前言：
对于springboot的启动失败，相信大家都有经历，但是为什么会启动失败，以及怎么解决都只能通过日志进行查看，在这里，我会将常见的springboot启动失败的报错一一展示
报错：
1：端口占用报错
*************************** APPLICATION FAILED TO START *************************** Description: The Tomcat connector configured to listen on port 8987 failed to start. The port may already be in use or the connector may be misconfigured. // 配置为监听端口8987的Tomcat连接器启动失败。端口可能已经在使用中，或者连接器可能配置错误。 Action: Verify the connector's configuration, identify and stop any process that's liste ning on port 8987, or configure this application to listen on another port. // 验证连接器的配置，识别并停止端口8987上正在运行的任何进程，或将此应用程序配置为监听另一个端口。
- 报错：The port may already be in use —> 端口可能已经在使用中
- 原因：8987 端口被占用
- 解决：给springboot换一个端口或关闭占用端口的程序。
2：mapper扫描类报错
*************************** APPLICATION FAILED TO START *************************** Description: Field clustersDetailsAmqMapper in com.ruoyi.clusters.service.impl.ClustersDetailsAmqServiceImpl required a bean of type 'com.ruoyi.clusters.mapper.ClustersDetailsAmqMapper' that could not be found. // 在 com.ruoyi.clusters.service.impl.ClustersDetailsAmqServiceImpl 中的属性 clustersDetailsAmqMapper 需要一个类型为'com.ruoyi.clusters.mapper.ClustersDetailsAmqMapper'的bean，但是找不到它。 The injection point has the following annotations: - @org.springframework.beans.factory.annotation.Autowired(required=true) // 注入点具有以下注释：-@org.springframework.beans.factory.annotation.Autowired（必需=true） Action: Consider defining a bean of type 'com.ruoyi.clusters.mapper.ClustersDetailsAmqMapper' in your configuration. // 考虑在配置中定义一个类型为'com.ruoyi.clusters.mapper.ClustersDetailsAmqMapper'的bean。
- 报错：Field xxxMapper in xxx required a bean of type ‘xxxMapper’ that could not be found. —> 在xxx中的属性xxxMapper 需要一个类型为’xxxMapper’的 bean，但是找不到它。
- 原因：springboot的启动类 没有配置mapper扫描路径 或 配置的mapper文件扫描路径不对。
- 解决：在springboot启动类中 配置正确的mapper文件扫描，如下：
@SpringBootApplication
@MapperScan(value = "com.ruoyi.**.mapper")
// 路径必须与mapper文件在的路径一致，否则依然会报错
public class RuoYiApplication {
public static void main(String[] args) {
SpringApplication.run(RuoYiApplication.class, args);
}
}
注意：* 指的是下一级目录，** 指的是包含其子目录在内的。
如果Mapper文件在com.ruoyi.testa.mapper中，用@MapperScan(value = “com.ruoyi.*.mapper”) 是可以的，
如果文件是在com.ruoyi.testa.mytest.mapper中，1个 * 配置依然会找不到这个Mapper文件，会报同样的错误，应该用**，@MapperScan(value = “com.ruoyi.**.mapper”)。
3.数据库连接问题
*************************** APPLICATION FAILED TO START *************************** Description: Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured. // 配置数据源失败：没有指定'url'属性，无法配置嵌入的数据源。 Reason: Failed to determine a suitable driver class // 原因：无法确定合适的驱动程序类 Action: Consider the following: If you want an embedded database (H2, HSQL or Derby), please put it on the classpath. If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active). // 请考虑以下几点： // 如果你想要嵌入式数据库（H2、HSQL或Derby），请把它放在classpath(类路径)上。 // 如果要从特定配置文件加载数据库设置，则可能需要激活它（当前没有配置文件处于活动状态）。
报错：Failed to determine a suitable driver class —> 没法确定合适的驱动程序类
原因：没有在application.yml中配置数据源（比如druid连接池）或 数据库驱动（比如mysql）
加上数据源配置：
# 数据源配置
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.cj.jdbc.Driver
druid:
# 主库数据源
master:
url: jdbc:mysql://127.0.0.1:3306/car?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
username: root
password: root
加上数据库坐标：
mysqlmysql-connector-java
4：没有绑定连接池
***************************
APPLICATION FAILED TO START
***************************
Description:
Failed to bind properties under 'spring.datasource.type' to java.lang.Class:
// 没法把'spring.datasource.type'下的属性绑定到java.lang.Class：
Property: spring.datasource.type
// 属性：spring.datasource.type
Value: com.alibaba.druid.pool.DruidDataSource
// 值: com.alibaba.druid.pool.DruidDataSource
Origin: class path resource [application-druid.yml]:4:15
//来源: 类路径资源[application-druid.yml]：4:15
Reason: No converter found capable of converting from type [java.lang.String] to type [java.lang.Class]
// 原因：找不到能够从类型[java.lang.String]转换为类型[java.lang.Class]的转换器
Action:
Update your application's configuration
// 更新应用程序的配置
原因：没导入Druid连接池的坐标，所以找不到com.alibaba.druid.pool.DruidDataSource，把Druid连接池的坐标正确导入即可
com.alibabadruid-spring-boot-starter
5：无法确定合适的jdbc url
*************************** APPLICATION FAILED TO START *************************** Description: Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured. // 配置数据源失败：没有指定“url”属性，无法配置嵌入的数据源。 Reason: Failed to determine suitable jdbc url // 原因：无法确定合适的jdbc url Action: Consider the following: If you want an embedded database (H2, HSQL or Derby), please put it on the classpath. If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active). // 请考虑以下几点： // 如果你想要嵌入式数据库（H2、HSQL或Derby），请把它放在类路径上。 // 如果要从特定配置文件加载数据库设置，则可能需要激活它（当前没有激活的配置文件）。
报错：Failed to determine suitable jdbc url —> 无法确定合适的jdbc url
