无法使用 Spring MVC、c3p0 连接到远程 MYSQL 数据库

Question

我有一个 spring mvc 项目并连接到 Maria DB 10.11.0-MariaDB。 我可以使用 mysql 工作台连接到远程数据库，但不能使用 spring mvc 和 c3p0。 我确定用户名、密码、端口和 IP，因为我能够通过 mysql 工作台连接

下面是我的 DAO 和 pom xml 配置。

<bean id="Master" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> 
    <property name="driverClass" value="com.mysql.jdbc.Driver"/> 
    <property   name="jdbcUrl" value="jdbc:mysql://<DBIP>:3306/master_db"/> 
    <property name="user" value="xxxxxx"/>
    <property name="password" value="xxxxxxx"/>
    <property name="initialPoolSize" value="1"/>
    <property name="maxPoolSize" value="100"/>
    <property name="minPoolSize" value="2"/>
    <property name="maxIdleTime" value="3600"/>
      <!--   <property name="maxIdleTimeExcessConnections" value="30"/>-->
    <property name="numHelperThreads" value="6"/> 
</bean>

    <dependencies>
        <!-- Spring -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.4</version>
        
        </dependency>

        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-all</artifactId>
            <version>1.3</version>
        </dependency>

        <!-- Core utilities used by other modules. Define this if you use Spring 
            Utility APIs (org.springframework.core.*/org.springframework.util.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Expression Language (depends on spring-core) Define this if you use 
            Spring Expression APIs (org.springframework.expression.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Bean Factory and JavaBeans utilities (depends on spring-core) Define 
            this if you use Spring Bean APIs (org.springframework.beans.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Aspect Oriented Programming (AOP) Framework (depends on spring-core, 
            spring-beans) Define this if you use Spring AOP APIs (org.springframework.aop.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Application Context (depends on spring-core, spring-expression, spring-aop, 
            spring-beans) This is the central artifact for Spring's Dependency Injection 
            Container and is generally always defined -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Various Application Context utilities, including EhCache, JavaMail, 
            Quartz, and Freemarker integration Define this if you need any of these integrations -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Transaction Management Abstraction (depends on spring-core, spring-beans, 
            spring-aop, spring-context) Define this if you use Spring Transactions or 
            DAO Exception Hierarchy (org.springframework.transaction.*/org.springframework.dao.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- JDBC Data Access Library (depends on spring-core, spring-beans, spring-context, 
            spring-tx) Define this if you use Spring's JdbcTemplate API (org.springframework.jdbc.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        
         <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>

        <!-- Object-to-Relation-Mapping (ORM) integration with Hibernate, JPA, 
            and iBatis. (depends on spring-core, spring-beans, spring-context, spring-tx) 
            Define this if you need ORM (org.springframework.orm.*) -->
<!--        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency> -->

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>5.3.20</version>
        </dependency>
        
        <!-- Object-to-XML Mapping (OXM) abstraction and integration with JAXB, 
            JiBX, Castor, XStream, and XML Beans. (depends on spring-core, spring-beans, 
            spring-context) Define this if you need OXM (org.springframework.oxm.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Web application development utilities applicable to both Servlet and 
            Portlet Environments (depends on spring-core, spring-beans, spring-context) 
            Define this if you use Spring MVC, or wish to use Struts, JSF, or another 
            web framework with Spring (org.springframework.web.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Spring MVC for Servlet Environments (depends on spring-core, spring-beans, 
            spring-context, spring-web) Define this if you use Spring MVC with a Servlet 
            Container such as Apache Tomcat (org.springframework.web.servlet.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- Spring MVC for Portlet Environments (depends on spring-core, spring-beans, 
            spring-context, spring-web) Define this if you use Spring MVC with a Portlet 
            Container (org.springframework.web.portlet.*) -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc-portlet</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.9.2</version>
        </dependency>


        <!-- Support for testing Spring applications with tools such as JUnit and 
            TestNG This artifact is generally always defined with a 'test' scope for 
            the integration testing framework and unit testing stubs -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20141113</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.13</version>
        </dependency> 
         
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.4</version>
        </dependency>

        
            <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.6</version>
            </dependency>


        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.9</version>
        </dependency>


        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>javax.mail-api</artifactId>
            <version>1.5.5</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>myapp</finalName>
        <sourceDirectory>src</sourceDirectory>
    
        <resources>
            <resource>
                <directory>src</directory>
            </resource>
        </resources>

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.4.2</version>
            </plugin>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.1</version>
                <configuration>
                    <url>http://localhost:8080/manager/html</url>
                    <server>tomcat7</server>
                    <contextReloadable>true</contextReloadable>
                     <warSourceDirectory>WebContent/WEB-INF</warSourceDirectory>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.0</version>
                <configuration>
                    <source>${jdk.version}</source>
                    <target>${jdk.version}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                    <!-- <webXml>WebContent\WEB-INF\web.xml</webXml> -->
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                <version>2.10.3</version>
                <configuration>
                    <show>private</show>
                    <nohelp>true</nohelp>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>findbugs-maven-plugin</artifactId>
                <version>${findbugs.version}</version>
                <configuration>

                    <!-- Enables analysis which takes more memory but finds more bugs. If 
                        you run out of memory, changes the value of the effort element to 'Low'. -->

                    <effort>Max</effort>

                    <failOnError>false</failOnError>
                    <!-- Reports all bugs (other values are medium and max) -->
                    <threshold>max</threshold>
                    <!-- Produces XML report -->
                    <xmlOutput>true</xmlOutput>
                    <!-- Configures the directory in which the XML report is created -->
                    <findbugsXmlOutputDirectory>${project.build.directory}/findbugs</findbugsXmlOutputDirectory>
                </configuration>

            </plugin>

        </plugins>
    </build>

    <reporting>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>findbugs-maven-plugin</artifactId>
                <version>${findbugs.version}</version>
            </plugin>
        </plugins>
    </reporting>
</project>

我遇到以下异常：

18:28:04,626 DEBUG JdbcTemplate:435 - Executing SQL query [SELECT * FROM client`]
18:28:04,972  INFO AbstractPoolBackedDataSource:462 - Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1hgeknaat1k2sq9317m1swv|a737736, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hgeknaat1k2sq9317m1swv|a737736, idleConnectionTestPeriod -> 0, initialPoolSize -> 1, jdbcUrl -> jdbc:mysql://xx.xxx.xx.xx:3306/master_db, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 3600, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 2, numHelperThreads -> 6, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
18:29:00,596 DEBUG SqlUtils:99 - Converting Throwable to SQLException...
com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.

Answer 1

方案一：去掉这些代码，让C3P0默认值先测试。 然后你用正确的值更新

<property name="initialPoolSize" value="1"/>
<property name="maxPoolSize" value="100"/>
<property name="minPoolSize" value="2"/>
<property name="maxIdleTime" value="3600"/>

解决方案 2 ：您复制/粘贴此

mysql://xx.xxx.xx.xx:3306/price_check_v2_master_db

在你的例外中，你在你的代码中得到这个

jdbc:mysql://:3306/master_db

不同的数据库名称：price_check_v2_master_db VS master_db。 也许这就是问题的来源