数据库连接失败了这是为什么呢？HTTP状态 500 - 内部服务器错Connections could not be acquired from the underlying database!

Jenny_xuexi

已于 2022-08-04 11:31:24 修改

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分类专栏： java SSM 文章标签：数据库服务器 http java

于 2022-08-04 11:19:26 首次发布

本文链接：https://blog.youkuaiyun.com/Jenny_xuexi/article/details/126138444

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HTTP状态 500 - 内部服务器错误
Request processing failed; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!
描述服务器遇到一个意外的情况，阻止它完成请求。

需要换和数据库版本适应的mysq-connector-ava版本

在这里插入图片描述

然后又看了mysql的安装地址：https://jingyan.baidu.com/article/90bc8fc870f8eeb752640c29.html

在这里插入图片描述

**判断mysql是否安装成功，我参考了这个博客：https://blog.youkuaiyun.com/DS_zxm123/article/details/108006491?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522165951036616782246486822%2522%252C%2522scm%2522%253A%252220140713.130102334…%2522%257D&request_id=165951036616782246486822&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allsobaiduend~default-1-108006491-null-null.142^v39pc_rank_34_2&utm_term=%E6%9F%A5%E7%9C%8B%E6%95%B0%E6%8D%AE%E5%BA%93%E6%98%AF%E5%90%A6%E5%AE%89%E8%A3%85%E6%88%90%E5%8A%9F&spm=1018.2226.3001.4187

在这里插入图片描述

然后下图是我自己电脑的mysql的具体信息:

在这里插入图片描述

然后还是感觉是因为数据库的驱动版本与本地数据库版本不一致造成的这个错误，我电脑的数据库版本是5.7.20，所以我就去找与数据库版本对应的mysql-connector-java的驱动，然后手动下载驱动可以去以下的官网进行下载：1、maven仓库国内镜像地址 http://mvnrepository.com
2、https://classnotfound.com.cn 可以以类名或jar名模糊查询，可同时显示多个版本和pom文件，从pom文件可找到在github.com里的源码和使用说明
3、nowjava.com/jar jar包的使用方法描述很详细

然后我就去IDEA手动导入mysql的对应的jar包：

在这里插入图片描述

然后发现没有测试数据库连接，就接着进行数据库的链接测试了 在这里插入图片描述
数据库中的表导出sql语句，是这样子来导出的：

最后呢，以上的问题都不是，基于我的数据库版本是5.7.20，然后我的数据库驱动mysql-connector-java-8.0.13，然后呢其实版本是对应的呢，原因是：我的数据库驱动是放在了本地，并没有放到项目里面去，导致的这次错误！
在这里插入图片描述

下面是pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>spring_test</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>spring_test</name>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.target>1.8</maven.compiler.target>
        <maven.compiler.source>1.8</maven.compiler.source>
        <junit.version>5.8.1</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>javax.enterprise</groupId>
            <artifactId>cdi-api</artifactId>
            <version>2.0.SP1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.ws.rs</groupId>
            <artifactId>javax.ws.rs-api</artifactId>
            <version>2.1.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>


        <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.13</version>
            <!--<groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.7.20  5.1.32</version>-->
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.2.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.3</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.7</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>



        <!--最后出错因为没有加standard的依赖吗-->
<!--        <dependency>-->
<!--            <groupId>taglibs</groupId>-->
<!--            <artifactId>standard</artifactId>-->
<!--            <version>1.1.2</version>-->
<!--        </dependency>-->


    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.3.2</version>
            </plugin>
        </plugins>
    </build>
</project>

下面是spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
">

    <!--1、mvc注解驱动-->
    <mvc:annotation-driven/>

    <!--2、配置视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/pages/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--3、静态资源权限开放-->
    <mvc:default-servlet-handler/>

    <!--4、组件扫描  扫描Controller-->
    <context:component-scan base-package="com.ittaike.controller"/>


    <!--配置拦截器-->
    <!--<mvc:interceptors>
        <mvc:interceptor>
            &lt;!&ndash;对哪些资源执行拦截操作&ndash;&gt;
            <mvc:mapping path="/**"/>
            <bean class="com.ittaike.interceptor.MyInterceptor2"/>
        </mvc:interceptor>
        <mvc:interceptor>
            &lt;!&ndash;对哪些资源执行拦截操作&ndash;&gt;
            <mvc:mapping path="/**"/>
            <bean class="com.itheima.interceptor.MyInterceptor1"/>
        </mvc:interceptor>
    </mvc:interceptors>-->

</beans>

下面是applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
">


   <!--1、加载jdbc.properties-->
   <context:property-placeholder location="classpath:jdbc.properties"/>

    <!--2、配置数据源对象-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>


    <!--3、配置jdbctemplate对象-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource">
        </property>

    </bean>

    <!--配置RoleService  这里为啥要配置这个呢，因为
    在RoleServiceImpl中没有用到注解，也就是没有用到@service，
    所以在这里用bean来创建这个容器了-->

    <!--配置RoleService-->
    <bean id="roleService" class="com.ittaike.service.impl.RoleServiceImpl">
        <property name="roleDao" ref="roleDao"></property>
    </bean>

    <!--配置RoleDao-->
    <bean id="roleDao" class="com.ittaike.dao.impl.RoleDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>
</beans>

下面是jdbc.properties

#jdbc.driver=com.mysql.jdbc.Driver
#jdbc.url=jdbc:mysql://localhost:3306/test
#jdbc.username=root
#jdbc.password=root


jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC
jdbc.username=root
jdbc.password=root

在这里插入图片描述
最后这个图片，是最后子调试的时候查看了一下这个项目里面的WEB-INF下面的lib里面是否含有mysql-connector-java-8.0.13.jar的这个驱动，嘿，刚开始竟然没有，然后通过刚才的那个添加过程加入，系统就可以运行了 E:\ittaike\spring_test\target\spring_test-1.0-SNAPSHOT\WEB-INF\lib