mysql-connector-j library is required for proper exception handling for mariadb mode

[johnB96]

Describe the bug

Say I have a connection string in the following manner: jdbc:aws-wrapper:mariadb://db-host/db_name

To me, this implies that I only need the mariadb-java-client library.

However, given the MariaDBExceptionHandler extends MySQLExceptionHandler creates an implied dependency on mysql-connector-j. Because MySQLExceptionHandler has a reference to com.mysql.cj.exceptions.CJException

However, we deliberately want to avoid using the mysql-connector-j driver due to the GPL license and instead want to only mariadb-java-client. Therefore, MariaDBExceptionHandler should be written in a manner to not require mysql-connector-j.

Expected Behavior

I expected proper exception handling.

What plugins are used? What other connection properties were set?

wrapperPlugins=iam

Current Behavior

Today, I get a class not defined exception

Caused by: java.lang.NoClassDefFoundError: com/mysql/cj/exceptions/CJException
	at software.amazon.jdbc.exceptions.MySQLExceptionHandler.isLoginException(MySQLExceptionHandler.java:78)
	at software.amazon.jdbc.exceptions.ExceptionManager.isLoginException(ExceptionManager.java:35)

Reproduction Steps

get a connection error while running the mariadb driver

Possible Solution

Rewrite the MariaDBExceptionHandler to not reference com.mysql.cj.exceptions.CJException

Additional Information/Context

No response

The AWS Advanced JDBC Driver version used

2.5.4

JDK version used

openjdk 23.0.2 2025-01-21 OpenJDK Runtime Environment Zulu23.32+11-CA (build 23.0.2+7) OpenJDK 64-Bit Server VM Zulu23.32+11-CA (build 23.0.2+7, mixed mode, sharing)

Operating System and version

ProductName: macOS ProductVersion: 15.3.1 BuildVersion: 24D70

[sergiyvamz]

Hi @johnB96

Could you please verify if the latest changes address the issue for you? You can find the latest change in the snapshot build. More information on how to use the snapshot build is available here.

Thank you!

[johnB96]

@sergiyvamz, thanks for the quick response on this. I'll verify within the next 2 days.

[johnB96]

@sergiyvamz, this didn't fix it as MariaDBExceptionHandler still extends MySQLExceptionHandler and has a reference to com.mysql.cj.exceptions.CJException

Here's a simple test case I made

  @Test
  public void testClassRequirements() {
    MariaDBExceptionHandler mariaDBExceptionHandler = new MariaDBExceptionHandler();
    mariaDBExceptionHandler.isNetworkException(new RuntimeException("test"));
  }

java.lang.NoClassDefFoundError: com/mysql/cj/exceptions/CJException

	at software.amazon.jdbc.exceptions.MySQLExceptionHandler.isNetworkException(MySQLExceptionHandler.java:47)
	at com.myproject.Tests.testClassRequirements(Tests.java:28)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:54)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)
Caused by: java.lang.ClassNotFoundException: com.mysql.cj.exceptions.CJException
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
	... 30 more

[sergiyvamz]

Hi @johnB96

I'm afraid you're checking a wrong version of the driver. The fix is merged but it hasn't been released yet. The latest version of the driver is 2.5.4 and it doesn't include the fix. You need to check our snapshot build that contains the fix.
https://github.com/aws/aws-advanced-jdbc-wrapper/blob/main/docs/using-the-jdbc-driver/UsingTheJdbcDriver.md#using-a-snapshot-of-the-driver

As you can see there's no references to CJException in MySQLExceptionHandler.
https://github.com/aws/aws-advanced-jdbc-wrapper/blob/main/wrapper/src/main/java/software/amazon/jdbc/exceptions/MySQLExceptionHandler.java

CJException is used by MysqlConnectorJDriverHelper and this class instantiates just in the case of using mysql-connector-j.
https://github.com/aws/aws-advanced-jdbc-wrapper/blob/main/wrapper/src/main/java/software/amazon/jdbc/targetdriverdialect/MysqlConnectorJDriverHelper.java

Would you please double check?

[johnB96]

@sergiyvamz, I grabbed a snapshot that was too old. Once I took the snapshot from Feb 18th it worked perfectly. Thanks for taking a look at this!

We can consider the issue fixed, thanks again!