig$$EnhancerBySpringCGLIB$$936c1517.CGLIB$sqlSessionFactory$2(<generated>)
at com.xxx.xxx.config.SpringBootServiceConfig$$EnhancerBySpringCGLIB$$936c1517$$FastClassBySpringCGLIB$$81c66a7c.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:356)
at com.xxx.xxx.config.SpringBootServiceConfig$$EnhancerBySpringCGLIB$$936c1517.sqlSessionFactory(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1214)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1199)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1214)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1214)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175)
at com.xxx.xxx.start.Application.main(Application.java:54)
從上面異常信息中的第一行春缕，就可以很明確看到問題出現(xiàn)在哪里了。
