maven-java.lang.ClassNotFoundException：com.mysql.jdbc.driver

Question

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.17</version>
    <type>jar</type>
    <scope>runtime</scope>
</dependency>

String dbClass = "com.mysql.jdbc.Driver";

Class.forName(dbClass);
Connection connection = DriverManager.getConnection(dbUrl,
    username, password);
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(query);
while (resultSet.next()) {
    String tableName = resultSet.getString(1);
    System.out.println("Table name : " + tableName);
}

MySQL jar在我的.m2 repo中，我尝试通过mvn命令行显式添加它，但说它已经存在。

Answer 1

将作用域更改为compile:

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.17</version>
    <type>jar</type>
    <scope>compile</scope>
</dependency>

因为它是默认的作用域，所以它对应于完全放弃作用域定义，所以类型的计数相同：

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.17</version>
</dependency>

请查看以下内容：https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html以获得关于范围确定的详细信息。