Tomcat 和 JDBC 驱动程序（可能存在内存泄漏）。应用程序无法启动

Question

我正在使用 Spring Boot 创建 Java 应用程序。我的应用程序无法启动。 这是我得到的错误：

2017-08-31 15:44:23.246  WARN 12484 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt:  org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Dbcp2.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.commons.dbcp2.BasicDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).
2017-08-31 15:44:23.249  INFO 12484 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2017-08-31 15:44:23.262  WARN 12484 --- [ost-startStop-1] o.a.c.loader.WebappClassLoaderBase       : The web application [ROOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 java.lang.Object.wait(Native Method)
 java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
  com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)
 2017-08-31 15:44:23.288  INFO 12484 --- [           main] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-08-31 15:44:23.294 ERROR 12484 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Cannot determine embedded database driver class for database type NONE

Action:

If you want an embedded database please put a supported one on the classpath.  If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).

据我了解，这里描述了解决方案：Why must the JDBC driver be put in TOMCAT_HOME/lib folder?

但是！我有 WEB-INF/lib 中的所有文件。根本没有Tomcat路径。所有 .jar 文件都在同一个 WEB-INF/lib 中。谁能解释一下具体应该怎么做？

下面是我的 .POM 文件：

 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0  http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<groupId>com.boris</groupId>
<artifactId>movie-project</artifactId>
<version>1.0-SNAPSHOT</version>

<build>

<plugins>
    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
            <source>1.6</source>
            <target>1.6</target>
        </configuration>
    </plugin>
</plugins>
</build>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>  
</dependency>

<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.6.2</version>
</dependency>

<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.5</version>
</dependency>

<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
</dependency>

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.5</version>
</dependency>


<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4.7</version>
</dependency>

<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>commons-net</groupId>
<artifactId>commons-net</artifactId>
<version>3.6</version>
</dependency>

<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.2.9.Final</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.3.7.RELEASE</version>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.1.1</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.7.RELEASE</version>
</dependency>

</dependencies>

    </project>

非常感谢您的帮助！

Answer 1

一般来说，对于应用程序服务，必须注意各种类加载器。如果您已经在应用程序一级以上的级别配置了 JDBC 资源，那么驱动程序也应该可用于应用程序一级以上的类加载器。

Answer 2

假设你没有指定任何数据源，Spring Boot 将尝试加载 H2 或 Derby，如果你在类路径中有任何一个。

鉴于你想使用mysql，你可能应该在application.properties中添加一个jdbc url..

“使用 SQL 数据”下的参考指南中有更多内容

https://docs.spring.io/spring-boot/docs/1.5.6.RELEASE/reference/htmlsingle/#boot-features-sql

Answer 3

感谢大家的帮助。但问题比我想象的要简单得多。 dbService 类没有得到它的属性，因为它没有看到我的 AppConfig 类。使用 @ComponentScan 解决了这个问题。