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问java.lang.ClassNotFoundException:引发的com.mysql.jdbc.Driver异常，即使将依赖项添加到pom.xml并注册了驱动程序
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Stack Overflow用户

提问于 2022-03-25 21:46:34

回答 1查看 318关注 0票数 0

由于某些原因，我不知道我的项目正在抛出一个

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

异常。在过去的几天里，我一直在寻找解决这个问题的答案。这是我的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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.vaadin.example</groupId>
    <artifactId>database-example</artifactId>
    <name>Database example</name>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <vaadin.version>14.8.6</vaadin.version>

    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
    </parent>

    <repositories>
        <!-- The order of definitions matters. Explicitly defining central here 
            to make sure it has the highest priority. -->

        <!-- Main Maven repository -->
        <repository>
            <id>central</id>
            <url>https://repo.maven.apache.org/maven2</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <!-- Repository used by many Vaadin add-ons -->
        <repository>
            <id>Vaadin Directory</id>
            <url>https://maven.vaadin.com/vaadin-addons</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

    <pluginRepositories>
        <!-- Main Maven repository -->
        <pluginRepository>
            <id>central</id>
            <url>https://repo.maven.apache.org/maven2</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-bom</artifactId>
                <version>${vaadin.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.28</version>
            </dependency>
        </dependencies>
    </dependencyManagement>



    <dependencies>
        <dependency>
            <groupId>com.vaadin</groupId>
            <!-- Replace artifactId with vaadin-core to use only free components -->
            <artifactId>vaadin</artifactId>
            <exclusions>
                <!-- Webjars are only needed when running in Vaadin 13 compatibility 
                    mode -->
                <exclusion>
                    <groupId>com.vaadin.webjar</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.insites</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.polymer</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.polymerelements</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.vaadin</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.webcomponents</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
            </exclusions>
        </dependency>



        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-spring-boot-starter</artifactId>
            <exclusions>
                <!-- Excluding so that webjars are not included. -->
                <exclusion>
                    <groupId>com.vaadin</groupId>
                    <artifactId>vaadin-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

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

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>

    <build>
        <defaultGoal>spring-boot:run</defaultGoal>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <!-- Clean build and startup time for Vaadin apps sometimes may exceed 
                    the default Spring Boot's 30sec timeout. -->
                <configuration>
                    <wait>500</wait>
                    <maxAttempts>240</maxAttempts>
                </configuration>
            </plugin>

            <!-- Take care of synchronizing java dependencies and imports in package.json 
                and main.js files. It also creates webpack.config.js if not exists yet. -->
            <plugin>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-maven-plugin</artifactId>
                <version>${vaadin.version}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>prepare-frontend</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <profiles>
        <profile>
            <!-- Production mode is activated using -Pproduction -->
            <id>production</id>
            <properties>
                <vaadin.productionMode>true</vaadin.productionMode>
            </properties>

            <dependencies>
                <dependency>
                    <groupId>com.vaadin</groupId>
                    <artifactId>flow-server-production-mode</artifactId>
                </dependency>
            </dependencies>

            <build>
                <plugins>
                    <plugin>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-maven-plugin</artifactId>
                        <configuration>
                            <jvmArguments>-Dvaadin.productionMode</jvmArguments>
                        </configuration>
                    </plugin>
                    <plugin>
                        <groupId>com.vaadin</groupId>
                        <artifactId>vaadin-maven-plugin</artifactId>
                        <version>${vaadin.version}</version>
                        <executions>
                            <execution>
                                <goals>
                                    <goal>build-frontend</goal>
                                </goals>
                                <phase>compile</phase>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
</project>

以及连接到数据库的类：

package com.availaboard.engine.sql_connection;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import com.availaboard.engine.resource.Resource;
import com.availaboard.engine.resource.Status;
import com.availaboard.utilitys.ConfigPropReader;

public class AvailaboardSQLConnection {

    ConfigPropReader config = new ConfigPropReader();
    public final String username = config.getPropValues().get(0);
    private final String password = config.getPropValues().get(1);
    private final String url = config.getPropValues().get(2);