原因：
url没有被读取到，配置文件没有生效，其大概原因有以下几点：
系统编码不正确。跑项目之前最好让项目与文件的编码对应起来
可能有和你所在项目平级的配置文件，springboot会优先读取项目同级别目录下的配置文件
idea没有将resource设置为资源目录
检查DruidConfig配置类（或配置文件）
检查一下Application启动文件的位置，建议将其放在外层：如果SpringBootApplication启动文件位置在数据库配置DruidConfig文件下层，则不会对这个Configuration进行扫描，然后去找默认的配置，所以导致Failed to determine suitable jdbc url
6：自定义数据源一定要排除SpringBoot自动配置数据源，不然会出现循环引用的问题
Description:
The dependencies of some of the beans in the application context form a cycle:
// 应用程序上下文中某些bean的依赖关系形成一个循环：
testAController (field private com.ruoyi.testa.service.TestAService com.ruoyi.apis.TestAController.testAService)
↓
testAServiceImpl (field private com.ruoyi.testa.mapper.TestAMapper com.ruoyi.testa.service.impl.TestAServiceImpl.testAMapper)
↓
testAMapper defined in file [E:IdeaProjects2018carruoyi-mappertargetclassescomruoyitestamapperTestAMapper.class]
↓
sqlSessionFactory defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]
┌─────┐
| dynamicDataSource defined in class path resource [com/ruoyi/config/DruidConfig.class]
↑ ↓
| masterDataSource defined in class path resource [com/ruoyi/config/DruidConfig.class]
↑ ↓
| org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker
└─────┘
- 异常出现场景：SpringBoot中自定义DataSource数据源
- 原因：自定义数据源一定要排除SpringBoot自动配置数据源，不然会出现循环引用的问题。
- 解决：排除Spring Boot数据源自动配置类
@SpringBootApplication(exclude = { DataSourceAutoConfiguration.class })
@MapperScan(value = "com.ruoyi.**.mapper")
public class RuoYiApplication {
public static void main(String[] args) {
SpringApplication.run(RuoYiApplication.class, args);
}
}
7：由于缺少ServletWebServerFactory bean，无法启动ServletWebServerApplicationContext
. ____ _ __ _ _ /\ / ___'_ __ _ _(_)_ __ __ _ ( ( )___ | '_ | '_| | '_ / _` | \/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |___, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.0.3.RELEASE) 2020-09-01 11:21:54.103 INFO 21308 --- [ main] com.smr.bluetooth.DeviceCommApplication : Starting DeviceCommApplication on LAPTOP-RM7CN477 with PID 21308 (E:IdeaProjects2018bluetooth_testtargetclasses started by 且随疾风前行 in E:IdeaProjects2018bluetooth_test) 2020-09-01 11:21:54.106 INFO 21308 --- [ main] com.smr.bluetooth.DeviceCommApplication : No active profile set, falling back to default profiles: default 2020-09-01 11:21:54.133 INFO 21308 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@770c2e6b: startup date [Tue Sep 01 11:21:54 CST 2020]; root of context hierarchy 2020-09-01 11:21:54.232 WARN 21308 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean. 2020-09-01 11:21:54.605 ERROR 21308 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean. at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:155) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at com.smr.bluetooth.DeviceCommApplication.main(DeviceCommApplication.java:10) [classes/:na] Caused by: org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean. at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getWebServerFactory(ServletWebServerApplicationContext.java:204) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:178) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE] ... 8 common frames omitted
报错：Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean. （由于缺少ServletWebServerFactory bean，无法启动ServletWebServerApplicationContext）
解决：启动类添加@EnableAutoConfiguration注解即可解决问题
8：依赖冲突
*************************** APPLICATION FAILED TO START *************************** Description: An attempt was made to call a method that does not exist. The attempt was made from the following location: org.apache.catalina.authenticator.AuthenticatorBase.startInternal(AuthenticatorBase.java:1319) The following method did not exist: javax.servlet.ServletContext.getVirtualServerName()Ljava/lang/String; The calling method's class, org.apache.catalina.authenticator.AuthenticatorBase, was loaded from the following location: jar:file:/E:/Maven/maven-repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.63/tomcat-embed-core-9.0.63.jar!/org/apache/catalina/authenticator/AuthenticatorBase.class The called method's class, javax.servlet.ServletContext, is available from the following locations: jar:file:/E:/Maven/maven-repository/org/apache/tomcat/servlet-api/6.0.18/servlet-api-6.0.18.jar!/javax/servlet/ServletContext.class jar:file:/E:/Maven/maven-repository/org
- 报错：An attempt was made to call a method that does not exist.（试图调用不存在的方法。）
- 原因：依赖冲突
- 解决：
- 1.先重新编译运行试下
2.排查是否是版本不兼容、版本冲突等
以上就是SpringBoot启动失败的原因及其解决方法的详细内容，更多关于SpringBoot启动失败的资料请关注IT俱乐部其它相关文章！
