使用Maven SQL Plugin遇Access Denied错误，寻求解决方案

Let's break down your issue step by step—there's a clear mismatch between your plugin configuration and the actual database your application is trying to connect to, which is causing the access denied error.

Key Observation from the Exception #

Looking at your stack trace, all the error classes are from com.mysql.jdbc.*:

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:996)
...

But your maven-sql-plugin configuration explicitly uses the H2 database (driver org.h2.Driver and H2-specific JDBC URL). This means one of two things:

• Your plugin configuration isn't being applied, and your test code/another component is hardcoding a MySQL connection.
• There's a conflicting configuration elsewhere in your project that's overriding the H2 setup.

Issues in Your Plugin Configuration #

Let's go through your plugin setup to spot problems:

1. Misplaced GRANT Statement:
   You added a MySQL-style GRANT command in <sqlCommand>, but H2 doesn't require this. The default root/root user in H2 has full permissions out of the box. This statement is irrelevant for H2 and could cause unexpected errors.
2. Potential Path Permissions:
   Your H2 file URL is jdbc:h2:file:target/db/employee—ensure the target/db directory can be created by Maven (no filesystem permission issues) when running the plugin.

Fix Steps to Resolve the Error #

Option 1: Stick with H2 Database (as configured in your plugin) #

1. Align Test Code with Plugin Configuration:
   Double-check your test classes or any application-level datasource configs—make sure they're using the same H2 driver, URL, credentials as your plugin:
   • Driver: org.h2.Driver
   • URL: jdbc:h2:file:target/db/employee;DB_CLOSE_DELAY=-1;DATABASE_TO_UPPER=false;FILE_LOCK=NO;INIT=CREATE SCHEMA IF NOT EXISTS employee\;SET SCHEMA employee
   • Username/Password: root/root
2. Remove the MySQL GRANT Statement:
   Delete the <sqlCommand> block from your plugin configuration—it's not needed for H2.
3. Verify H2 Connection Manually:
   Use the H2 Console to test the connection:
   • Download the H2 jar, run java -jar h2-x.x.x.jar
   • Enter your JDBC URL, username, password, and click "Connect". If this fails, fix the URL/path first.

Option 2: Switch to MySQL (if that's your intended database) #

If you actually want to use MySQL instead of H2:

1. Update Plugin Configuration:
   Uncomment the MySQL driver and URL, comment out H2 settings:

   <plugin>
     <groupId>org.codehaus.mojo</groupId>
     <artifactId>sql-maven-plugin</artifactId>
     <version>1.5</version>
     <executions>
       <execution>
         <id>create-database</id>
         <phase>pre-integration-test</phase>
         <goals>
           <goal>execute</goal>
         </goals>
         <configuration>
           <!--<driver>org.h2.Driver</driver>-->
           <driver>com.mysql.jdbc.Driver</driver>
           <url>jdbc:mysql://localhost:3306/employee?createDatabaseIfNotExist=true</url>
           <username>root</username>
           <password>root</password>
           <srcFiles>
             <srcFile>src/test/resources/employee.sql</srcFile>
           </srcFiles>
           <!-- Fix the GRANT syntax for MySQL -->
           <sqlCommand>GRANT ALL PRIVILEGES ON employee.* TO 'root'@'localhost' IDENTIFIED BY 'root' WITH GRANT OPTION;</sqlCommand>
         </configuration>
       </execution>
     </executions>
     <dependencies>
       <!--<dependency>
         <groupId>com.h2database</groupId>
         <artifactId>h2</artifactId>
         <version>1.3.166</version>
       </dependency>-->
       <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <version>5.1.18</version>
       </dependency>
     </dependencies>
   </plugin>
   

2. Validate MySQL User Access:
   • Ensure MySQL server is running locally on port 3306.
   • Log into MySQL manually with mysql -u root -p and enter password root—if this fails, reset the root password or fix user permissions in MySQL.
   • Run the corrected GRANT statement directly in MySQL to ensure the user has access to the employee database.

Your Original Plugin Configuration (for reference) #

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>sql-maven-plugin</artifactId>
  <version>1.5</version>
  <executions>
    <execution>
      <id>create-database</id>
      <phase>pre-integration-test</phase>
      <goals>
        <goal>execute</goal>
      </goals>
      <configuration>
        <driver>org.h2.Driver</driver>
        <!--<driver>com.mysql.jdbc.Driver</driver> -->
        <url>jdbc:h2:file:target/db/employee;DB_CLOSE_DELAY=-1;DATABASE_TO_UPPER=false;FILE_LOCK=NO;INIT=CREATE SCHEMA IF NOT EXISTS employee\;SET SCHEMA employee</url>
        <username>root</username>
        <password>root</password>
        <srcFiles>
          <srcFile>src/test/resources/employee.sql</srcFile>
        </srcFiles>
        <sqlCommand>${GRANT ALL PRIVILEGES ON . TO 'root'@'localhost' IDENTIFIED BY 'root' WITH GRANT OPTION}</sqlCommand>
      </configuration>
    </execution>
  </executions>
  <dependencies>
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <version>1.3.166</version>
    </dependency>
    <!--<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.18</version>
    </dependency> -->
  </dependencies>
</plugin>

Your Original Exception Stack Trace (for reference) #

[com.mchange.v2.resourcepool.BasicResourcePool:run-1851] - com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@462393ff -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:996)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3887)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3823)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:870)
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1659)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1206)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2234)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2265)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2064)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
	at sun.reflect.GeneratedConstructorAccessor4.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:395)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
	at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)

内容的提问来源于stack exchange，提问作者Sat