    /*
     * Load all resources from the database
     */
    public ArrayList<Resource> loadResources() {
        ArrayList<Resource> arr = new ArrayList<Resource>();
        try {
            String query = "select ResourceID from resource";
            Class.forName("com.mysql.cj.jdbc.Driver");
            final Connection con = DriverManager.getConnection(this.url, this.username, this.password);
            PreparedStatement st = con.prepareStatement(query);
            ResultSet rs = st.executeQuery();
            if (rs.next()) {
                Resource res = createResourceWithID(rs.getInt(1));
                arr.add(res);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return arr;
    }

    public Resource createResourceWithID(int ID) {
        System.out.println(ID);
        try {
            String query = "select name, contact, ResourceID from resource where ResourceID = ?";
            Class.forName("com.mysql.cj.jdbc.Driver");
            final Connection con = DriverManager.getConnection(this.url, this.username, this.password);
            PreparedStatement st = con.prepareStatement(query);
            st.setInt(1, ID);
            ResultSet rs = st.executeQuery();
            if (rs.next()) {
                Resource res = new Resource();
                res.setName(rs.getString(1));
                res.setContact(rs.getString(2));
                res.setId(rs.getInt(3));
                return res;
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}

以下是完整的错误消息，以防有帮助：

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    at org.springframework.boot.devtools.restart.classloader.RestartClassLoader.loadClass(RestartClassLoader.java:144)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:315)
    at com.availaboard.engine.sql_connection.AvailaboardSQLConnection.loadResources(AvailaboardSQLConnection.java:27)
    at com.availaboard.UI.Availaboard.setUpGrid(Availaboard.java:47)
    at com.availaboard.UI.Availaboard.<init>(Availaboard.java:30)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:200)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1312)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1214)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:307)
    at com.vaadin.flow.spring.SpringInstantiator.getOrCreate(SpringInstantiator.java:117)
    at com.vaadin.flow.di.Instantiator.createRouteTarget(Instantiator.java:165)
    at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.lambda$getRouteTarget$1(AbstractNavigationStateRenderer.java:139)
    at java.base/java.util.Optional.orElseGet(Optional.java:369)
    at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.getRouteTarget(AbstractNavigationStateRenderer.java:138)
    at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.sendBeforeEnterEventAndPopulateChain(AbstractNavigationStateRenderer.java:528)
    at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.createChainIfEmptyAndExecuteBeforeEnterNavigation(AbstractNavigationStateRenderer.java:508)
    at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.handle(AbstractNavigationStateRenderer.java:225)
    at com.vaadin.flow.router.Router.handleNavigation(Router.java:261)
    at com.vaadin.flow.router.Router.navigate(Router.java:232)
    at com.vaadin.flow.router.Router.navigate(Router.java:198)
    at com.vaadin.flow.router.Router.initializeUI(Router.java:95)
    at com.vaadin.flow.server.BootstrapHandler.initializeUIWithRouter(BootstrapHandler.java:1625)
    at com.vaadin.flow.server.BootstrapHandler.createAndInitUI(BootstrapHandler.java:1618)
    at com.vaadin.flow.server.BootstrapHandler.synchronizedHandleRequest(BootstrapHandler.java:508)
    at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
    at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1578)
    at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:252)
    at com.vaadin.flow.spring.SpringServlet.service(SpringServlet.java:111)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:459)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:352)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
    at org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141)
    at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177)
    at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:834)
2022-03-25 14:37:13.946  INFO 2112 --- [nio-8080-exec-2] c.vaadin.flow.router.RouteNotFoundError  : Couldn't find route for 'sw.js'

我已经经历了无数的选择，我尝试在本地向我的项目中添加一个jar文件，遍历多个不同版本的依赖项，并使用多种不同的方式加载驱动程序。目标是代码连接到我的数据库(托管在本地)，并将数据带回并显示在我的网页上。网页运行良好，只是连接到数据库就会产生问题。

