我正在按照此https://spring.io/guides/gs/accessing-data-mysql/指南将mysql数据库连接到spring启动项目
但是在运行应用程序时遇到以下错误，我正在生成spring starter项目，只在通过spring工具套件创建项目时选择web，mysql和jpa框
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class HttpSessionConfig {
private static final Map<String, HttpSession> sessions = new HashMap<>();
public List<HttpSession> getActiveSessions() {
return new ArrayList<>(sessions.values());
}
@Bean
public HttpSessionListener httpSessionListener() {
return new HttpSessionListener() {
@Override
public void sessionCreated(HttpSessionEvent hse) {
sessions.put(hse.getSession().getId(), hse.getSession());
}
@Override
public void sessionDestroyed(HttpSessionEvent hse) {
sessions.remove(hse.getSession().getId());
}
};
}
}
以下是application.properties
2018-03-28 16:48:42.125 ERROR 15452 --- [ main] com.zaxxer.hikari.HikariConfig : Failed to load driver class com.mysql.jdbc.Driver from HikariConfig class classloader jdk.internal.loader.ClassLoaders$AppClassLoader@782830e
2018-03-28 16:48:42.128 WARN 15452 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under '' to com.zaxxer.hikari.HikariDataSource
2018-03-28 16:48:42.130 INFO 15452 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2018-03-28 16:48:42.142 INFO 15452 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-03-28 16:48:42.143 ERROR 15452 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Failed to bind properties under '' to com.zaxxer.hikari.HikariDataSource:
Property: driverclassname
Value: com.mysql.jdbc.Driver
Origin: "driverClassName" from property source "source"
Reason: Unable to set value for property driver-class-name
Action:
Update your application's configuration
和pom.xml
spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://localhost:3306/world
spring.datasource.username=root
spring.datasource.password=admin
编辑：在application.properties中添加了spring.datasource.driver-class-name = com.mysql.jdbc.Driver，错误仍然存在
<?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>
<groupId>proj.mine</groupId>
<artifactId>training-app-2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>training-app-2</name>
<description>traning practive app</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
答案 0 :(得分：11)
尝试添加mysql连接器驱动程序版本并从以下位置删除范围标记：
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
答案 1 :(得分：3)
似乎应用程序可能没有使用正确的类路径运行，因为它似乎很难找到mysql驱动程序。您是否尝试通过IDE运行应用程序？
尝试使用项目目录中的命令行通过maven运行应用程序：
./ mvnw spring-boot：run
如果这样可行则会导致IDE出现问题，因为某些原因它在运行应用程序时没有提供正确的类路径。我不熟悉STS，但在IntelliJ中有一些选项，比如＆＃34; auto import pom＆＃34;保持IDE的项目视图与pom同步。
答案 2 :(得分：3)
仅供参考，当我将Spring Boot应用程序从H2更改为mySQL时，遇到了类似的问题。
我正在使用Gradle（而不是Maven）。我也正在使用STS。
将它添加到build.gradle文件后，我只是忘记运行Refresh Gradle Project：
dependencies {
compile("org.springframework.boot:spring-boot-starter-web")
...
// Use MySQL Connector-J
compile 'mysql:mysql-connector-java'
在执行“刷新Gradle项目”并重建/重新启动我的应用程序后，问题消失了。
答案 3 :(得分：0)
也许您缺少MySQL连接器依赖项，所以将其添加到pom.xml文件的依赖项标签中，然后再次运行该项目。它可以解决您的问题。
`<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency> `
答案 4 :(得分：0)
使用数据库版本和数据库更新pom.xml文件：
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
答案 5 :(得分：0)
com.zaxxer.hikari。 HikariDataSource 需要 spring-boot-starter-data-jdbc 依赖项，因此请将其添加到您的 pom.xml 中>：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>