DataSourceDriverLoader

Interface Purpose

To resolve conflicts in big data suites, this interface provides an interceptor that intercepts the ClassLoader of the target driver and sets it directly into the DataSource.

Interface Definition

Main Interface

package com.fr.stable.fun;

import com.fr.stable.fun.mark.Mutable;

/**
 * ClassLoader interceptor provided for plugins
 */
public interface DataSourceDriverLoader extends Mutable {

    // Determines whether the target driver is matched
    boolean isInterceptAllowed(String databaseType, String url);

    // Returns the specific ClassLoader
    ClassLoader getClassLoader();
}

Related Interfaces

Utility class that calls this interface:

package com.fr.stable.fun.impl;

import com.fr.plugin.ExtraClassManager;
import com.fr.stable.fun.DataSourceDriverLoader;

import java.util.Set;

/**
 * Utility class that invokes the interface
 */
public class DataSourceDriverLoaderUtils {

    public static ClassLoader getClassLoader(String databaseType, String url) {
        Set<DataSourceDriverLoader> dataSourceDriverLoaders = getDataSourceDriverLoader();
        // Non-null means the plugin was loaded successfully
        if (dataSourceDriverLoaders != null && !dataSourceDriverLoaders.isEmpty()) {
            FineLoggerFactory.getLogger().debug("====== loading classloader plugin ======");
            for (DataSourceDriverLoader datasourceDriverLoader : dataSourceDriverLoaders) {
                // Check if it matches the target driver using url and databaseType for more precise matching
                if (datasourceDriverLoader.isInterceptAllowed(databaseType, url)) {
                    ClassLoader classLoader = datasourceDriverLoader.getClassLoader();
                    return classLoader;
                }
            }
        }
        return null;
    }

    private static Set<DataSourceDriverLoader> getDataSourceDriverLoader() {
        return ExtraClassManager.getInstance().getArray(DataSourceDriverLoader.XML_TAG);
    }
}

Plugin Registration

<extra-core>
    <DataSourceDriverLoader class="com.fr.plugin.dialect.classloader.{$DatabaseName}ClassLoaderHandler"/>
</extra-core>

Interface Example

Example source code: demo-driver-loader

The demo outputs log information when the target driver is successfully matched.

Notes

1. The ClassLoader is only set into the DataSource if the implemented ClassLoader is non-null
2. The latest 2.0 isolation plugin requires FR 10.15 or above (release 5.1.2 or later)