更新的POM.XML：

<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>com.vaadin.example</groupId>
    <artifactId>database-example</artifactId>
    <name>Database example</name>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <vaadin.version>14.8.6</vaadin.version>

    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
    </parent>

    <repositories>
        <!-- The order of definitions matters. Explicitly defining central here 
            to make sure it has the highest priority. -->

        <!-- Main Maven repository -->
        <repository>
            <id>central</id>
            <url>https://repo.maven.apache.org/maven2</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <!-- Repository used by many Vaadin add-ons -->
        <repository>
            <id>Vaadin Directory</id>
            <url>https://maven.vaadin.com/vaadin-addons</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

    <pluginRepositories>
        <!-- Main Maven repository -->
        <pluginRepository>
            <id>central</id>
            <url>https://repo.maven.apache.org/maven2</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-bom</artifactId>
                <version>${vaadin.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.28</version>
            </dependency>
        </dependencies>
    </dependencyManagement>



    <dependencies>
        <dependency>
            <groupId>com.vaadin</groupId>
            <!-- Replace artifactId with vaadin-core to use only free components -->
            <artifactId>vaadin</artifactId>
            <exclusions>
                <!-- Webjars are only needed when running in Vaadin 13 compatibility 
                    mode -->
                <exclusion>
                    <groupId>com.vaadin.webjar</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.insites</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.polymer</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.polymerelements</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.vaadin</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.webjars.bowergithub.webcomponents</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
            </exclusions>
        </dependency>



        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-spring-boot-starter</artifactId>
            <exclusions>
                <!-- Excluding so that webjars are not included. -->
                <exclusion>
                    <groupId>com.vaadin</groupId>
                    <artifactId>vaadin-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

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

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>

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

    </dependencies>

    <build>
        <defaultGoal>spring-boot:run</defaultGoal>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <!-- Clean build and startup time for Vaadin apps sometimes may exceed 
                    the default Spring Boot's 30sec timeout. -->
                <configuration>
                    <wait>500</wait>
                    <maxAttempts>240</maxAttempts>
                </configuration>
            </plugin>

            <!-- Take care of synchronizing java dependencies and imports in package.json 
                and main.js files. It also creates webpack.config.js if not exists yet. -->
            <plugin>
                <groupId>com.vaadin</groupId>
                <artifactId>vaadin-maven-plugin</artifactId>
                <version>${vaadin.version}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>prepare-frontend</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <profiles>
        <profile>
            <!-- Production mode is activated using -Pproduction -->
            <id>production</id>
            <properties>
                <vaadin.productionMode>true</vaadin.productionMode>
            </properties>

            <dependencies>
                <dependency>
                    <groupId>com.vaadin</groupId>
                    <artifactId>flow-server-production-mode</artifactId>
                </dependency>
            </dependencies>

            <build>
                <plugins>
                    <plugin>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-maven-plugin</artifactId>
                        <configuration>
                            <jvmArguments>-Dvaadin.productionMode</jvmArguments>
                        </configuration>
                    </plugin>
                    <plugin>
                        <groupId>com.vaadin</groupId>
                        <artifactId>vaadin-maven-plugin</artifactId>
                        <version>${vaadin.version}</version>
                        <executions>
                            <execution>
                                <goals>
                                    <goal>build-frontend</goal>
                                </goals>
                                <phase>compile</phase>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
</project>```
> `Blockquote`

java

database

maven

回答 1

Stack Overflow用户

发布于 2022-03-25 21:53:41

您在MySQL部分中包含了<dependencyManagement>，它允许您全局指定版本。

这实际上并没有指定依赖项。您仍然需要将其包含在<dependencies>部分中，现在可以省略该版本，除非由于某种原因它与全局值不同。

票数 2

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原文链接：

https://stackoverflow.com/questions/71623447

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